U.S. patent application number 12/560330 was filed with the patent office on 2010-03-25 for mobile nitrogen generation device.
This patent application is currently assigned to PACIFIC CONSOLIDATED INDUSTRIES, LLC. Invention is credited to Brian Chung, Herman Theodore Marwitz, Keith Michael, David Scheierl, Terry Wheaton, James Yang.
Application Number | 20100071561 12/560330 |
Document ID | / |
Family ID | 37669531 |
Filed Date | 2010-03-25 |
United States Patent
Application |
20100071561 |
Kind Code |
A1 |
Marwitz; Herman Theodore ;
et al. |
March 25, 2010 |
MOBILE NITROGEN GENERATION DEVICE
Abstract
A mobile inert gas generator can include various components
supported by a wheeled vehicle. The generator can include a feed
air compressor, a separation device for separating an inert gas
from a feed air gas, and a booster compressor, each of which can
have various sensors and actuators for controlling the operation
thereof. An electronic control system can be connected to the
sensors and actuators to allow for convenient operation of the
generator. The electronic control system can include a control
panel disposed in a cab.
Inventors: |
Marwitz; Herman Theodore;
(Riverside, CA) ; Wheaton; Terry; (Corona, CA)
; Chung; Brian; (Mission Viejo, CA) ; Scheierl;
David; (Corona, CA) ; Yang; James; (Santa Ana,
CA) ; Michael; Keith; (West Chester, PA) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
2040 MAIN STREET, FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Assignee: |
PACIFIC CONSOLIDATED INDUSTRIES,
LLC
Riverside
CA
|
Family ID: |
37669531 |
Appl. No.: |
12/560330 |
Filed: |
September 15, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11489698 |
Jul 19, 2006 |
7588612 |
|
|
12560330 |
|
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|
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60700672 |
Jul 19, 2005 |
|
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60812843 |
Jun 12, 2006 |
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Current U.S.
Class: |
96/401 ;
96/402 |
Current CPC
Class: |
B01D 53/75 20130101;
B01D 53/229 20130101 |
Class at
Publication: |
96/401 ;
96/402 |
International
Class: |
B01D 50/00 20060101
B01D050/00 |
Claims
1-30. (canceled)
31. A system configured to separate an inert gas from atmospheric
air comprising: a feed air compressor configured to compress and
thereby raise a pressure of atmospheric air; a separation device
configured to separate the inert gas from the pressurized
atmospheric air from the feed air compressor; a booster compressor
configured to raise a pressure of the inert gas from the separation
device; at least a first sensor configured to detect an operational
parameter of the feed air compressor; a least a second sensor
configured to detect an operational parameter related to the
operation of the separation device; at least a third sensor
configured to contact an operational parameter of the booster
compressor; and an electronic control system being connected to the
first, second, and third sensors, the electronic control system
comprising a display device configured to display a graphical user
interface having at least first, second, and third screens; wherein
the first screen includes a plurality of data related to the
operation of the feed air compressor including data indicative of
the output of the first sensor, the second screen including a
plurality of data related to the operation of the separation device
including data indicative of the output of the second sensor, and
the third screen including a plurality of data related to the
operation of the booster compressor including data indicative of
the output of the third sensor.
32. The system according to claim 31 additionally comprising a
fourth sensor configured contact a condition external to the
system, electronic control system being connected to the fourth
sensor and configured to display data indicative of the output of
the fourth sensor.
33. The system according to claim 31 additionally comprising a
wheeled vehicle supporting the feed air compressor, the separation
device, the booster compressor, the first sensor, the second
sensor, the third sensor, and the electronic control system.
34-40. (canceled)
41. The system of claim 31, wherein the graphical user interface
includes a touch screen device and displays the first, second, and
third screens on the touch screen device.
42. The system of claim 31, wherein the first screen includes a
display of an output of at least one of a compressor discharge
pressure sensor, a nitrogen flow sensor, a compressor outlet
temperature sensor, a nitrogen purity sensor, and a booster inlet
temperature sensor.
43. The system of claim 42, wherein the first screen includes a
compressor discharge pressure field, a nitrogen flow field, a
compressor outlet temperature field, a nitrogen purity field, and a
booster inlet temperature field for displaying outputs of the
respective one of the compressor discharge pressure sensor, the
nitrogen flow sensor, the compressor outlet temperature sensor, the
nitrogen purity sensor, and the booster inlet temperature
sensor.
44. The system of claim 31, further comprising a feed air
compressor actuator group being connected to the feed air
compressor and being configured to control at least one operational
parameter of the feed air compressor, the feed air compressor
actuator group including at least one of a combustion air valve for
controlling the flow of air into the engine, an engine speed
control actuator, a starter switch, and an unloading valve.
45. The system of claim 44, wherein the electronic control system
is operative to provide an output to the feed air compressor
actuator group for controlling an operational parameter of the feed
air compressor.
46. The system of claim 45, wherein the graphical user interface
includes a touch screen device and displays the first screen on the
touch screen device, the touch screen device being in electrical
communication with the electronic control system and being
operative to receive an input from a user for selectively
controlling at least one operational parameter of the feed air
compressor displayed in the first screen, the touch screen further
being operative to communicate the input to the electronic control
system, the electronic control system providing an output to the
feed air compressor actuator group being representative of the
input of the user.
47. The system of claim 31, wherein the second screen includes a
display of an output of at least one of a compressor outlet
temperature sensor, a nitrogen purity sensor, a nitrogen flow
sensor, a heater outlet temperature sensor, a heater inlet
temperature sensor, and a membrane inlet temperature sensor.
48. The system of claim 47, wherein the second screen includes a
compressor outlet temperature field, a nitrogen purity field, a
nitrogen flow field, a heater outlet temperature field, a heater
inlet temperature field, and a membrane inlet temperature field for
displaying outputs of the respective one of the compressor outlet
temperature sensor, the nitrogen purity sensor, the nitrogen flow
sensor, the heater outlet temperature sensor, the heater inlet
temperature sensor, and the membrane inlet temperature sensor.
49. The system of claim 31, further comprising a membrane actuator
group being connected to the membrane separation unit and being
configured to control at least one operational parameter of the
membrane separation unit, the membrane actuator group including at
least one of a flow control valve and a dump valve.
50. The system of claim 49, wherein the electronic control system
is operative to provide an output to the membrane actuator group
for controlling an operational parameter of the membrane separation
unit.
51. The system of claim 50, wherein the graphical user interface
includes a touch screen device and displays the second screen on
the touch screen device, the touch screen device being in
electrical communication with the electronic control system and
being operative to receive an input from a user for selectively
controlling at least one operational parameter of the membrane
separation unit displayed in the second screen, the touch screen
further being operative to communicate the input to the electronic
control system, the electronic control system providing an output
to the membrane actuator group being representative of the input of
the user.
52. The system of claim 31, wherein the third screen includes a
display of an output of at least one of a booster inlet pressure
sensor, a booster discharge pressure sensor, a booster inlet
temperature sensor, a booster discharge temperature sensor, a
booster first stage pressure sensor, a booster oil pressure sensor,
a booster first stage temperature sensor, a booster second stage
temperature sensor, a booster third stage temperature sensor, and a
booster second stage pressure sensor.
53. The system of claim 52, wherein the second screen includes a
booster inlet pressure field, a booster discharge pressure field, a
booster inlet temperature field, a booster discharge temperature
field, a booster first stage pressure field, a booster oil pressure
field, a booster first stage temperature field, a booster second
stage temperature field, a booster third stage temperature field,
and a booster second stage pressure field for displaying outputs of
the respective one of the booster inlet pressure sensor, the
booster discharge pressure sensor, the booster inlet temperature
sensor, the booster discharge temperature sensor, the booster first
stage pressure sensor, the booster oil pressure sensor, the booster
first stage temperature sensor, the booster second stage
temperature sensor, the booster third stage temperature sensor, and
the booster second stage pressure sensor.
54. The system of claim 31, further comprising a booster actuator
group being connected to the booster compressor and being
configured to control at least one operational parameter of the
booster compressor, the booster actuator group including actuators
for starting, loading and controlling a pressure output from the
booster compressor.
55. The system of claim 54, wherein the electronic control system
is operative to provide an output to the booster actuator group for
controlling an operational parameter of the booster compressor.
56. The system of claim 55, wherein the graphical user interface
includes a touch screen device and displays the third screen on the
touch screen device, the touch screen device being in electrical
communication with the electronic control system and being
operative to receive an input from a user for selectively
controlling at least one operational parameter of the booster
compressor displayed in the third screen, the touch screen further
being operative to communicate the input to the electronic control
system, the electronic control system providing an output to the
booster actuator group being representative of the input of the
user.
57. The system of claim 31, wherein the graphical user interface is
operative to display a fourth screen including a compressor
discharge pressure field, a nitrogen flow field, a compressor
outlet temperature field, a nitrogen purity field, a booster inlet
temperature field, a heater outlet temperature field, a heater
inlet temperature field, a membrane inlet temperature field, a
booster inlet pressure field, a booster discharge pressure field, a
booster inlet temperature field, a booster discharge temperature
field, a booster first stage pressure field, a booster oil pressure
field, a booster first stage temperature field, a booster second
stage temperature field, a booster third stage temperature field,
and a booster second stage pressure field.
58. The system of claim 31, wherein the graphical user interface
includes a touch screen device being operative to display a device
selection screen, the touch screen device being in electrical
communication with the electronic control system and being
operative to receive an input from a user for selectively
controlling at least one operational parameter of the feed air
compressor, the membrane separation unit, and the booster
compressor displayed in the device selection screen, the touch
screen further being operative to communicate the input to the
electronic control system, the electronic control system providing
an output to the respective ones of the feed air compressor
actuator group, the membrane actuator group, and the booster
actuator group being representative of the input of the user.
59. The system of claim 31, wherein the graphical user interface
includes a touch screen device being operative to display a device
calibration screen, the touch screen device being in electrical
communication with the electronic control system and being
operative to receive an input from a user for selectively setting
at least one calibration parameter of at least one of an oxygen
sensor, a temperature sensor, a pressure sensor, and a flow rate
sensor displayed in the device calibration screen, the touch screen
further being operative to communicate the input to the electronic
control system, the electronic control system calculating a
calibrated measurement for the respective ones of the oxygen
sensor, the temperature sensor, the pressure sensor, and the flow
rate sensor displayed in the device calibration screen.
Description
PRIORITY INFORMATION
[0001] The present application claims priority to U.S. Provisional
Application Ser. No. 60/700,672, filed Jul. 19, 2005 and U.S.
Provisional Application Ser. No. 60/812,843, filed Jun. 12, 2006,
the entire contents of each of which is hereby expressly
incorporated by reference.
BACKGROUND OF THE INVENTIONS
[0002] 1. Field of the Inventions
[0003] The present inventions are directed to systems and methods
for generating inert gas, and more particularly, systems and
methods for producing inert gas on a mobile platform.
[0004] 2. Description of the Related Art
[0005] In the art of drilling, such as drilling for oil or natural
gas, inert gases are commonly used for numerous purposes.
Typically, inert gases are often used to displace oxygen from the
volume of space above a liquid surface in a storage tank used for
storing flammable substances, such as, for example, crude oil.
[0006] Additionally, inert gases are often used to suppress fire or
explosion and prevent corrosion during a drilling operation. For
example, an inert gas such as nitrogen, can be injected into a
borehole during a drilling operation to prevent ignition of
substances within the borehole and to prevent corrosion of the
drill bit.
SUMMARY OF THE INVENTIONS
[0007] In accordance with at least one of the embodiments disclosed
herein, a system can be configured to separate nitrogen from
atmospheric air. The system can comprise a feed air compressor unit
having a screw compressor with an inlet and outlet driven by an
air/fuel engine so as to compress atmospheric air to a pressure of
at least 200 psi at the outlet of the screw compressor. A
filtration assembly can comprise at least first, second, third, and
fourth coalescence filters supported on a filter frame, the first,
second, and third coalescence filtered being connected in series
with an inlet of the first coalescence filter connected to the
outlet of the screw compressor, the first, second, third, and
fourth coalescence filters disposed adjacent to each other on the
filter frame. A carbon tower filter can have an inlet communicating
with an outlet of the carbon tower filter and can be connected to
an inlet of the fourth coalescence filter. The carbon tower filter
can also be disposed in a position that is not spatially between
the third and fourth coalescence filters. A heater device can have
an inlet connected to an outlet of the third coalescence filter and
an outlet connected to an inlet of the carbon tower filter. A
membrane separation assembly can have a plurality of membrane
separation devices arranged in at least first and second vertical
stacks, at least first and second vertical members supporting the
first and second vertical stacks, at least the first vertical
member defining either an inlet or an outlet manifold of a
plurality of the membrane separation devices, an inlet of the
membrane separation assembly being connected to an outlet of the
fourth coalescence filter and being configured to distribute a
filtered gas from the fourth coalescence filter to inlets of a
plurality of the membrane separation devices. The heater device can
be supported by at least one of the first and second vertical
members. A booster compressor can have an inlet connected to an
outlet of the membrane separation assembly and can be configured to
raise a pressure of nitrogen rich gas discharged from the membrane
separation assembly. The booster compressor can also have an engine
driving a compressor device having an outlet. The compressor device
can be configured to raise a pressure of the nitrogen rich gas to
at least 1000 psi. Additionally, a control can have an electronic
control system comprising at least a first sensor configured to
detect an operational parameter of the feed air compressor, at
least a second sensor being configured to detect an operational
parameter of the membrane separation assembly, and at least a third
sensor configured to detect an operational parameter of the booster
compressor. The electronic control system can further comprise an
electronic control unit connected to the first second and third
sensors and can be configured to allow an operator of the
electronic control system to monitor the output of the first,
second, and third sensors. A wheeled vehicle can support the feed
air compressor, the filtration assembly, the carbon tower filter,
the heater device, the membrane separation assembly, the booster
compressor, and the control cab.
[0008] In accordance with at least one of the embodiments disclosed
herein, a system can be configured to separate an inert gas from
atmospheric air. The system can comprise a wheeled vehicle
comprising at least one pair of wheels, a feed air compressor and a
booster compressor, the feed air compressor and the booster
compressor being disposed on opposite sides of the at least one
pair of wheels, in the longitudinal direction of the wheeled
vehicle.
[0009] In accordance with at least one of the embodiments disclosed
herein a system can be configured to separate nitrogen from
atmospheric air. The system can comprise a filter assembly
comprising at least first and second coalescence filters supported
on a first filter support assembly, the first and second
coalescence filters being disposed adjacent to each other.
Additionally, a carbon tower filter device can have an inlet
connected to an outlet of the first coalescence filter and can have
an outlet connected to an inlet of the second coalescence filter,
the carbon tower being disposed in a position that is not spatially
between the first and second coalescence filters.
[0010] In accordance with at least one of the embodiments disclosed
herein a system can be configured to separate a component gas from
atmospheric air. The system can comprise a plurality of membrane
separation devices supported by at least first and second generally
vertical members, wherein at least one of the generally vertical
members define an intake or discharge manifold for the plurality of
membrane separation devices.
[0011] In accordance with at least one of the embodiments disclosed
herein a system can be configured for separating and inert gas from
atmospheric air. The system can comprise at least a first
compressor. At least a first separation device can be configured to
separate the inert gas from atmospheric air, the first separation
device being connected to the first compressor. An electronic
control system can be configured to control an operation of at
least the first compressor. The control system can also comprise at
least one sensor configured to detect an operational parameter of
the first compressor and at least a second sensor configured to
detect an operational parameter of the first separation device. A
wheeled vehicle clone support the first compressor, the first
separation device, and the electronic control system. Additionally,
a third sensor that is not supported by the wheeled vehicle can be
configured to detect a parameter external to the system.
[0012] In accordance with at least one of the embodiments disclosed
herein, a system can be configured to separate an inert gas from
atmospheric air. The system can comprise a feed air compressor
configured to compress and thereby raise a pressure of atmospheric
air. A separation device can be configured to separate the inert
gas from the pressurized atmospheric air from the feed air
compressor. A booster compressor can be configured to raise a
pressure of the inert gas from the separation device. At least a
first sensor can be configured to detect an operational parameter
of the feed air compressor. At least a second sensor can be
configured to detect an operational parameter related to the
operation of the separation device. At least a third sensor can be
configured to detect an operational parameter of the booster
compressor. Additionally, an electronic control system can be
connected to the first, second, and third sensors. The electronic
control system can comprise a display device configured to display
a graphical user interface having at least first, second, and third
screens. The first screen can include a plurality of data related
to the operation of the feed air compressor including data
indicative of the output of the first sensor. The second screen can
include a plurality of data related to the operation of the
separation device including data indicative of the output of the
second sensor. Additionally, the third screen can include a
plurality of data related to the operation of the booster
compressor including data indicative of the output of the third
sensor.
[0013] In accordance with at least one of the embodiments disclosed
herein, a system can be configured to separate an inert gas from
atmospheric air. The system can comprise a feed air compressor
subsystem configured to pressurize atmospheric air. A filter
subsystem can be configured to filter the pressurized air from the
feed air compressor. A separation subsystem can be configured to
separate an inert gas from the pressurized atmospheric air from the
feed air compressor. A booster compressor subsystem can be
configured to raise a pressure of an inert gas discharged from the
separation subsystem. A lubricant circulation subsystem can be
configured to circulate lubricant and from at least one of the feed
air compressor subsystem and the booster compressor subsystem to at
least one of the filter subsystem and the separation subsystem. A
wheeled vehicle can support the feed air compressor subsystem, the
filter subsystem, the separation subsystem, the booster compressor
subsystem, and the lubricant circulation subsystem.
[0014] In accordance with at least one of the embodiments disclosed
herein, a system can be configured to separate inert gas from
atmospheric air. The system can comprise a feed air compressor
having an air fuel engine and an exhaust discharge configured to
guide exhaust gases away from the air fuel engine. The feed air
compressor can have an inlet connected to the exhaust discharge and
can be configured to exhaust gas from the exhaust discharge. A
separation assembly can be configured to separate an inert gas from
the pressurized exhaust gas from the booster compressor. A booster
compressor can be configured to raise a pressure of the inert gas
from the separation assembly. A wheeled vehicle can support the
feed air compressor, the separation assembly, and the booster
compressor.
BRIEF DESCRIPTION OF THE DRAWING
[0015] FIG. 1 is a schematic view of a drilling stem arrangement
showing delivery of an inert gas to a downhole drilling region.
[0016] FIG. 2 is a cross-sectional schematic view of a well with a
horizontally disposed section including casings and upper and lower
liners with an inert rich gas present therein.
[0017] FIG. 3 is a cross-sectional schematic view of an initial
injecting of a cement slurry for cementing a casing within a
well.
[0018] FIG. 4 is a cross-sectional schematic view of the casing of
FIG. 3 with the cement in place to secure the casing within the
well.
[0019] FIG. 5 is a cross-sectional schematic view of a well and
equipment for removing gas and/or oil from a well with the
assistance of an inert rich gas.
[0020] FIG. 6 is a cross-sectional schematic view of a reservoir
and the injection of an inert rich gas to remove gas and/or oil
from the reservoir.
[0021] The above-mentioned and the other features of the inventions
disclosed herein are described below with reference to the drawings
of the preferred embodiments. The illustrated embodiments are
intended to illustrate, but not to limit the inventions. The
drawings contain the following figures:
[0022] FIG. 6A is a schematic diagram of a mobile inert gas
separation system.
[0023] FIG. 7 is a schematic diagram of an embodiment of an inert
gas separation system in which air or exhaust from an engine is
subjected to a separation process to separate inert gas
therefrom.
[0024] FIG. 7A is a schematic illustration of an embodiment of the
separation system of FIG. 7.
[0025] FIG. 7B is a schematic illustration of an embodiment of the
separation system of FIG. 7.
[0026] FIG. 7C is a schematic illustration of another embodiment of
the separation system of FIG. 7.
[0027] FIG. 7D is a schematic illustration of yet another
embodiment of the separation system of FIG. 7.
[0028] FIG. 7E is a schematic illustration of a further embodiment
of the separation system of FIG. 7 and can include a single bed
pressure swing adsorption system with a buffer tank.
[0029] FIG. 7F is a schematic illustration of another embodiment of
the separation system of FIG. 7 and can include a combination of
adsorption and/or membrane separation units.
[0030] FIG. 7G is a schematic illustration of yet another
embodiment of the separation system of FIG. 7 and can include
multiple membrane separation units.
[0031] FIG. 7H is a schematic illustration of a further embodiment
of the separation system of FIG. 7.
[0032] FIG. 8 is a schematic diagram of another embodiment in which
air or exhaust from an engine is subjected to a separation process
to produce inert rich gas therefrom.
[0033] FIG. 9A is a top plan view of a mobile inert gas separation
system mounted on a trailer, which can include any of the above
described separation systems, the trailer being configured to be
towed over the road by a towing vehicle.
[0034] FIG. 9B is a side elevational view of the system shown in
FIG. 9A.
[0035] FIG. 10 is a schematic diagram of an exemplary feed air
compressor that can be used with any of the above illustrated inert
gas separation systems.
[0036] FIG. 11 is a schematic illustration of an exemplary filter
assembly that can be used with any of the above illustrated inert
gas separation systems.
[0037] FIG. 12 is a top plan view of the filter system illustrated
in FIG. 11.
[0038] FIG. 13 is a front elevational view of the filter assembly
illustrated in FIG. 12.
[0039] FIG. 14 is a side elevational view of the filter assembly
illustrated in FIG. 12.
[0040] FIG. 15 is a top plan view of an exemplary carbon tower that
can be used with any of the above-identified inert gas separation
systems.
[0041] FIG. 16 is a front elevational view of the carbon tower of
FIG. 15.
[0042] FIG. 17 is a side elevational view of the carbon tower of
FIG. 15.
[0043] FIG. 18 is a bottom plan view of the carbon tower of FIG.
15.
[0044] FIG. 19 is a schematic illustration of an exemplary membrane
separation unit that can be used with any of the above-illustrated
inert gas separation systems.
[0045] FIG. 20 is a top plan view of an exemplary embodiment of the
membrane unit of FIG. 19.
[0046] FIG. 21 is a right side elevational view of the membrane
unit illustrated in FIG. 20.
[0047] FIG. 22 is a rear elevational view of the membrane unit
illustrated in FIG. 20.
[0048] FIG. 23 is a left side elevational view of the membrane unit
illustrated in FIG. 20.
[0049] FIG. 24 is a schematic diagram of an exemplary booster
compressor that can be used with any of the above-illustrated inert
gas separation systems.
[0050] FIG. 25 is a schematic diagram of an exemplary auxiliary
heater system that can be used with any of the above-illustrated
inert gas separation systems.
[0051] FIG. 26 is a schematic electrical diagram that can be used
to operate the compressor of FIG. 10.
[0052] FIG. 27 is a schematic electrical diagram that can be used
to operate the booster compressor of FIG. 24.
[0053] FIG. 28 is a schematic electrical diagram of a lighting
system that can be used with any of the above-illustrated inert gas
separation systems.
[0054] FIG. 29 is a schematic electrical diagram of a circuit that
can be used to operate a portion of the heater system of FIG.
25.
[0055] FIG. 30 is a schematic electrical diagram of a circuit that
can be used to operate a portion of the heater system of FIG.
25.
[0056] FIG. 31 includes a legend defining the symbols used in the
figures contained herein.
[0057] FIG. 32 is an illustration of another modification of the
inert gas separation systems illustrated above, which can utilize
any of the above-identified components and systems, and which
includes a power take-off (PTO) device driven by an engine used for
moving the system and which can be used to
[0058] FIG. 33 is a schematic diagram illustrating a control panel
with a touch screen that can be used for remotely controlling any
of the above-illustrated mobile systems.
[0059] FIG. 34 is a schematic electrical diagram of a power supply
system that can be used with any of the above-illustrated mobile
systems.
[0060] FIG. 35 is a schematic diagram of an optional display
arrangement that can be used with any of the above-illustrated
mobile systems.
[0061] FIG. 36 is a schematic diagram of control devices that can
be used with any of the above-illustrated mobile systems.
[0062] FIG. 37 is a schematic diagram of control devices that can
be used with any of the above-illustrated mobile systems.
[0063] FIG. 38 is a schematic illustration of an electronic control
system that can be used with any of the above illustrated mobile
systems.
[0064] FIG. 39 is a perspective view of a control panel that can be
used with any of the above illustrated mobile systems.
[0065] FIG. 40 is a nitrogen generating unit screen of a graphical
user interface that can be used in conjunction with a control panel
of FIG. 39.
[0066] FIG. 41 is a feed air compressor screen of a graphical user
interface that can be used in conjunction with a control panel of
FIG. 39.
[0067] FIG. 42 is a membrane section screen of a graphical user
interface that can be used in conjunction with a control panel of
FIG. 39.
[0068] FIG. 43 is a booster compressor screen of a graphical user
interface that can be used in conjunction with a control panel of
FIG. 39.
[0069] FIG. 44 is another screen of a graphical user interface that
can be used in conjunction with a control panel of FIG. 39.
[0070] FIG. 45 is a system configuration screen of a graphical user
interface that can be used with a control panel of FIG. 39.
[0071] FIG. 46 is a temperature control screen of a graphical user
interface that can be used in conjunction with a control panel of
FIG. 39.
[0072] FIG. 47 is a temperature tuning screen of a graphical user
interface that can be used in conjunction with a control panel of
FIG. 39.
[0073] FIG. 48 is a device selection screen of a graphical user
interface that can be used in conjunction with a control panel of
FIG. 39.
[0074] FIG. 49 is a device setting screen of a graphical user
interface that can be used in conjunction with a control panel of
FIG. 39.
[0075] FIG. 50 is an oxygen sensor calibration screen of a
graphical user interface that can be used in conjunction with a
control panel of FIG. 39.
[0076] FIG. 51 is a flow device calibration screen of a graphical
user interface that can be used in conjunction with the control
panel of FIG. 39.
[0077] FIG. 52 is a pressure device calibration screen of a
graphical user interface that can be used in conjunction with the
control panel of FIG. 39.
[0078] FIG. 53 is a temperature device calibration screen of a
graphical user interface that can be used in conjunction with the
control panel of FIG. 39.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0079] The present embodiments generally relate to an improved
system and methods for producing inert gases on a mobile platform.
The systems and methods for producing inert gases are generally
described in conjunction with the production of inert gas, such as
nitrogen gas (N.sub.2), for use during a drilling operation because
this is an application in which the present systems and methods
have particular utility. Additionally, the systems and methods can
be used to produce inert gas having different levels of purity.
Those of ordinary skill in the relevant art can readily appreciate
that the present systems and methods described herein can also have
utility in a wide variety of other settings, for example, but
without limitation, offshore drilling rigs as discussed in greater
detail below.
[0080] FIG. 1 is a schematic view of a typical drill stem
arrangement 18 showing the delivery of an inert rich gas to a
downhole drilling region 19. Generally, inert rich gas flows down
the drill stem arrangement 18 until it reaches a drill stem
assembly 20 which is typically connected in lengths known as "pipe
stands". The drill stem assembly 20 can be fed through the well
head assembly (identified generally by numeral 22) which may
contain a series of pipe rams, vents, and choke lines. The inert
rich gas is exhausted through an outlet 24 which is connected to a
blooey line.
[0081] For non-drilling applications, the drill stem assembly 20
may be removed and the inert rich gas can be pumped into the
downhole region through the pathway 26.
[0082] The surface installation may optionally include an injector
manifold (not shown) for injecting chemicals, such as surfactants
and special foaming agents, into the inert rich gas feed stream, to
help dissolve mud rings formed during drilling or to provide a low
density, low velocity circulation medium of stiff and stable foam
chemicals to cause minimum disturbance to unstable or
unconsolidated formations.
[0083] Extending below the surface of the ground into the downhole
region is the drill stem arrangement 18 which provides a pathway
for the flow of pressurized inert rich gas to the drilling region.
There is also provided a second pathway for the flow of nitrogen
gas and the drill cuttings out of the downhole region and away from
the drilling operation.
[0084] With continued reference to FIG. 1, the drill stem
arrangement includes an outlet or surface pipe 24 and a casing 32.
The drill stem assembly 20 extends concentrically with and spaced
apart from the surface pipe 24 and production casing 32 so as to
define a pathway 42 for the return of inert rich gas and the drill
cuttings. The center of the drill stem assembly 20 provides a
pathway 26 for the flow of inert rich gas to the drilling region.
At the lower end 75 of the drill stem arrangement 18, in vicinity
of the lower drilling region 34, is a conventional tool joint 35, a
drill collar 36 and a drill bit 38.
[0085] The inert rich gas (e.g., nitrogen rich gas) is typically
pressurized by a compressor and is then delivered to the drill stem
assembly 20. Because the inert rich gas is under pressure, it can
swirl around the drilling region 34 with sufficient force and
velocity to carry the drill cuttings upwards into the pathway 42.
The drill cutting containing stream then exits the outlet 24 of the
surface installation equipment where it is carried to a blooey line
and eventually discarded into a collection facility, typically at a
location remote from the actual drilling site.
[0086] The inert rich gas described above for removing drilling
cuttings can also be injected into the drilling fluid to reduce the
density thereof. This provides greater control over the drilling
fluid and is particularly adapted for "underbalanced" drilling
where the pressure of the drilling fluid is reduced to a level
below the formation pressure exerted by the oil and/or gas
formation. The inert rich gas can be provided to the drilling fluid
in the following exemplary but non-limiting manner.
[0087] With continued reference to FIG. 1, the inert rich gas can
be injected into a drilling fluid through an assembly shown in FIG.
1 absent the drill stem assembly 20. In one embodiment, the inert
rich gas is pumped through the pathway 26 which can be in the form
of linear pipe strings or continuous coiled tubing known as a
"drill string". Alternatively, the inert rich gas can be pumped
into the annular space 42 between the drill string or pathway 26
and the casing 32 inserted into the well. In this embodiment a
drill string can be inserted directly into the annular space 42 to
provide the inert rich gas directly therein. As such, the inert
rich gas can be used to modify the flow properties and weight
distribution of the cement used to secure the casings within the
well.
[0088] With reference to FIGS. 2, 3 and 4, a well 44 is supported
by tubular casings including an intermediate casing 88, a surface
casing 50, and a conductor casing 48. The conductor casing 48 is
set at the surface to isolate soft topsoil from the drill bit so as
to prevent drilling mud from eroding the top section of the well
bore.
[0089] The surface casing 50 also extends from the surface of the
well and is run deep enough to prevent any freshwater resources
from entering the well bore. In addition to protecting the fresh
water, the surface casing 50 prevents the well bore from caving in
and is an initial attachment for the blow-out-prevention (BOP)
equipment. Typical lengths of the surface casing 50 are in the
range of about 200 to 2500 ft.
[0090] The intermediate casing 88 protects the hole from formations
which may prove troublesome before the target formation is
encountered. The casing 88 can be intermediate in length, i.e.,
longer than the surface casing 50, but shorter than the final
string of casing (production casing) 32.
[0091] The production casing (oil string or long string) extends
from the bottom of the hole back to the surface. It isolates the
prospective formation from all other formations and provides a
conduit through which reserves can be recovered.
[0092] The diameter of the various casings 48, 50, 88 decreases as
the depth of the casing into the well 44 increases. Accordingly,
the intermediate casing 88 extends the furthest into the well 44.
The intermediate casing 88 is typically filled with a drilling
fluid 58 such as drilling mud.
[0093] The process of securing the casing within the well using a
cement-like material is illustrated in FIGS. 3 and 4. With
reference to FIG. 3, a well 44 contains a casing 60 which is
initially filled with a drilling fluid 58 such as drilling mud or a
drilling mud modified with a nitrogen rich gas. A wiper plug 62 is
inserted into the casing 60 and urged downward to force the
drilling fluid out of the bottom opening 65 and up along the
annular space 64 between the walls 66 defining the well bore and
the casing 60. The drilling fluid proceeds upwardly through the
annular space 64 and out of the opening 70 at the top of the well
44.
[0094] While the drilling fluid is being evacuated a cement-like
material in the form of a slurry is loaded into the casing 60. A
second wiper plug 66 is then urged downwardly as shown in FIG. 4 to
force the cement out of the bottom opening 65 until the annular
space 64 is filled. Excess cement escapes out of the opening 70 of
the well.
[0095] An inert rich gas, preferably nitrogen gas, which can be
produced as described below, can be used to reduce the density of
the cement in a manner similar to that described for the drilling
fluid. The inert rich gas can be injected into the casing while the
cement is being added therein. The injection of the inert rich gas
into the cement modifies the density and flow characteristics of
the cement while the cement is being positioned in the well.
[0096] The inert rich gas is injected into the casing through a
drill string of the type described in connection with FIG. 1 with
the drill stem assembly 20 removed. The rate of injection and the
precise composition of the inert rich gas is controlled by a
compressor.
[0097] The inert rich gas can be used to improve the buoyancy of
the casings so as to minimize the effects of friction as the
casings are inserted into the well. This is particularly apparent
when casings are inserted into horizontal sections in the downhole
region. In horizontal sections, the weight of the casing causes it
to drag along the bottom surface of the wellbore. In extreme cases
the casing may become wedged in the wellbore and not be able to be
advanced as far into the downhole region as desirable. Introducing
an inert rich gas into the interior of the casing will increase the
buoyancy of the casing, allowing it to float in the mud or drilling
fluid surrounding the casing.
[0098] With continued reference to FIG. 2, there is shown a casing
assembly including a tubular member or liner 68 which is designed
to enter a horizontal section 70 of the well 44. The liner 68 is
any length of casing that does not extend to the surface of the
well.
[0099] The liner 68 includes an upper section 72 which contains a
drilling fluid and a lower section 73. The upper and lower sections
are separated by an inflatable packer 74. The lower section 73 is
charged with the inert rich gas which makes it lighter and more
buoyant than the upper section 72 which is filled with mud. The
lower section 73 may therefore move easily into the horizontal
section 70 of the well 44.
[0100] After the completion of drilling in the downhole region,
inert rich gas can be used to improve well performance and maximize
output of gas and/or oil from the reservoir. Quite often well
production declines because of the presence of fluids, such as
water, excess drilling mud and the like in the downhole region. The
inert rich gas can be used to clean out the well by displacing the
heavier fluids that collect therein. Removal of the heavier fluids
will regenerate the flow of gas and/or oil from the reservoir if
there is sufficient formation pressure within the reservoir. The
inert rich gas can be used to provide an additional boost for
lifting the gas and/or oil from the downhole region to a collection
area. In this case the inert rich gas is pumped down into the
downhole region within the casing under sufficient pressure so that
the gas and/or oil entering the downhole region from the reservoir
is lifted upwardly and out of the well.
[0101] With reference to FIG. 5, there is shown an assembly
particularly suited for injecting an inert rich gas into the gas
and/or oil within the downhole region to facilitate delivery
thereof upwardly through the well for collection. Such a system is
applicable to downholes having reduced formation pressure. As a
result the gas and/or oil has difficulty entering the downhole from
the reservoir.
[0102] The inert rich gas can be injected into the annulus 80
between the casing 84 and a tubing 86. The inert rich gas is
metered into the tubing 86 through a valve assembly 88. The tubing
86 has an opening 90 enabling gas and/or oil from the downhole
region to enter and rise up to the surface of the well. The
injection of the inert rich gas from the valve assembly 88 into the
tubing 86 assists the gas and/or oil by providing buoyancy to the
flow upwardly to the above ground collection area 94. This process
is commonly referred to as artificial gas lift.
[0103] In another application for inert rich gas, the nitrogen rich
gas is used to stimulate the well in the downhole region to enhance
gas and/or recovery. More specifically, the walls of the wellbore
in the downhole region characteristically have cracks or fissures
through which the gas and/or oil emerges from the reservoir. As the
pressure in the reservoir decreases, the fissures begin to close
thereby lowering production. The most common form of stimulating
the downhole region is by acidizing or fracturing the wellbore. The
inert rich gas can be used as a carrier for the acid to treat the
wellbore. The inert rich gas expands the volume of the acid,
retards the reaction rate of the acid resulting in deeper
penetration, and permits faster cleanup because there is less
liquid to be displaced by the high energy inert rich gas.
[0104] Cracking of the wellbore in the downhole region can be
performed by pumping a fluid such as acid, oil, water, or foam into
a formation at a rate that is faster than what the existing pore
structure will accept. At sufficiently high pressures, the
formation will fracture, increasing the permeability of the
downhole. When the stimulation procedure is completed, the pressure
in the formation will dissipate, and the fracture will eventually
close. Sand and/or glass beads or other so-called "poppants" may be
injected into the formation and embedded in the fractures to keep
the fractures open. The inert rich gas may be used as a carrier gas
to carry the poppants to the wellbore.
[0105] It is well established that the pressure in a reservoir
(formation pressure) provides for the flow of gas and/or oil to the
downhole region. As the reserves of gas and/or oil become depleted,
the formation pressure decreases and the flow gradually decreases
toward the well. Eventually the flow will decrease to a point where
even well stimulation techniques as previously described will be
insufficient to maintain an acceptable productivity of the well.
Despite the reduced formation pressure, nonetheless, the reservoir
may still contain significant amounts of gas and/or oil
reserves.
[0106] In addition, gas-condensate reservoirs contain gas reserves
which tend to condense as a liquid when the formation pressure
decreases below acceptable levels. The condensed gas is very
difficult to recover.
[0107] The lack of formation pressure in a reservoir can be
remedied by injecting an inert rich gas directly into the
reservoir. As illustrated highly schematically in FIG. 6, an inert
gas generation system is shown generally by numeral 210. The
assembly is constructed above a gas and/or oil reservoir 102. Inert
rich gas is pumped down the well, often called an injector well
44a, through a tubing 104 to exert pressure on the reserves in the
direction of the arrow. The increased pressure on the gas and/or
oil causes the same to flow to a producing formation and up a
producing well 44b through a tubing 106 into an above ground
collection vessel 108.
[0108] The flow rate of inert rich gas to the drilling region of an
oil and/or gas well or a geothermal well can vary over a wide range
depending on the size of the downhole, the depth of the well, the
rate of drilling, the size of the drilling pipe, and the makeup of
the geologic formation through which the well must be drilled. Some
typical drilling operations require the production of 1,500 to
3,000 standard cubic feet per minute (scfm) of nitrogen gas from
the inert gas separation system 210; however, other flow rates can
also be used. The inert rich gas can be pressurized up to a
pressure of about 1,500 to 2,000 psig before being passed to the
drilling region, however, other pressures can also be used.
[0109] An average drilling operation can take about five days to
two weeks, although difficult geologic formations may require
several months of drilling. The inert rich gas delivery system is
designed for continuous operation and all of the inert rich gas is
generated on-site without the need for external nitrogen
replenishment required for cryogenically produced liquid nitrogen
delivery systems.
[0110] In a typical underbalanced drilling operation, 500 to 800
scfm (standard cubic feet per minute) of an inert rich gas is
commingled with drilling mud to reduce the hydrostatic weight of
the drilling fluid in the downhole region of a well. This reduces
or prevents an overbalanced condition where drilling fluid enters
the formation, or mud circulation is lost altogether. Carefully
adjusting the weight of the drilling fluid will keep the formation
underbalanced, resulting in a net inflow of gas and/or oil into the
well.
[0111] If a drill string becomes stuck due to high differential
pressure caused by combined hydrostatic and well pressure
conditions, an inert rich gas at 1500-3000 scfm at pressures of
1000-2000 psig can be injected down the drill string to force the
fluid up the annulus to the surface. The reduced weight and
pressure will help free the stuck pipe. In this case, the inert
rich gas is used as a displacement gas.
[0112] A naturally producing reservoir loses pressure (depletes)
over time with a resulting loss in recoverable oil and/or gas
reserves. Injection of nitrogen at 1500 scfm or greater at various
locations or injection sites will keep the reservoir pressurized to
extend its production life. In gas condensate reservoirs, the
pressure is kept high enough to prevent gas condensation or
liquefaction, which is difficult to remove once liquefied.
[0113] The inert rich gas can be introduced into the producing
wells by means of special valves in the production casing
positioned in the downhole region of the well. The lifting action
of the inert rich gas is one form of artificial gas lift as shown
best in FIG. 5.
[0114] With reference to FIG. 6A, the mobile inert gas separation
system 200 can include a propulsion device 206 and a suspension
device 208 supporting an inert gas separation system 210.
[0115] The propulsion device 206 can be in the form of any type of
propulsion device, including, for example, but without limitation,
a truck designed for towing on highway or off-road. The suspension
device 208 can be in the form of a trailer configured to be towed
by the propulsion device 206. Optionally, the propulsion device 206
and the suspension device 208 can be integrally formed in a rigid
frame, fixed wheel base truck. However, these are merely examples
of propulsion devices 206 and suspension devices 208 that can be
used to allow the inert gas separation system 210 to be mobile.
Other arrangements can also be used.
[0116] FIG. 7 illustrates one embodiment of an inert gas generation
system 210 that can provide a supply of inert gas. The system 210
can produce inert gas of suitable quality for use, for example, in
drilling operations as described above. The inert gas generation
system 210 preferably includes a flow source 212, a conditioning
system 214, and an output 216 of the conditioning system 214.
[0117] The flow source 212 provides an output of fluid to the
conditioning system 214. The flow source 212 can be configured to
output any type of fluid having a reduced amount of oxygen and an
inert portion. In the illustrated embodiment, the output of the
flow source 212 is exhaust gas from a combustion process. However,
as noted above, output of the flow source 212 can be compressed
atmospheric air.
[0118] An output of the flow source 212 is connected to the
conditioning system 214. The conditioning system 214 can be
configured to treat and/or condition the output to achieve desired
flow characteristics of the flow passing out of output 216. For
example, the conditioning system 214 can be configured to convert
the output of the source 212 into a fluid with suitable pressure,
purity, temperature, volumetric flow rate, and/or any other
desirable characteristic depending on, for example, the end use of
the output flow.
[0119] In one non-limiting embodiment, the inert gas generation
system 210 is configured to produce a flow that comprises an inert
gas. The inert gas can be a highly pure inert gas, such as Nitrogen
gas. In one embodiment, the inert gas comprises mostly Nitrogen gas
but can include other substances, such as Oxygen and
particulates.
[0120] In the illustrated embodiment, the flow source 212 can
comprise an air/fuel engine 220. The air/fuel engine 220 can
comprise any type of air/fuel combustion engine, including
open-system combustion engines such as, but without limitation,
turbine engines, as well as internal combustion engines, including,
but without limitation diesel, gasoline, four-stroke, two-stroke,
rotary engine, and the like. In some embodiments, the air/fuel
engine 220 can be configured to provide propulsion power for
transporting the entire mobile separation system 200.
[0121] In an exemplary but non-limiting embodiment, the engine 220
is a diesel engine. The engine 220 can be normally aspirated,
turbo-charged, super-charged, and the like. The construction and
operation of such engines are well known in the art. Thus, a
further description of the construction and operation of the engine
220 is not repeated herein.
[0122] In an exemplary but non-limiting embodiment, the engine 220
is configured to produce an output of about 400-650 horsepower
(hp). In another exemplary but non-limiting embodiment, the engine
220 is configured to produce an output of about 550 hp. Optionally,
the flow source 212 can comprise a plurality of similar or
different engines 220. In one exemplary but non-limiting
embodiment, the flow source 212 comprises one or more diesel
engines and/or one or more gasoline engines. In another embodiment,
the flow source 212 comprises a plurality of diesel engines.
[0123] The output from the engine 220 can contain various products
of combustion. The exhaust produced by the engine 220 can include
gases, liquids, and particles. For example, the output can comprise
gases such as argon, hydrogen (H.sub.2), nitrogen (N.sub.2), oxides
of Nitrogen (NO.sub.x), carbon oxide (e.g., carbon monoxide (CO)
and carbon dioxide (CO.sub.2)), hydrocarbons, and/or other gases.
The output can also comprise fluid such as water (H.sub.2O) and
oil. The output can also comprise particles such as diesel
particulate matter, if the engine 220 is a diesel engine. Of
course, the output of the flow source 212 will have different
components depending on the type of flow source 212 that is
employed.
[0124] The engine 220 can draw in ambient air through an air intake
221 and can produce exhaust containing both inert and non-inert
gas. Preferably, the volume percentage of the inert gas output from
the engine 220 is generally greater than the volume percentage of
the inert gas typically present in ambient air.
[0125] In some embodiments, the volume percentage of the inert rich
gas of the exhaust fluid produced by the engine 220 is at least 5%
greater than the volume percentage of inert gas typically present
in ambient air. In yet another embodiment, the volume percentage of
the inert rich gas of the exhaust fluid produced by the engine 220
is at least 10% greater than the volume percentage of inert gas
typically present in ambient air. In some embodiments, the
proportion of inert gas in the exhaust of the engine 220 can be
increased by increasing the power output from the engine 220.
[0126] For example, diesel engines do not have a throttle valve.
Thus, when a diesel engine is operating at a power output level
that is below full power, the amount of fuel burned in the engine
is not sufficient to burn all of the air in the engine. Thus, fuel
is burned in a "lean" mixture, i.e., non-stoichiometric. Thus, the
exhaust gas discharged from the engine 220 contains some oxygen.
However, when the power output of a diesel engine is raised, more
fuel is injected, and thus, more oxygen is "burned", thereby
reducing the oxygen content of the exhaust. Thus, a further
advantage is produced where the engine 220 used is sized such that
during normal operation, the engine 220 is running under an
elevated power output. For example, if the engine 220 is rated at
about 550 horsepower and the engine is operated at about 225
horsepower, the engine 220 will burn a substantial portion of the
oxygen in the ambient air drawn into the engine 220. Further
advantages are achieved where the engine 220 is operated at near
maximum power. For example, if the engine 220 is operated at about
450 horsepower, the engine will burn nearly all of the oxygen
present in the air. One of ordinary skill in the art recognizes
that gasoline-burning engines operate under different air/fuel
principles, and thus, the proportion of oxygen present in
gasoline-powered engines does not vary substantially with power
output.
[0127] Normally, exhaust gas produced by the engine 220 will
contain less oxygen than ambient air. In one-embodiment, the
exhaust gas can contains less than about 10% by volume of oxygen
gas, depending on the air fuel ratio of a mixture combusted therein
and operating load of the engine 220. As noted above, as the fuel
injection rate of a diesel engine is increased, more oxygen is
consumed, and thus, the oxygen content of the exhaust gas is
similarly decreased. Preferably, the exhaust gas from the engine
220 comprises less than about 7% by volume oxygen. In another
embodiment, the exhaust gas from the engine 220 contains less than
about 5% by volume of oxygen gas. In another embodiment, the
exhaust gas from the engine 220 comprises less than about 3% by
volume of oxygen gas.
[0128] The low levels of oxygen gas contained in the exhaust gas
can increase the inert gas purity of the gas discharged from the
conditioning system output 216 of the conditioning system 214.
Additionally, the conditioning system 214 can produce high purity
inert gas even though the working pressure of the conditioning
system 214 is very low. It is contemplated the type of engine 220
employed and the power output of the engine 220 can be varied by
one of ordinary skill in the art to achieve the desired purity of
the gas outputted from the engine 220. The operating conditions of
the engine can also be controlled so as to produce the desired flow
characteristics (e.g., volumetric flow rate, pressure, purity, and
the like).
[0129] For example, in embodiments where the engine 220 is a diesel
engine, the volumetric flow rate of exhaust gases out of the engine
220 can be controlled by controlling the speed of the engine 220.
This is because diesel engines do not operate with a "throttle
valve." Rather, diesel engines always displace the same volume of
gas regardless of the power output of the engine 220. For example,
a 13 liter engine (wherein 13 liters refers to the total volume
swept by the pistons of the cylinders during operation) displaces
about 13 liters of air for each two revolutions of the crank shaft
(where the engine 220 is a 4-stroke engine). As noted above, the
power output from the engine 220 depends on the amount of fuel
injected into the combustion chambers of the engine.
[0130] During operation, diesel engines can operate over a range of
different engine speeds. Additionally, diesel engines generally can
output a significant amount of power or torque over a range of
different speeds. Thus, in some applications, it may be desirable
to set the engine to operate at a fixed speed and allow the engine
controller to control fuel injection to maintain the speed of the
engine by varying the power output. Thus, if it is desired to cause
the engine 220 to output a relatively lower volumetric flow rate of
exhaust gas, the engine 220 can be set to operate between idle
speed and low engine speeds, for example, between 500 and 1,200
rpm. If higher volumetric flow rates are desired, the engine 220
can be set to operate at speeds above 1,200 rpm. However, other
techniques can also be used to vary the volumetric flow rate of
exhaust gas out of the engine 220.
[0131] An exhaust conduit 226 connects the source 212 with the
conditioning system 214. In the illustrated embodiment, the exhaust
conduit 226 connects the engine 220 to a mixing plenum 228 of the
conditioning system 214. The output of the engine 220 is exhaust
flow or fluid that is passed through the exhaust conduit 226 and is
fed into the mixing plenum 228.
[0132] Optionally, the inert gas generation system 210 can include
a temperature control system 236 for controlling the temperature of
the exhaust fluid before the exhaust fluid enters the mixing plenum
228. For example, the temperature control system 236 can include a
heat exchanger configured to maintain the temperature of the
exhaust fluid at a desired temperature.
[0133] In the some embodiments, the temperature control system 236
can increase or decrease the temperature of the exhaust fluid as it
flows down the exhaust conduit 226. By removing heat from the
exhaust fluid flowing through the exhaust conduit 226, a further
advantage is provided in preventing undesirable effects, such as
overheating, of downstream devices. Although not illustrated, the
temperature control system 236 can include temperature sensors,
pressure sensors, flow meters, or the like.
[0134] Preferably, the mixing plenum 228 is configured and sized to
receive a continuous flow of exhaust fluid from the exhaust conduit
226. However, the mixing plenum 228 can be configured and sized to
receive an intermittent flow or any type of flow of exhaust fluid.
Additionally, the mixing plenum 228 can be adapted to receive the
exhaust flow at various volumetric flow rates.
[0135] In an exemplary but non-limiting embodiment, the mixing
plenum 228 includes a enlarged chamber 229. The chamber 229 can
comprise a plurality of channels or tubes that are configured to
mix the exhaust fluid with one or more other gases. For example, in
some embodiments, the mixing plenum 228 can include the air intake
230 that draws in ambient air surrounding the mixing plenum 228
into the channels within the mixing plenum 228. The mixing plenum
228 can combine and mix the ambient air with the exhaust fluid to
output a generally homogeneous or heterogeneous fluid to downstream
sections of the conditioning system 214. In other embodiments, the
mixing chamber is substantially sealed from ambient air.
[0136] Optionally, the mixing plenum 228 can have a controller 232
configured to selectively determine the mixture and content of the
output flow from the mixing plenum. For example, the controller 232
can include a device (e.g., a motor) configured to agitate and mix
the fluids contained within mixing plenum 228.
[0137] Optionally, a feedback device 240 can be configured to
control the total level of inert and non-inert gases within the
mixing plenum 228. For example, the feedback device 240 can include
a controller 242 for controlling the proportion of exhaust fluid
from the exhaust conduit 226 to the amount of ambient air from the
air intake 230 contained within the mixing plenum 228. In some
embodiments, the feedback device 240 can be configured to reduce
the amount of air flowing into the air intake 230 so as to increase
the purity of the downstream inert gas, described in greater detail
below. The feedback device 240 can also be configured to increase
the amount of ambient air flowing into the air intake 230 and into
the mixing plenum 228 so as to reduce the purity of the downstream
inert gas. Thus, the feedback device 240 can selectively increase
and/or decrease the content and purity of the downstream fluid in
the conditioning system 214.
[0138] Although not illustrated, the feedback device 240 can
include one or more sensors configured to detect, for example, the
level of the constituents within the mixing plenum 228 and/or
within the exhaust conduit 226, the flow parameters (e.g.,
temperature, flow rate, pressure) of the exhaust fluid passing
through the exhaust conduit 226, and the like. The feedback device
240 can be an open or closed loop system for controlling the flow
of substances passing through the conditioning system 214.
[0139] For example, the feedback device 240 can be an open system
that commands the temperature control system 236 wherein an
operator can determine and set the temperature of the exhaust fluid
fed into the mixing plenum 228. In another embodiment, the feedback
device 240 can be a closed loop system and be configured to command
the temperature control system 236 to dynamically change the
temperature of the fluid passing through the conditioning system
214 depending on, for example, the temperature of the fluid passing
out of the conditioning system output 216.
[0140] Optionally, the system 210 can include a back pressure
control device 233 configured to control a back pressure in the
mixing plenum 228. For example, the back pressure control device
233 can be a throttle device having an orifice and a valve, such as
a butterfly-type valve, or any other kind of valve, for metering
the flow rate out of the mixing plenum 228 into the conduit 244.
This restriction device 233 can also be used to control a pressure
of the gases discharged from the mixing plenum 228 into the conduit
244. Optionally, an electronic controller (not shown) can be
incorporated into the device 233 to allow for electronic control of
the back pressure generated by the device 233
[0141] Additionally, the device 233 can also be used to affect the
oxygen concentration of the exhaust gases discharged from the
engine 220. For example, as is well known in the art, as a back
pressure in the exhaust system of an engine, such as the engine
220, is raised, the load on the engine increases. Thus, by
increasing the restriction or the back pressure in the exhaust
system of the engine 220, the load on the engine will increase. If
the engine is set to operate at a constant speed, then the engine
controller will increase the amount of fuel injected into the
combustion chambers of the engine and thereby combust more of the
oxygen of the air flowing into the engine 220. Thus, the oxygen
content of the exhaust gas leaving the engine 220 will be
lower.
[0142] Optionally, gas analysis can be performed on the fluid from
the source 212 to ensure the gas compositions are within desired
levels. Such an analysis can be incorporated into a process
controller (not shown) integrated with the conditioning system 214,
or any other part of the system 210. In some embodiments, the
process controller is integrated with the controller 242. However,
other components of the conditioning system 214 can have one or
more process controllers for determining the composition of the
fluid passing through the system 214 to control the composition of
the output gas passing out of the conditioning system output
216.
[0143] The conditioning system 214 can also include a plenum
conduit 244 that extends from the mixing plenum 228 to a compressor
246. Thus, fluid from the mixing plenum 228 can pass through the
plenum conduit 244 and into the compressor 246.
[0144] In one non-limiting embodiment, the compressor 246 is
configured to draw fluid from the mixing plenum 228 and increase
the pressure thereof. For example, the compressor 246 can be
configured to raise the pressure of the fluid from the mixing
plenum 228 to pressures from about 100 psig to about 600 psig.
[0145] The compressor 246 can be any type of compressor.
Preferably, the compressor 246 is a rotary screw type compressor.
However, the compressor 246 can be a pump with fixed or variable
displacement that causes an increased downstream fluid pressure. It
is contemplated that one of ordinary skill in the art can determine
the type of compressor to achieve the desired pressure increase of
the fluid. For example, in one embodiment the compressor 246 is a
booster compressor. Although not illustrated, the inert gas
generation system 210 can have a plurality of compressors
configured to draw fluid from the mixing plenum.
[0146] The compression process performed by the compressor 246 can
be used to remove constituents from the exhaust fluid it receives
from the plenum conduit 244. For example, the mixing plenum 228 can
feed exhaust fluid that comprises water into the plenum conduit
244. The plenum conduit 244 then delivers the fluid to the
compressor 246. The compression process of the compressor 246 can
remove an amount, preferably a significant amount, of water from
the fluid. In one exemplary non-limiting embodiment, a water knock
out vessel is included in the compressor 246 to collect water
removed from the fluid. Additionally, a coalescent filter (not
shown) can be provided to remove additional entrained water and oil
carryover that may be present in the output fluid.
[0147] The conditioning system 214 can also include a compressor
conduit 250 that extends from the compressor 246 to a filtration
unit 251.
[0148] The filtration unit 251 can include one or more devices to
remove components from the fluid delivered by the compressor
conduit 250. In the illustrated embodiment, the filtration unit 251
includes a filtration system 252 and a particulate filter 260. In
one non-limiting exemplary embodiment, fluid delivered from the
compressor 246 can pass through the compressor conduit 250 and into
the filtration unit 251.
[0149] Optionally, the conditioning system 214 can also include a
temperature control system 256 configured to adjust the temperature
of fluid passing through the compressor conduit 250. Preferably,
the temperature control system 256 is configured to lower the
temperature of the fluid proceeding along the compressor conduit
250 to a desired temperature.
[0150] For example, the temperature control system 256 and the
compressor 246 can work in combination to adjust the temperature of
the fluid passing therethrough to a desired temperature to prevent,
for example, overheating of downstream components (e.g., the
filtration unit 251). In at least one embodiment, the compressor
246 can provide fluid to compressor conduit 250 at a predetermined
pressure. The temperature control system 256 can be configured to
increase or decrease the temperature of the fluid to adjust the
pressure of the fluid. For example, the temperature control system
256 can reduce the temperature of the fluid passing through the
compressor conduit 250 to reduce the pressure of the fluid
delivered to the filtration unit 251. Alternatively, the
temperature control system 256 can increase the temperature of the
fluid passing through the compressor conduit 250 to increase the
pressure of the fluid delivered to the filtration unit 251.
[0151] The temperature control system 256 can be different or
similar to the temperature control system 236. In at least one
embodiment, the temperature control system 256 is a heat exchanger
that can rapidly change the temperature of the fluid that passes
along the compressor conduit 250. Similar to the temperature
control system 236, the temperature control system 256 can be part
of an open or closed loop system.
[0152] The filtration unit 251 can be configured to capture and
remove undesirable substances from the exhaust fluid. The
filtration unit 251 can include a filtration system 252 configured
to remove undesired substances that may be present in the exhaust
fluid. For example, the filtration system 252 can be configured to
capture selected gas impurities. In one embodiment, the filtration
system 252 can capture carbon oxides, hydrocarbons, aldehydes,
nitrogen oxides (e.g., typically nitric oxide and a small fraction
of nitrogen dioxide), sulfur dioxide, and/or other particulate that
may be in the exhaust fluid. The filtration system 252 can comprise
one or more absorption/adsorption filters and/or vessels that are
suitable for removing one or more undesirable substances.
Optionally, the filtration system 252 can include a catalytic
converter commonly used in the automotive industry.
[0153] With continued reference to FIG. 7, the filtration unit 251
of the conditioning system 214 can also include a filtration system
conduit 254 that extends from the filtration system 252 to the
particulate filter 260. Such a particulate filter 260 can comprise
of one or more absorption filters and/or vessels. The particulate
filter 260 can be configured to remove particulates that may
undesirably adversely affect, for example, the performance of
downstream components of the conditioning system 214 or purity of
the gas produced by the conditioning system 214. If the engine 220
is a diesel engine, the particulate filter 260 is preferably a
filter that captures and removes diesel particulate matter from the
fluid passing therethrough. In one embodiment, the particulate
filter 260 removes a substantial portion of the particulate matter
from the fluid.
[0154] The system 210 can also include an additional heat exchanger
downstream from the particulate filter 260. The heat exchanger can
be configured to adjust the temperature of the filtered fluid from
the particulate filter 260. Raising the temperature of the upstream
fluid can be beneficial because such heating reduces the likelihood
that any remaining water vapor will condense out and damage
downstream components. Optionally, the additional heat exchanger
can be provided with heat from upstream temperature control systems
(e.g., temperature control systems 236, 256). For example, the
temperature control system 236 can be a heat exchanger that cools
the exhaust fluid produced by the engine 220. The heat removed by
the heat exchanger 236 can be delivered to the additional
downstream heat exchanger. The additional heat exchanger can then
use that energy to heat the filtered fluid preferably at some point
downstream of the filtration unit 251. It is contemplated that at
least one of the temperature control systems can provide energy
(e.g., heat) to another temperature control system or heat
exchanger. One of ordinary skill in the art can determine the type,
location, and configuration of one or more temperature control
systems to control the temperature of the exhaust fluid as
desired.
[0155] The system 210 can also include a particulate conduit 262
which extends from the particulate filter 260 to a separation unit
266.
[0156] With reference to FIGS. 7 and 7A, the conditioning system
214 can also include a device adapted for separating inert
substances from non-inert substances. In the illustrated
embodiment, the conditioning system 214 includes the separation
unit 266. In one embodiment, the separation unit 266 is a membrane
separation unit including a chamber 268 and a separation membrane
270 (shown in FIG. 7A) within the chamber 268. As shown in FIG. 7A,
the membrane separation unit 266 has a membrane 270 that partitions
the chamber 268 into a plurality of chambers.
[0157] In the illustrated embodiment, the membrane 270 divides the
chamber 268 into an inert chamber 276 and a non-inert chamber 278.
Preferably, during operation of the system 210 at least a portion
of the inert chamber 276 contains fluid that comprises mostly inert
gas, and the non-inert chamber 278 contains mostly non-inert gas
that is separated from the exhaust fluid. Additionally, the
separation unit 266 can have an inlet 280 and an outlet 281 that
are located on the same side of the membrane 270. Both the inlet
280 and the outlet 281 can be in fluid communication with the inert
chamber 276. Preferably, the inlet 280 and outlet 281 are in fluid
communication with opposing portions of the inert chamber 276.
[0158] The inert chamber 276 can be sized and configured to define
a flow path between the inlet 280 and the outlet 281. The non-inert
chamber 278 can be sized and configured to define a flow path
between the membrane 270 and the vent 294. Preferably, the vent 294
is located on one side of the membrane 270 and both the inlet 280
and the outlet 281 are located on the other side of the membrane
270.
[0159] The membrane 270 can be configured to allow certain
substances to pass therethrough at a first flow rate and other
substances to pass therethrough at a second flow rate different
than the first flow rate. For example, such membrane separation
units 266 can be provided with a membrane 270 that allows different
gases to pass therethrough at different rates. The effect is that
the retentate gas, i.e., gases that do not permeate through the
membrane 270, remain on the inlet side of the membrane 270 within
the inert chamber 276. These gases proceed along the chamber 276
towards, and eventually pass through, the outlet 281. The permeate
gases, preferably non-inert gas, of the fluid delivered through the
inlet 280 pass through the membrane 270 and through the non-inert
chamber 278 and are discharged out of the vent or outlet 294 into
the atmosphere, or are further sequestered.
[0160] In an exemplary but non-limiting embodiment, the membrane
270 is an elongated generally planar membrane extending across the
chamber 268 and is configured to allow the migration of fluid
(e.g., gas) therethrough. Fluid, preferably comprising gases,
enters the inert chamber 276 through the inlet 280, some gases pass
through the membrane 270 while others do not. In some membrane
separation units 266, the membrane 270 can be configured to allow
non-inert gases (e.g., oxygen) to pass more readily through the
membrane 270 and inert gas (e.g., nitrogen) to pass through the
membrane 270 at a much lower rate. The membrane 270 can thus be
used to separate fluid passing in through the inlet 280 into an
inert gas flow that passes out of the outlet 281 and a non-inert
gas flow that passes through the membrane 270 and out of the vent
294.
[0161] In one embodiment, fluid passing through the inlet 280 and
into the separation unit 266 can include, for example but without
limitation, nitrogen gas, oxygen gas, oxides of carbon, oxides of
nitrogen, and oxide of sulfur, as well as other trace gases. The
membrane 270 can be configured to allow one or more of the
non-inert gases, such as oxygen gas, to pass therethrough at a
relatively higher rate than the rate at which inert gas, such as
nitrogen gas, can pass therethrough. Other gases such as carbon
dioxide, oxides of nitrogen, oxides of sulfur, and other trace
gases may also pass at a higher rate through the membrane 270 than
the rate at which nitrogen gas passes through the membrane 270. The
inert gases are thus captured in the inert chamber 276 and the
non-inert gases pass through the membrane 270 and into the
non-inert chamber 278. The result is that the gas remaining in the
inert chamber 276 has a high concentration of inert gases. Of
course, the concentration of the inert gas in the inert chamber 276
can vary along the inert chamber 276 in the downstream direction.
Preferably, the gas in the inert chamber 276 and proximate to the
outlet 281 comprises substantially inert gas.
[0162] In the present exemplary but non-limiting embodiment, the
fluid within the inert chamber 276 can be largely nitrogen gas and
may include other inert gases. For example, the inert chamber 276
can contain inert gases such as, for example, without limitation,
argon, carbon monoxide, and hydrocarbons. Preferably, most of the
hydrocarbons have been filtered out of the exhaust fluid produced
by the engine 220 by the filtration unit 251. Optionally, the
membrane 270 can be configured to allow water vapor to pass
therethrough at a higher rate than the rate at which nitrogen gas
can pass therethrough. Thus, the separation unit 266 can receive
fluid having water, inert gases, and non-inert gases. The
separation unit 266 can produce a first flow of mostly inert gas
flow and a second flow of non-inert gas and water. The first flow
passes through the inert chamber 276 and out of the outlet 281 and
the second flow passes through the membrane 270 and then through
the non-inert chamber 278 and out of the vent 294.
[0163] FIG. 7B illustrates an embodiment of a membrane that can be
employed by the separation unit 266 to separate fluid. The
components of the system 266 have been identified with the same
reference numerals as those used to identify corresponding
components of the system 210, except that "'" has been used.
[0164] In one exemplary but non-limiting embodiment, the membrane
270' can be a hollow fiber, semi-permeable membrane. A body 302 of
the membrane 270' can allow certain substances to pass therethrough
at a first flow rate and other substances to pass therethrough at a
second flow rate different than the first flow rate. Although not
illustrated, the hollow fiber membrane 270' can be disposed in the
chamber 268 of the unit 266 shown in FIG. 7A. The construction of
this type of membrane separation unit is well-known in the art, and
thus, a further detailed description of the system 266 is not
included herein.
[0165] The hollow fiber membrane 270' can include an inlet 300, the
body 302, a central chamber 310, and an outlet 304. The hollow
fiber membrane 270' can separate the fluid provided by the conduit
262 (FIG. 7) into a purified inert gas flow and a non-inert gas
flow. In some embodiments, with reference to FIG. 7B, fluid passing
through the conduit 262 can pass into the separation unit 266 and
into the inlet 300 of the membrane 270' in the direction indicated
by the arrow 308. The fluid entering the membrane 270' can include
nitrogen gas, oxygen gas, carbon dioxide, oxides of nitrogen, and
oxides of sulfur, as well as other trace gases. As the fluid flows
through the central chamber 310 defined by the body 302, the fluid
is separated into its component gases and the more permeable gases
migrate through the body 302. Preferably, the membrane 270'
separates the fluid it receives into a first stream of mostly inert
fluid that passes through the chamber 310 and out of the outlet 304
and another stream of fluid that passes through the body 302 of the
membrane 270' in the direction indicated by arrows 311. That is, a
stream of inert gases passes through the chamber 310 and out of the
outlet 304. The separation unit 266 then delivers those inert gases
to the conduit 290 (see FIG. 7). The non-inert gases which pass
through the body 302 of the membrane 270' can be directed to the
vent 294 of the unit 266 and discharged into the atmosphere, or
further sequestered.
[0166] Although not illustrated, the separation unit 266 can
include any suitable number of membranes 270'. The membrane
separation 266 may have an increased or reduced number of membranes
270' for an increased or reduced, respectively, separation capacity
of the separation unit 266. For example, the separation unit 266
can include thousands or millions of the hollow fiber
semi-permeable membranes 270' that are bundled or packed together.
The separation unit 266 can therefore have an extremely large
membrane surface area capable of separating non-inert gas from the
fluid passing through the conditioning system 214. Of course, the
length of the membrane 270' can be varied to achieve the desired
membrane surface area and pressure drop across the separation unit
266.
[0167] The separation unit 266 can receive exhaust fluid from the
conduit 262 and remove at least a portion of the non-inert
component of the exhaust fluid. The separation unit 266 can then
output an inert rich gas. In one exemplary embodiment, the
separation unit 266 can produce inert rich gas that comprises at
least 96% by volume of inert gas. In one exemplary embodiment, the
separation unit 266 can produce inert rich gas that comprises about
98% by volume of inert gas. In another embodiment, the inert rich
gas comprises about 99% by volume of inert gas. In yet another
embodiment, the inert rich gas comprises about 99.9% by volume of
inert gas. Advantageously, because the separation unit 266 only has
to remove a low amount of non-inert gas from the exhaust fluid
provided by the conduit 262, the separation unit 266 can produce
highly pure inert rich gas at high volumetric flow rates. The
separation unit 266 can therefore rapidly separate the exhaust flow
into non-inert rich gas and an inert rich flow. In one embodiment,
the separation unit 266 removes less than about 10% by volume of
the fluid and discharges highly pure inert rich gas.
[0168] Optionally, the conditioning system 214 can comprise a
plurality of separation units 266. Each of separation units 266 can
include one or more membranes 270', or membrane 270. Thus, each of
the membrane separation units 266 can comprise one or more similar
or dissimilar membranes. It is contemplated that a plurality of
separation units 266 of the conditioning system 214 can be in a
parallel configuration or in a series configuration. For example, a
plurality of membrane separation units 266 can be in series along
the conditioning system 214 to provide an extremely pure inert
fluid, preferably a gas, out of the conditioning system output 216.
Each of the separation units 266 can increase the purity of the
inert gas passing through the conditioning system 214.
[0169] In one exemplary but non-limiting embodiment of FIG. 7C, the
separation unit 266 is a pressure swing adsorption system (PSA)
that preferably produces a purified inert gas. The PSA 266 may
comprise a plurality of beds for producing inert rich gas.
Preferably, each of the beds includes an adsorption material (e.g.,
carbon molecular sieve or silica gel) adapted to adsorb a non-inert
component at a faster rate than the rate of absorption of inert
components. In one non-limiting embodiment, the PSA 266 includes a
pair of beds 360, 362 and each bed 360, 362 can have adsorption
material adapted to adsorb oxygen at a higher rate than its rate of
adsorption of nitrogen. Thus, oxygen is quickly trapped by the beds
360, 362 and nitrogen can pass, preferably easily, through each of
the beds. The pressure upstream of the PSA 266 can be increased or
decreased to increase or decrease, respectively, the flow rate at
which gases pass through the beds 360, 362. Additionally, the
proportion of the inert gas to the non-inert gas produced by the
PSA 266 can be increased or decreased by decreasing or increasing,
respectively, the upstream pressure.
[0170] During a first production cycle, the valves 359, 361, 363
are closed and the fluid from the conduit 262 flows through the
conduits 364, 366 and into the bed 360. The adsorption material in
the bed 360 captures the non-inert substances in the fluid flow and
allows fluid comprising a high proportion of inert substances
(e.g., nitrogen gas) to non-inert substances to pass therethrough.
The inert substance, preferably inert fluid (e.g., an inert rich
gas), then passes out of the bed 360 and into the conduits 368,
324. The conduit 324 can then deliver the inert rich gas to the
conduit 290 (FIG. 7).
[0171] While fluid flows through the bed 360, the bed 362 can
optionally undergo depressurization and can be purged by, for
example, nitrogen rich fluid to remove non-inert substances, such
as oxygen, that has accumulated in the bed 362. The separating
capacity of the bed 362 is thus increased due to the removal of
substances from the bed. For example, the valves 369, 371 can be
closed so that fluid provided by the bed 360 pass through the
conduits 368, 373, 374 and into the bed 362 to purge the bed 362.
Optionally, valve 369 can be left open during this stage. The purge
fluid can pass out of the bed 362 and into the conduits 375, 376.
The purge fluid preferably comprises substantial amounts of
non-inert gas such as oxygen and other trace gases. Although not
illustrated, the separation system 266 can have a purge container
that contains a fluid that can be used to purge the beds 360,
362.
[0172] During a second cycle, the valves 363, 377 are opened and
the valves 383, 385 are closed. Fluid from the conduit 262 passes
through the conduit 379 and into the conduit 375 and through the
bed 362. The bed 362 can capture non-inert components of the fluid
and permit inert components to flow into the conduits 374, 324.
While the fluid flows through the bed 362, the bed 360 can
optionally undergo depressurization and can be purged by some, for
example, nitrogen rich fluid to remove oxygen that has accumulated
in the bed 360. For example, the valves 371, 369 can be closed and
the valve 370 can be opened so that fluid from the bed 362 passes
through the conduits 374, 373, 368 to purge the bed 3600f course,
the purge cycle can be performed periodically during a production
cycle.
[0173] In the illustrated embodiment, the first cycle can be
performed until the bed 360 has reached a predetermined saturation
level. For example, the first cycle can be performed until the bed
360 is generally completely saturated. After the bed 360 is
saturated, the bed 360 can be purged so that the non-inert
substances captured by the bed 360 are discharged. After the first
cycle, the second cycle can be performed until the bed 362 likewise
reaches a predetermined saturation level. The bed 362 and be
subsequently purged to remove non-inert substances from the bed
362. These acts can be repeated to produce highly purified inert
rich gas.
[0174] In some embodiments, such as that illustrated in FIG. 7D, a
vacuum pump 381 can be used to increase the performance of the PSA
266. In this arrangement, the system can be referred to as a
"Vacuum Swing Adsorption" (VSA) device. In such a device, the
vacuum pump 381 is disposed on the outlet ends of the beds 360,
362, so as to enhance the desorption process.
[0175] Embodiments incorporating a PSA or a PSA device can further
include a buffer tank, such as the buffer tank 365. In such
embodiments, the buffer tank can be configured to store pressurized
gas discharged from the bed 360, and thus provide a more continuous
flow of gas from the separation unit 266. In such embodiments, the
buffer tank 365 can be connected to the bed 360 with a discharge
line 356A, which guides gas from the bed 360 to the buffer tank
365.
[0176] A further advantage can be achieved where the buffer tank is
also connected to a valve 365C and a reverse flow line 365B. In
such embodiments, the bed 360 can also be connected to a vent line
at its inlet end. As such, when the vent is opened, the gas in the
buffer tank 36 can be used to purge the bed 360 to perform the
desorption process for the bed 360. In some embodiments, the buffer
tank 365 can be sized to be sufficiently large that the buffer tank
365 can continue to supply gas to downstream components through the
line 290 while, at the same time, purge the bed 360. As such, the
separation unit 266 can continue to operate while purging (i.e.,
the desorption process) even though it only has one tank.
[0177] With reference to FIG. 7F, in some embodiments, the
separation unit 266 can include a plurality of separation devices
comprising at least one of an adsorption device and a membrane
separation device. For example, in some embodiment, the separation
unit 266 can include, at its upstream end, an adsorption device
266A. The adsorption device 266A can be any type of adsorption
device, including but without limitation, any of the adsorption
devices disclosed herein such as the PSA shown in FIG. 7C, the VSA
shown in FIG. 7D, or the buffer tank type system shown in FIG.
7E.
[0178] The outlet of the adsorption device 266A can be connected to
the inlet of yet another separation device. In the illustrated
embodiment, the outlet of the adsorption device 266A is connected
to the inlet of a membrane device 266B. The membrane device 266B
can be any type of membrane separation device, including but
without limitation, any of the membrane separation devices
disclosed herein such as those described with reference to FIGS. 7A
and 7B, or any other known membrane separation device.
[0179] In this configuration, the gas discharged from the
adsorption device 266A is further purified by the membrane device
266B. In some embodiment, the order of the devices can be reversed.
For example, the devices 266A, 266B can be connected such that gas
discharged from the membrane device 266B is further purified by the
adsorption device 266A.
[0180] In some embodiments, the separation unit 266 can comprise a
series of membrane separation units 271A, 271B, as illustrated in
FIG. 7G. In this arrangement, the feed gas first enters the first
membrane device 271A. The permeate from this first unit 271A is
more likely to be highly contaminated. Thus, the permeate from the
membrane unit 271A can be vented out of the system. The retentate,
on the other hand, is discharged to the inlet of the second
membrane device 271B.
[0181] The permeate from the second membrane device 271B will be
less contaminated than the permeate from the first membrane unit
271A. Thus, in some embodiments, the permeate from the second
membrane unit 271B can be returned to the system at a point
upstream from the second membrane unit, such as the inlet of the
first membrane device 271A, or another location. For example, but
without limitation, the permeate from the second membrane unit 271B
can be returned to the system at the inlet to the compressor 246,
and thus eventually returns to the inlet of the first membrane
device 271A.
[0182] In some embodiments, the separation unit 266 can include
more than two membrane separation devices. Further, in such
embodiments, the permeates from each of the membrane devices
downstream from the first membrane device 271A can be returned to
the system at a point upstream of the first separation unit 271A,
such as to the inlet of the compressor 246, although these
permeates can be returned to the system at other points. In some
embodiments, the membrane separation units can be configured to
operate at different pressures, can include membranes with
different pore sizes for separating different compounds, and/or can
have other differences.
[0183] These types of arrangements can provide further advantages.
For example, exhaust gas from an internal combustion engine can
include many different compounds. Thus, using multiple separation
devices can better remove numerous compounds that exist in internal
combustion engine exhaust gas that may not be desired. Further,
different separation devices, such as PSA, VSA, and membrane-type
devices can have different performance characteristics in terms of
rate at which they can separate certain compounds out of a feed
stream of gas. Thus, by combining different types of separation
devices, the separation unit 266 can achieve better performance,
particularly in the environment of use where it is desired to
separate certain compounds out of exhaust gas of an internal
combustion engine or other environments of use.
[0184] Optionally, the conditioning system 214 (FIG. 7) can also
include a purity control system 320 for controlling the purity of
the fluid passing out of the conditioning system output 216. The
purity control system 320 can selectively determine the purity of
the fluid passing to the conditioning system output 216. In one
embodiment, the purity control system 320 can comprise one or more
valves for restricting the flow of fluid from the separation unit
266 and may have one or more sensors for measuring the contents of
the fluid flow produced by the separation unit 266.
[0185] In an exemplary but non-limiting embodiment, the purity
control system 320 includes a valve 322 for restricting the flow of
fluid from the separation unit 266, preferably a membrane
separation unit. When the inert gas concentration from the
separation unit 266 is below a predetermined amount, the valve 322
can selectively restrict the flow through the conduit 324 so as to
raise the pressure in the membrane separation unit 266. In the
illustrated embodiment of FIGS. 7 and 7A, when the valve 322
inhibits the flow through the conduit 324 which extends from the
conduit 290 to a compressor 330, the pressure within the inert
chamber 276 is increased. By raising the pressure in the inert
chamber 276, the volumetric flow rate of gas passing through the
membrane 270 and into the non-inert chamber 278 is increased. Thus,
because a greater amount of permeate gas passes through the
membrane, there is increased concentration of the inert gas
discharged from the membrane separation unit 266. Of course, the
increased upstream pressure may reduce the volumetric flow rate of
the fluid passing out the output 216.
[0186] When the separation unit 266 produces an inert gas
concentration above a predetermined amount, the valve 322 can be
opened so as to increase the flow rate of fluid through the conduit
324. By opening the valve 322, the upstream pressure can be reduced
in the conditioning system 214 while providing an increased output
from the output 216. For example, by reducing the pressure in the
separation unit 266 having a membrane, the volumetric flow rate of
gas passing from the inert chamber 276 through the membrane 270
(FIG. 7A) and into the non-inert chamber 278 may be reduced. Thus,
a reduced amount of permeate gas may pass through the membrane. In
this manner, the proportion of the inert gas to non-inert gas of
the fluid discharged from the separation unit 266 into the conduit
290 may be reduced. Thus, the valve 322 can be operated to
determine the volumetric flow rate and/or the purity of the fluid
outputted from the conditioning system 214. One of ordinary skill
in the art can determine the desired purity of the gas flowing from
the conditioning system 214 and the desired volumetric flow rate
based on the use of the gas.
[0187] With reference to FIG. 7, the purity control system 320 can
also include an inert gas sensor 334 that is configured to detect
flow parameters (e.g., the concentration of inert gases of the
fluid, the amount of fluid emanating from the separation unit 266,
and the like). The measurements from the inert gas sensor 334 can
be used to adjust the amount of fluid that flows through the
conduit 324 by operating the valve 322. It is contemplated that the
purity control system 320 can be an open or closed loop system.
[0188] Optionally, the conditioning system 214 can also include a
compressor 330 (e.g., a booster pump) that can be used to raise the
pressure of the gas discharged from the separation unit 266 to a
desired pressure. In some embodiments, the booster compressor 330
can be configured to raise the pressure of gas to about 1000 psig.
In one embodiment, the booster compressor 330 can increase the
pressure of the inert rich gas from about 200 psig to about 4000
psig. For example, the booster compressor 330 can increase the
pressure of the exhaust fluid up to about 2000 psig. Optionally,
the booster compressor 330 can be configured to increase the
pressure of the exhaust fluid up to about 5000 psig. However, the
booster compressor 330 can increase the pressure to any suitable
pressure depending on the use of the inert rich gas. Inert gas from
the booster compressor 330 can be passed through a conduit 344 and
out of the conditioning system output 216 to the upper portion 348
of a drill stem arrangement 18, as illustrated in FIG. 1. The gas
can continue to flow until it reaches the drill stem assembly 20 as
described above. Thus, the compressor 330 can be selectively
configured to raise the pressure of the gas to various pressure
levels depending on the desired flow characteristic of the gas
passing through the drill stem arrangement 18.
[0189] The engine 220 can be selected and configured to provide
sufficient flow of exhaust fluid for generating the desired amount
of inert gas outputted from the conditioning system 214 for any of
the uses of inert gas described herein. That is, the engine 220 can
be selected to output different levels of purity and different gas
flow rates. Additionally, the operating speed of the engine 220 can
be controlled to ensure further that the desired amount of exhaust
fluid is delivered to the conditioning system 214. The conditioning
system 214 is preferably configured to produce and deliver
generally highly pure inert gas which is then, in turn, used by,
for example but without limitation, a drilling operation. It is
contemplated that various components can be removed from or added
to the conditioning system 214 to achieved the desired flow
characteristics of the output fluid flow. For example, the
compressor 246 and the booster compressor 330 can be configured so
that the conditioning system output 216 discharges inert fluid at a
sufficient pressure and volumetric flow rate for any of the uses
disclosed herein. Additionally, the filtration system 252 and the
particulate filter 260 can be configured to remove any undesirable
substance in the exhaust fluid produced by the engine 220.
Optionally, one or more components of the conditioning system 214
can be removed or not used during a production cycle. For example,
during an operation cycle, the filtration system 252 and the
particulate filter 260 can be off-line if some substances do not
need to be filtered out of the exhaust fluid. In another operation
cycle, the filtration system 252 and the particulate filter 260 can
be online such that the inert gas generating system 210 provides an
extremely pure inert gas from the conditioning system output
216.
[0190] In an exemplary but non-limiting embodiment, the
conditioning system 214 may have a bypass system 350 for
controlling the mixture of the fluid flow flowing out of the
conditioning system output 216. For example, the bypass system 350
can include a bypass system conduit 352 which extends from a
location upstream from the unit 266 to a location of the
conditioning system 214 downstream from the unit 266. In the
illustrated embodiment, the bypass system conduit 352 extends from
the particulate conduit 262 to the conduit 344. However, the bypass
system conduit 352 can extend from any point along the conditioning
system 214 upstream from the separation unit 266 to any point of
the conditioning system 244 downstream from the separation unit
266.
[0191] In the illustrated embodiment, the flow passing through the
conduit 262 can be separated into a first flow flowing into the
separation unit 266 and a second flow flowing into the bypass
system conduit 352. An amount of the first flow can pass through
the separation unit 266 and through the conduits 290, 324,
compressor 330, and the conduit 344. Of course, the separation unit
266 can filter out non-inert portions of the first flow. The
concentrated inert gas flow produced by the separation unit 266 can
be combined with the second gas flow passing through the conduit
352 at the junction of the conduits 352, 344. Thus, when the
concentration of inert gas produced by the conditioning system 214
is below a predetermined amount, the bypass system 350 can reduce,
or stop, the flow of fluid through the conduit 352. By reducing the
flow of the fluid through the conduit 352, the purity of gas
discharged from the conditioning system output 216 can be
increased.
[0192] Alternatively, when the concentration of inert gas produced
by the conditioning system 214 is above a predetermined amount, the
bypass system 350 can increase the amount of fluid flowing through
the conduit 352, which is then combined with the inert fluid flow
produced by the separation unit 266. In this manner, the
concentration of inert gas outputted from the conditioning system
output 216 can be reduced. The bypass system 350 can therefore be
operated to control selectively and determine the purity of the
inert gas produced and delivered out of the conditioning system
214. Optionally, of course, the operating speed of the engine 220
can be varied to control the purity and the amount of gas
discharged from the conditioning system.
[0193] Optionally, the bypass system 350 can include a valve 354
that can be used to control selectively the flow rate of the fluid
passing through the conduit 352. Those skilled in the art recognize
that the valves of the conditioning system 214 may be manually or
automatically controlled and may comprise sensors.
[0194] Optionally, a further advantage can be achieved wherein one
or more of the components of the conditioning system 214 can be
powered by the engine 220. This provides the advantage that the
source of the exhaust fluid can also be used to provide power to
various components of the conditioning system 214. Preferably,
engine 220 can provide sufficient power to operate one or more of
the components of the conditioning system 214. Thus, those
components may not require any additional power from another power
source.
[0195] In some embodiments, engine 220 can produce exhaust fluid
and a another secondary output, such electrical power. For example,
the engine 220 can be a generation system (e.g., a generator) that
generates power in the form of electricity. The electricity can be
passed through an electrical line 348 and can be delivered to a
motor of the compressor 246. The electricity generated from the
engine 220 can therefore be used to power the compressor 246. The
engine 220 advantageously provides exhaust fluid that can be
treated by the conditioning system 214 to produce a highly pure
inert gas and can be used to power the compressor 246. It is
contemplated that one of ordinary skill in the art can determine
the appropriate sized engine 220 to provide the desired power
suitable for driving one or more of the components, such as
compressor 246.
[0196] Although not illustrated, the engine 220 can be in
communication with other components of the conditioning system 214.
For example, the engine 220 can be in communication with the
booster 330. An electric power line can provide electrical
communication between the engine 220 and the booster 330.
Additionally, the engine 220 can provide power to the compressor
246 and the booster 330 simultaneously, or independently.
[0197] Optionally, the engine 220 can be in communication with one
or more of the temperature control systems of the conditioning
system 214. For example, the engine 220 can provide power in the
form of electricity to a temperature control system that can
increase the temperature of the fluid passing through the
conditioning system 214. Optionally, the valves 322 and 354 may be
automatic valves that are also powered by the engine 220. The
valves 322, 354 can comprise controllers and other sensor devices
that can optionally be powered by the engine 220.
[0198] The engine 220 can be in communication with one or more of
the feedback devices of the conditioning system 214. Although not
illustrated, the engine 220 can have a communication line
connected, for example but without limitation, to the feedback
device 240 and also the inert gas sensor 334. The feedback devices
may selectively control the operating speed of the engine 220. For
example, if the exhaust fluid flow reaches a predetermined
volumetric flow rate, a feedback device may reduce the engine's
operating speed. Additionally, the operating speed of the engine
220 may be selectively controlled to determine the amount of power
produced by the engine 220. In one embodiment, the operating speed
of the engine 220 can be increased or decreased to increase or
decrease, respectively, the amount of electricity produced by the
engine 220.
[0199] Optionally, a further advantage can be achieved where the
engine 220 can provide mechanical power to one or more components
of the conditioning system 214. In an exemplary but non-limiting
embodiment, the engine 220 has a mechanical output system 351 in
the form of an output shaft 352 that can be connected to one or
more of the components of the conditioning system 214. For example,
the output shaft 352 in the illustrated embodiment is connected to
the mixing plenum 228. As the engine 220 operates, the output shaft
352 rotates. The rotation of the output shaft 352 can be used to
agitate the fluid contained in the mixing plenum 228. In one
embodiment, the rotational movement of the output shaft 352 is
translated into linear movement of at least one plenum within the
mixing plenum 228. The movement of the plenum can agitate fluid
comprising the exhaust fluid and the air drawn through the air
intake 230. Although not illustrated, a further advantage is
achieved where the output shaft 352 is connected to the compressor
246 to as to drive the compressor 246. In the system 210, the
compressor 246 can require substantial power to compress the gases
flowing therethrough. Thus, by driving the compressor with a shaft
from the engine 220, the compressor 246 can be driven more
efficiently. For example, a direct shaft drive connection between
the engine 220 and the compressor 246 avoids the losses generated
by converting shaft power from the engine 220 into electricity,
then back to shaft power with an electric motor at the compressor
246. Further, the entire system 210 can be made lighter and more
easily portable. For example, a mechanical connection between the
engine 220 and the compressor 246 can eliminate the need for an
electric motor for driving the compressor 246.
[0200] Optionally, a further advantage can be achieved where at
least one or more devices of the drilling operation uses inert gas
and/or power produced by the engine 220. For example, various
components of the drill stem arrangement 18 (FIG. 1) can use inert
rich gas produced by the conditioning system 214 and can be
operated by power generated by the engine 220. Many devices, such
as lights, fans, blowers, venting systems, and/or other electrical
devices, can receive power generated by the engine 220. For
example, in one non-limiting embodiment, the engine 220 generates
power that operates the compressor 246, the booster 330, lights
proximate to the generation system 210, a fan which blows across
the inert gas generating system 210, and/or a plurality of lights
that illuminate the area surrounding the drilling operation.
[0201] The engine 220 can also provide power to a battery or
storage device. For example, the engine 220 can operate and can
deliver power in the form of electricity to a battery which, in
turn, stores the power. The battery can then deliver power to one
or more components of the conditioning system 214 or the drilling
operation.
[0202] In operation generally, the engine 220 can be operated to
generate exhaust fluid. The exhaust fluid can pass through the
exhaust conduit 226 and into the mixing plenum 228. The exhaust
fluid can be discharged from the mixing plenum 228 and through the
plenum conduit 244 and into the compressor 246. The compressor 246
can increase the pressure of the exhaust gas and deliver the
exhaust gas through the conduit 250 to the filtration unit 251. The
filtration unit 251 can remove various substances from the exhaust
fluid, which is then passed through the separation unit 266. The
separation unit 266 can receive fluid having a first concentration
of inert gas and output a fluid having a second concentration of
inert gas higher than the first concentration. The inert gas can
then be passed through the conduits 290, 324 and into the booster
compressor 330. The booster compressor 330 can increase the
pressure of the fluid and discharge the fluid to the conduit 344
which, in turn, delivers the fluid out of the output 216.
[0203] With reference to FIG. 7H, a further modification of the
separation unit is illustrated therein and is identified generally
by the reference numeral 266' In this arrangement, the separation
unit 266 can include a plurality of separation devices, for
example, separation devices 266, 266a, and 266b. However, any
number of separation devices can also be used.
[0204] Each of the separation devices 266, 266a, 266b, etc., can be
constructed in accordance with the description set forth above of
the various embodiments of the separation unit 266. Thus, while the
separation device 266 may be any one of a membrane, pressure screen
adsorption, or a hybrid separation device. The separation devices
266a, 266b can be the same as the unit 266, or have a different
arrangement than the unit 266.
[0205] In some embodiments, the separation unit 266' can be
configured to allow for the selective activation or deactivation of
the plurality of separation units 266, 266a, 266b that form the
separation unit 266'. For example, the inlet side of the separation
unit 266 can include an intake manifold 267 connecting each of the
separation units 266, 266a, 266b with the conduit 262.
Additionally, the separation unit 266' can include a discharge
manifold 269 connecting the outlets of the separation devices 266,
266a, 266b.
[0206] The separation unit 266' can include a plurality of inlet
and outlet valves configured to allow each of the separation units
266, 266a, 266b to be connected to the intake and discharge
manifolds 267, 269. For example, intake valves 265, 265a, 265b can
be configured to connect the inlets of the separation devices 266,
266a, 266b, respectively, to the intake manifold 267. Similarly,
valves 273, 273a, 273b can be configured to selectively connect the
separation devices 266, 266a, 266b, respectively, to the discharge
manifold 269.
[0207] Thus, by selectively opening or closing the valves 265,
265a, 265b, 273, 273a, 273b, the devices 266, 266a, 266b can be
selectively activated or deactivated. In other words, the devices
266, 266a, 266b can either be connected or disconnected from the
intake manifold 267 and discharge manifold 269, independently.
[0208] Optionally, the system 210 can include a CO.sub.2 scrubber
340 configured to remove carbon dioxide discharged from the booster
compressor 330 through the conduit 344. Additional valves 382 can
be arranged to guide all or some of the gas discharged through the
conduit 344 into the carbon dioxide scrubber 380. The carbon
dioxide removal device 380 can be any type of such device.
[0209] Optionally, the system 210 can also include a bypass inlet
line 386 having an input port 388 configured to allow a gas to be
input into the system 210 at a point downstream from the compressor
246. However, the inlet conduit 386 can be connected to any portion
of the system 210.
[0210] In the illustrated embodiment, the inlet conduit 386 allows
a gas, such as compressed air, to be input into the system 210
bypassing the flow source 212. For example, the inlet conduit 386
can be connected to the conduit 351 so as to be downstream from the
engine 220. Optionally, the input conduit 386 can be connected to
the conduit 244 upstream from the compressor 246, and thus ambient
air can be allowed to flow into the input conduit 386 and
thereafter be compressed by the feed air compressor 246. However,
in yet other embodiments, the input conduit 386 can be connected
downstream of the conditioning system 214, as illustrated in FIG.
7.
[0211] In such arrangements, the input conduit 386 allows a gas to
be introduced into the system 210. This can be advantageous if a
portion or all of the flow source 212 or a portion or all of the
conditioning system 214 are inoperative.
[0212] For example, an alternative source 390 can be connected to
the input port 388 and thus supply fluid to the system 210
bypassing the flow source 212 and/or the conditioning system 214.
In some embodiments, the source 390 can be an air compressor
configured to discharge compressed air into the input conduit 386.
As such, the remainder of the system 210, i.e., the portion of the
system 210 downstream from the flow source 212 and the conditioning
system 214, can operate on compressed atmospheric air, or any other
source fluid. This provides an advantage that if the engine 220 is
inoperative, and/or if the compressor 246 is inoperative,
pressurized fluid can be introduced into the system 210 and be
treated by the downstream components.
[0213] In yet other embodiments, the source 390 can be in the form
of a flue gas supply. For example, in applications where the system
210 is used in the vicinity of a supply of a sufficient flow rate
of exhaust gas, or another type of gas with a reduced concentration
of oxygen, such gas can be introduced into the system 210 through
the inlet conduit 386. In some embodiments, the source 390 can be
the exhaust system of the engine driving a ship, or other kind of
vehicle.
[0214] In embodiments where the source 390 is the exhaust system of
a ship engine, such flue gas is generally at a low pressure, near
atmospheric pressure. However, this will depend on the point in the
exhaust system at which the flue gas is bled from the exhaust
system. Thus, as noted above, the source 390 can be connected to
the system 210 up or downstream from the compressor 246, depending
on the desired pressure. In other embodiments, an additional
compressor (not shown) can be used to deliver pressurized flue gas
from the exhaust system into the inlet conduit 386.
[0215] Optionally, the system 210 can also include a reheat bypass
arrangement 392. In some embodiments, the reheat bypass 392 can be
configured to direct gases from the downstream end of the system
210, for example, gases comprised of mainly nitrogen gas, to an
additional heating device.
[0216] For example, the reheat bypass 392 can include an inlet end
arrangement 393 configured to draw gas from an inlet conduit 394
connected to a point in the discharge line 324 upstream from the
booster compressor 330, an inlet line 395 connected to a part of
the system 210 downstream from the booster compressor 330, or an
inlet line 396 connected to an output of the carbon dioxide removal
device 380.
[0217] The downstream end of the bypass 392 can be connected to a
heat transfer device 397 configured to transfer heat from the
exhaust gas of the engine 220 to the gas flowing through the bypass
392. For example, the heat exchange device 397 can include a heat
input portion 398 and a heat output portion 399. In the illustrated
embodiment, the heat input portion 398 is a portion of the heat
exchanger device 397 through which the exhaust gas from the engine
220 is directed. The heat from the exhaust gas is thereby
transferred to the gas directed through the reheat bypass 392, as
it flows through the heat output portion 399. As such, gases
discharged from the downstream end of the system 210 can be
reheated through the heat transfer device 397, such that the gas
eventually discharged from the system 210 is at a desired
temperature and/or humidity for the desired application.
[0218] FIG. 8 illustrates a modified generation system and is
identified generally by the reference numeral 210'. The components
of the system 210' have been identified with the same reference
numerals as those used to identify corresponding components of the
system 210, except that "'" has been used. Thus, the descriptions
of those components are not repeated herein.
[0219] In the illustrated embodiment, the conduit 226' extends from
the engine 220' to a filtration unit, such as a catalytic converter
400. The catalytic converter 400 can remove many of the components
of the exhaust fluid passing through the conduit 226'. In an
exemplary but non-limiting embodiment, the catalytic converter 400
can be configured to remove non-inert components of the exhaust
fluid, such as carbon monoxide, hydrocarbons, volatile organic
compounds, and/or nitrogen oxides (nitrogen oxide or nitrogen
dioxide) to increase the purity of the inert gas of the exhaust
fluid.
[0220] In an exemplary but non-limiting embodiment, the catalytic
converter 400 of the conditioning system 214' comprises a reduction
catalyst and oxidation catalyst that operate to take non-inert
components out of the exhaust fluid. It is contemplated that the
catalytic converter can be an oxidation or three way type catalytic
converter depending on the desired removal of the non-inert
components of the exhaust fluid. The construction and operation of
such catalytic converter is well known in the art and thus further
description of the construction and operation is not repeated
herein.
[0221] A catalytic converter conduit 406 extends between the
catalytic converter 400 and a fluid separation unit 408.
Preferably, the fluid separation unit 408 includes a high
temperature membrane configured to remove the water from the
exhaust fluid passing therethrough.
[0222] For example, the engine 220' can output exhaust fluid
comprising various gases and a liquid, such as water. The fluid
separation unit 408 can remove the water from the exhaust fluid as
the fluid passes through the unit 408. In one embodiment, the fluid
separation unit 408 has a membrane (not shown) that is configured
to allow gases to pass therethrough without permitting the passage
of water. In other words, the gas component of the exhaust fluid
can flow into and out of the fluid separation unit 408 and into the
conduit 412. The membrane of the fluid separation unit 408 can
remove water from the exhaust fluid and deliver it to a water knock
out vessel in the unit 408. The water knock out vessel can be
periodically removed from the unit 408 and emptied. Additionally, a
coalescing filter (not shown) can be provided to remove oil
carryover that may be present in the exhaust fluid.
[0223] Optionally, the fluid separation unit 408 can have a heat
exchanger to increase the temperature of the fluid delivered by the
conduit 406. The heat exchanger can increase the temperature of the
liquid component of the exhaust fluid for easy removal of the
liquid.
[0224] The conditioning system 214' can also include a temperature
control system 416 that is connected to the fluid separation
conduit 412. The temperature control system 416 can be configured
to increase or reduce the temperature of the exhaust fluid fed from
the fluid separation conduit 412. Because the fluid separation unit
408 may have features, such as a heat exchanger, to raise the
temperature of the exhaust fluid, the temperature control system
416 can be configured to reduce the temperature of the exhaust
fluid to desirable temperatures for feeding the exhaust through the
temperature control system conduit 420 and into the compressor
246'.
[0225] The conditioning system 214' can have a compressor 246'
which raises the pressure of the exhaust fluid. The compressor 246'
then delivers the fluid to a compressor conduit 250', which, in
turn, feeds the exhaust fluid to a filtration unit 424. That
filtration unit 424 can be configured to capture and remove
undesired substances that may be present in the exhaust fluid. The
filtration unit 424 can be can similar or different than the
filtration unit 251.
[0226] The exhaust fluid from the filtration system 424 can pass
through the conduit 262' and into the separation unit 266'. The
separation unit 266' can be similar or different that the units
illustrated in FIGS. 7A, 7B, 7C, 7D, 7E, 7F, 7G, and 7H. The
separation unit 266' can receive exhaust fluid and can remove at
least a portion of the non-inert component of the exhaust fluid and
pass inert rich gas into the conduit 324'. The inert fluid can then
be fed into the booster pump 330'. The booster pump 330' can
increase or decrease the pressure of the fluid and can pass the
fluid into the conduit 344' and out of the conduit system output
216'.
[0227] The engine 220', of course, can generate and provide power
to one or more components of the conditioning system 214'. For
example, the engine 220' can be in electrical communication with at
least one of the compressors 246', 330'. The engine 220' can
therefore power one or more of the compressors which can provide a
pressure increase in the conditioning system 214. Optionally, the
engine 220' can provide power to any other type of power
consumption device.
[0228] Optionally, a further advantage can be achieved where the
inert gas generation systems 210, 210' can be arranged in one or
plurality of containers. For example, but without limitation, the
systems 210, 210' can be assembled into a single ISO container or
broken down into simple parts and assembled into a plurality of ISO
or other containers. An ISO container containing parts or complete
inert gas generation system 210, or 210', can be conveniently
transported to various locations.
[0229] The generation systems 210, 210' can be used in a variety of
applications. Additionally, due to the benefits provided by various
features of the generation systems 210, 210', further advantages
are achieved with respect to some applications.
[0230] With reference to FIGS. 9A and 9B, any of the embodiments
disclosed above with reference to either of the generation systems
210, 210', as noted above, can be configured to be mobile units,
such as the mobile separation system 200 illustrated in FIG.
6A.
[0231] FIGS. 9A-37 illustrate exemplary but non-limiting
embodiments of mobile separation units 200A (FIGS. 9A and 9B) and
200B (FIG. 32). In each of these embodiments 200A, 200B, any of the
above-described embodiments of the separation systems 210, 210' can
be used. Thus, although the mobile separation units 200A, 200B are
described below in the contents of specific arrangements of the
separation systems included therewith, any of the above-identified
separation systems 210, 210' can be used.
[0232] Additionally, FIGS. 9A-36 include dimensions, sizes,
material thicknesses, model numbers, voltages, etc. However, these
values are merely disclosed for purposes of providing exemplary
embodiments of at least some of the inventions disclosed herein.
These values do not limit the inventions disclosed herein.
[0233] With reference to FIGS. 9A-30, components of the mobile
separation unit 200A that are the same or similar components as the
mobile separation unit 200 have been identified with the same
reference numerals, except that that a "A" has been added thereto.
Additionally, because the separation system 210A of the mobile
separation unit 200A can be any of the above-described embodiments
of the separation systems 210, 210', many of the components,
features, and functions of the separation system 210A are not
repeated below.
[0234] Additionally, it is to be noted that FIGS. 9A-37 include
reference numerals set off by parenthesis. The reference numerals
contained within the parenthesis in these figures do not correspond
to the reference numerals used in the text of this specification.
Rather, the text of this specification uses reference numerals that
are not set off in parenthesis in the figures.
[0235] The mobile separation unit 200A can include a control cab
205 and a suspension device 208A. The control cab 205 can include a
plurality of control panels and devices for controlling the various
parts of the separation system 210A. Additionally, the control cab
205 can include all of its own dedicated control panels in a NEMA 4
enclosure. Compressor controls can indicate critical oil
temperatures and pressures, as well as exhaust gas pressures and
temperatures. The membrane control system can also provide
instantaneous and cumulative nitrogen flow information, as well as
nitrogen purity pressure, pure pressures, and temperatures.
[0236] FIGS. 33-37 include various schematic diagrams of control
panels in units that can be disposed within the control cab 205 for
remotely controlling the various corresponding devices within the
separation system 210A.
[0237] For example, as is illustrated in many of the following
schematic diagrams, the components of the separation system 210A
can be controlled with electronics, including electronically
controlled pneumatic actuators. Thus, with reference to these
schematic diagrams, one of ordinary skill in the art can determine
how to connect the various components of the separation systems
210A with control devices disposed within the control cab 206A.
[0238] The suspension device 208A can be in the form of a trailer,
such as those commonly designed to be pulled by a towing vehicle
referred to as a "tractor," for on-highway transportation. The
design, suspension, wheels, etc. of the suspension unit 208A can be
determined based on the total weight of the unit 200A. In the
illustrated embodiment, the suspension device 208A includes three
axels at its rear end, and is configured to be towed as a "fifth
wheel trailer." However, other configurations can also be used.
[0239] As noted above, the separation system 210A can be in the
form of any of the above-identified embodiments and modifications
of the separation system 210, 210'. Thus, the following description
of the separation system 210A is merely an exemplary but
non-limiting embodiment of the features, devices, and methods of
operation of the separation systems 210, 210'. However, other
configurations can also be used.
[0240] As shown in FIGS. 9A, 9B, the mobile separation unit 200A
includes a flow source 212A, a conditioning system 214A, and an
output 216A. In the illustrated embodiment, the flow source 212A is
in the form of a feed air compressor 246A configured to draw in
atmospheric air, compress the air, and deliver it to the
conditioning system 214A. The conditioning system 214A can include
a filtration unit 251A and a separation unit 266A.
[0241] The gases leaving the conditioning system 214A are guided to
the output 216A. In some embodiments, the output 216A is a booster
compressor configured to raise the pressure of the gases discharged
from the conditioning system 214A.
[0242] With reference to FIG. 10, the feed air compressor 246A can
include an engine 220A, a compressor 246A, and an outlet conduit
250A. During operation, the engine 220A can drive the compressor
246A, and thereby pressurize atmospheric air and discharge it
through the output 250A.
[0243] However, the feed air compressor 246A can include many other
devices and features that are optional. Many of these optional
features are illustrated in FIG. 10. Set forth below is a
description of some of the optional features. The features that are
illustrated in FIG. 10 but not described below can be readily
implemented by those of ordinary skill in the art.
[0244] With continued reference to FIG. 10, the feed air compressor
246A can include an intake filter unit 500, an oil separator 502, a
pressure loading device 504, an after cooler 506, and a water
separator 508, as well as other features.
[0245] For example, but without limitation, the feed air compressor
246A can also include engine coolant input and output ports 510,
512 for allowing engine coolant to be circulated through a heater,
described in greater detail below. Further, the feed air compressor
246A can include compressor oil input and output ports 514, 516 for
allowing the lubricating oil for the compressor 246A to be
circulated through a heater, described in greater detail below.
[0246] During operation, the separation process can be commenced by
starting the flow source 212A. For example, the engine 220A can be
started. After a delay, for example, to allow the engine 220A to
warm up, the feed air compressor 246A can be started. For example,
a clutch mechanism 518 can be selectively engaged to allow the
engine 220A to selectively drive the feed air compressor 246A.
[0247] After the feed air compressor 246A begins to turn, ambient
air begins to enter the system through the inlet and filter device
500. As such, pressure begins to build in the oil separator
502.
[0248] While the engine 220A is idling or operating at a low engine
speed, the system 210A can be unloaded. For example, the pressure
loading device 504 can be "open" so as to allow pressurized air
from the feed air compressor 246A to be vented. However, other
techniques can also be used to allow the system to remain unloaded
while the engine 220A is idling or operating at low engine
speed.
[0249] In some embodiments, the flow source 212A is substantially
unloaded so that the maximum pressure reached in the flow source
212A is only about 40-60 psig. However, the separation flow source
212A can be designed to reach other maximum pressures when the
engine 220A is idling or running at low speeds, depending on the
application. When the engine 220A is idling or operating at low
speed, very little or substantially no air is flowing through the
flow source 212A or the conditioning system 214A.
[0250] As the flow source 212A is loaded, the engine 220A can be
adjusted to run at a target operating speed (e.g., 1800 to 2100
rpm), and the pressure loading device 504 can be controlled to load
the compressor 246A to increase the pressure up to a target
pressure. As noted above, the pressure loading device 504 is
configured to operate from a remote location. For example, the
pressure loading device 504 can include electrically controlled
pneumatic actuators for operating the various valves and devices
within the pressure loading device 504.
[0251] When the flow source 212A is loaded, the engine 220A can
operate at normal operating speeds. In some embodiments, the
pressure can be increased to about 350 psig (2.4 MPa). At this
point, the compressor 246A can deliver air to the after cooler
device 506 where the air can be cooled.
[0252] For example, but without limitation, the after cooler device
506 can be configured to bring the temperature of the compressed
air down to within about 15.degree. F. of the ambient temperature.
After the after cooler device 506, the compressed air can be guided
to the water separator device 508 and then out of the output 250A
to the conditioning system 214A.
[0253] In some embodiments, the engine 220A can be a high
performance diesel engine. For example, but without limitation, the
engine 220A can be a Caterpillar C-16 ATAAC high performance engine
rated at about 630 bhp at 1800 rpm or equivalent. The engine can be
cooled by a radiator that incorporates an air charge cooler and a
fuel cooler. The fan for the heat exchanger can be driven off of
the front of the engine via a pulley arrangement. The engine 220A
can also be equipped with electronic engine controls to ensure low
emissions and improved fuel economy. Any number of various types of
engines can also be employed.
[0254] In some embodiments, the feed air compressor 246A can be a
Sullair two-stage oil flooded rotary screw compressor or another
type of a compressor, configured to couple, directly or indirectly,
for example, through the clutch mechanism 518, to the engine 220A.
The air filter 500 can be a heavy duty air filter configured to
remove larger particles from the incoming air. The compressor 246A
can be fitted with an unloading valve 519 on its inlet end.
[0255] The unloading valve 519 can be part of the pressure loading
device 504, and can be configured to modulate the inlet flow into
the compressor 246A to control the capacity of the compressor, and
as may be desired or required by system operating conditions. The
air from the compressor 246A can flow directly to the oil separator
502 where oil can be removed from the air stream down to about 2-3
parts per million. The air and oil can then each be directed to
their own section of an air cooled heat exchanger assembly (not
shown) which can be combined with the radiator of the engine 220A.
However, other configurations can also be used. By cooling the
compressed air, water vapor in the compressed air is condensed and
becomes liquid which can be removed by the water separator 508.
[0256] With continued reference to FIG. 10, although the after
cooler 506 is illustrated as a single device, the after cooler 506
can be in the form of a plurality of heat exchangers. For example,
the after cooler 506 can be in the form of a main heat exchanger
and a second heat exchanger. The main heat exchanger can contain
one or more of the following: the radiator of the engine 220A, an
engine air charge cooler, an engine diesel fuel cooler, a
compressor oil cooler, and a compressed air after cooler.
[0257] In some embodiments, the main heat exchanger can be located
on the front of the engine 220A, although the main heat exchanger
can be positioned at other suitable locations. The second heat
exchanger can be a compressed air reheater and can use hot
compressor oil to heat the cooled and dried feed air up to a
desired operating temperature, for example, for more ideal
operation of the membrane separation process. The reheater can be
located next to the compressor oil separator or on the membrane
tower.
[0258] The water separator device 508 can be any known type of
water separator device. In some embodiments, the water separator
device 508 is a centrifugal-type water separator device disposed on
the discharge side of the after cooler device 506. Such a
centrifugal water separator device can remove the bulk of liquid
water from the compressed air. As noted above, the pressurized air
is discharged from the flow source 212A from the outlet 250A.
[0259] With reference to FIG. 11, the filtration unit 251A can
receive the compressed air from the flow source 212A at its inlet
520. The filtration unit 251A can include a plurality of filtering
devices. In the illustrated embodiment, the filtration unit 251A
includes four coalescing filters 522, 524, 526, 528.
[0260] The coalescing filters 522, 524, 526 can each include an
auto drain system 530 configured to drain liquids out of the
filters 522, 524, 526 into a common drain discharge 532. Although
not illustrated, the coalescing filter 528 can also include an auto
drain system.
[0261] Additionally, in the illustrated embodiment, the filtration
unit 251A includes a carbon tower unit 534. However, other
configurations can also be used.
[0262] Filtered air is discharged from the filtration unit 251A
through its discharge 534. Optionally, the filtration unit 251A can
include a feed air heater system 540. The feed air heater system
540 can include any type of heating device configured to heat the
air traveling through the filtration unit 251A.
[0263] In the illustrated embodiment, the feed air heater device
540 includes a heat transfer device 542 (FIGS. 11 and 20) disposed
between the initial three coalescing filters 522, 524, 526 and the
carbon tower 534. However, other configurations can also be used.
In the illustrated embodiment, the heat transfer device 542 is
supported on a membrane tower 620, described in greater detail
below.
[0264] The feed air heater assembly 540 can also include a
plurality of valves 544 configured to allow air from the upstream
side of the heating device 540 to be passed through the heat
transfer device 542 or to bypass the heat transfer device 542. By
operating the valves 544 in an appropriate manner, the temperature
of the air discharged from the heater 540 can be controlled even
where the heat transfer device 542 is operated continuously or
non-continuously or with uniform or changing internal
temperatures.
[0265] The coalescing filters 522, 524, 526 can have the same or
different designs. For example, the filter 522 can be configured to
remove condensate. For example, but without limitation, the filter
device 522 can be a device configured to form a water separator and
a moisture separator filter configured to remove at least about 99%
of condensate along with larger particulates. The removed
condensate can be collected in the collector within the filter unit
522. For example, the filter unit 522 can include a condensate
drain bowl or other suitable device. When the drain bowl is full,
the drain bowl automatically opens, with the operation of the auto
drain devices 530, and thus dumps the condensate into the drain
532.
[0266] The partially dry air can then enter coalescing filters 524,
526. These filters 524, 526 can be configured to remove about
99.999% of all fine aerosols as well as particles 0.01 microns and
larger, however, other filters can also be used. These coalescing
filters 524, 526, as noted above, can also include auto drain
devices 530 for dumping condensates to the drain 532.
[0267] As noted above, the feed air heater device 540 can be used
to control the temperature of the air flowing through the
filtration unit 251A. For example, the dried compressed air from
the filters 522, 524, 526 can be reheated before entering further
filtering devices. For example, the air can be reheated before
entering the carbon tower 534.
[0268] In some embodiments, the heat added to the compressed air
flowing through the heating device 540 can be transferred to the
heat transfer device 542 from the compressor oil of the compressor
246A (FIG. 10). As shown in FIG. 11, the feed air heating device
540 can include fluid input and output ports 550, 552. The ports
550, 552 can be connected so as to direct hot compressor oil from
the output port 516 (FIG. 10) to enter the input port 550 (FIG.
11).
[0269] As such, the hot compressor oil can travel through the heat
transfer device 542 and thereby impart heat into the compressed air
flowing through the feed air heater 540. After passing through the
heat transfer device 542, the compressor oil can return to the
compressor 246 by being discharged through the output port 552 and
reintroduced through the input port 514 (FIG. 10). This design
provides additional efficiency in that the heat contained within
the circulating compressor oil from the compressor 246A would
normally be discharged as waste heat. Thus, this waste heat can be
utilized for improving the performance of the filtration unit 251A
without the need for additional energy input. However, other
designs can also be used.
[0270] The valves 544, as noted above, can be used to adjust the
temperature of the compressed air ultimately discharged from the
feed air heater device 540. For example, the air flowing through
the feed air heater device 540 can be modulated to either flow
through the heat transfer device 542 or to by-pass the heat
transfer device 542. The valves 544, as noted above, can be
electronically actuated pneumatic valves. Thus, a control device
(not shown) can be configured to utilize the output from
temperature sensors 554, 556 to control the valves 544 and to
thereby adjust the temperature of the compressed air ultimately
discharged from the feed air heater device 540.
[0271] More specifically, the heating process performed by the feed
air heater device 540 can be controlled by the valves 544 that are
controlled to open and close based on the measurement of the
temperatures by the temperature sensors 554, 556. The control,
which can be in the form of a program run by a general purpose or
purpose-made processor, uses the output from the temperature
sensors 554, 556 to control the valves 544. In some non-limiting
embodiments, the temperature of the compressed air discharged from
the feed air heat device 540 can be set at approximately
120-130.degree. F. (49.degree. C.-54.degree. C.). The reheating of
the air as such keeps the air temperature substantially above the
dew point temperature of the air. As such, little or no condensate
forms as the air travels through the carbon absorber of the carbon
tower 534, and thus proceeds to the membrane separator. Any
suitable type of heat exchangers can be used to control the
temperature of the air. Exemplary heaters include, but are not
limited to, resistance heater, double pipe heat exchangers, and the
like.
[0272] As noted above, the reheated air enters the carbon tower
534. The carbon tower 534 can be configured to remove substances to
increase the operating life of downstream equipment. In some
embodiments, the carbon tower can be configured to remove
hydrocarbon vapors from the compressed air. In some embodiments,
the compressed air or gases exit the carbon tower 534 with less
than 5 parts per billion (ppb) of hydrocarbon vapors (excluding
methane). This low concentration of hydrocarbon vapor can maximize
nitrogen membrane operating life. Other types of filters can also
be used to remove undesirable substances from the compressed air or
other gases.
[0273] With reference to FIGS. 12-14, the filters 522, 524, 526,
528 can be mounted in one integral filter unit 560. This provides a
unique and compact arrangement. In some embodiments, because the
filters 522, 524, 526, 528 can all be generally the same type of
coalescing filter, although designed to filter out different size
particles or droplets, they can have the same general overall shape
and configuration, as shown in FIGS. 12-14.
[0274] The filter stand 560 includes a base portion 562 configured
to support the assembly 560 on an upper surface of the suspension
device 208A (FIGS. 9A, 9B). The assembly 560 can also include at
least one upright member 564 to which the filters 522, 524, 526,
528 are mounted. In some embodiments, as shown in FIGS. 12-14, the
assembly 560 includes a plurality of cross members 566, 568 for
supporting the filters 522, 524, 526, 528 at both lower and upper
positions. However, other configurations can also be used.
[0275] This space saving arrangement can be accomplished even
though, in the direction of air flow through the perspective
filters, the carbon tower 534 is disposed between the filter 526
and 528. Although this requires additional plumbing connecting the
discharge end of the filter 526 to the feed air heater 540 and the
carbon tower 534 and additional plumbing to connect the output side
of the carbon tower 534 to the input side of the filter 528, the
structural similarities of the filter devices 522, 524, 526, 528
allow for a compact design that is more space efficient.
[0276] FIGS. 15-18 illustrate an exemplary embodiment of the carbon
tower 534. As shown in FIGS. 15-18, the carbon tower 534 is
included within a carbon tower assembly 570. The carbon tower
assembly 570 can include a base 572 and a plurality of upright
support members 574 configured to support the carbon tower 534 in a
generally upright configuration.
[0277] In this configuration, the carbon tower 534 includes an
inlet 576 at its upper end and an outlet 578 at its lower end. The
inlet 576 is connected to the feed air heater device 540 and the
outlet 578 is connected to the inlet side of the filter 528 (FIG.
12).
[0278] With reference to FIG. 9A, the arrangement of the filter
unit 560 and the carbon tower unit 570 provides a compact
arrangement enhancing the overall space efficiency of the system
210A, and thus allowing the overall size of the suspension unit
208A to be made as small as possible.
[0279] With reference to FIG. 19, the separation unit 266A can be
configured and constructed in accordance with any of the
above-described separation devices 266, 266'. Thus, like reference
numerals are used to identify components of the separation unit
266A that correspond to the above-described separation units 266,
266'
[0280] The separation unit 266A can include an inlet 262A and an
outlet 290A. In the illustrated embodiment, the separation unit
266A includes an array of membrane separation devices 266a, 266b,
etc. arranged in parallel with each other, such as the arrangement
partially illustrated in FIG. 7H.
[0281] During operation, the filter gases discharged from the
output 534 (FIG. 11) of the filtration unit 251A are guided to the
inlet 262A of the separation device 266A. The illustrated
separation unit 266A includes a pair of bundles, each comprising a
plurality of membrane units (266a, 266b), which in the illustrated
embodiment, are membrane separation units. Each of the membrane
separation units 266a, 266b can be configured to separate one or
more components of the gas input into the input port 262A.
[0282] The membrane separation units 266a, 266b can allow certain
substances to permeate therethrough. In some embodiments, the
separation units comprise membranes in the form of a bundle of
hollow fibers configured to separate the air flow, as described
above. For example, the separation membranes can allow oxygen,
water vapor, and carbon dioxide to permeate the walls of the hollow
fibers, leaving a high pressure concentration of nitrogen on the
inside of the hollow fibers.
[0283] During normal operation, in some exemplary but non-limiting
embodiments, the pressure in the membrane separation units 266a,
266b can be maintained at about 330-350 psig (2.3-2.4 MPa) through
the use of a flow control valve device 322A. The nitrogen can be
collected in a manifold, identified generally by the reference
numeral 600, and can be directed through the flow control valve
322A.
[0284] In some embodiments, a product isolation valve 602 can be
used to vent the flow of some of the nitrogen overboard during that
portion of the production cycle. In some embodiments, the product
isolation valve 602 can be opened to vent the flow of nitrogen out
of the system during warm-up until the nitrogen purity reaches the
minimum desired level. Once the flow of nitrogen reaches the target
purity, the product isolation valve 602 can be closed. Exemplary
membrane separation units can be used to separate any desired gas
(e.g., inert gases) from a feed gas. As such, an output gas of a
particular desired purity can be produced.
[0285] With reference to FIGS. 20-23, the separation unit 266A can
be assembled into a single integral membrane tower 620. As shown in
FIGS. 20-23, the membrane tower 620 can include an arrangement of
membrane separation units 266a, 266b in two vertical stacks,
although other numbers of stacks can also be used. This provides a
high level of space efficiency due to the vertical stacking
arrangement, and thus further enhances the ability of the
separation system 210A to be disposed on a suspension unit 208A for
transportability.
[0286] In the illustrated embodiment, the membrane tower 620
includes a base 622 and at least one vertical support configured to
support the weight of the individual membrane separation units
266a, 266b. In the illustrated embodiment, the tower 620 includes
four vertical members 624, 626, 628, 630 configured to support each
of the individual membrane separation devices 266a, 266b. However,
other numbers of vertical supports and/or configurations can be
used.
[0287] With reference to FIG. 20, each of the individual membrane
separation devices 266a, 266b are suspended from the vertical
supports 624, 626, 628, 630 by cross member devices 632. However,
other configurations can also be used.
[0288] The membrane tower 620 can include a plurality of intake and
discharge manifolds 640, 642, respectively, for feeding each of the
individual membrane separation devices 266a, 266b. As shown in FIG.
22, all of the intake manifolds 640 are disposed at one end of the
tower 620 and all of the discharge manifolds 642 are disposed at
the opposite end. However, other configurations can also be
used.
[0289] In some embodiments, the intake manifold 640 is connected to
the inlet 262A, and thus receives filtered air from the filter unit
251A. The discharge manifold 642 can be connected to the outlet
290A, and thus is used for discharging nitrogen from the separation
unit 266A.
[0290] A further advantage is achieved where the structural
components of the tower 620 are used both for providing structural
support for the tower 620 as well as for fluid handling. In the
illustrated embodiment, the vertical support 628, 630 include
permeate discharge manifolds 650, 652, each of which are connected
to the individual membrane separation devices 266a, 266b so as to
allow the permeate gases to flow into the permeate manifolds 650,
652. This provides an additional space and weight efficiency in
that the vertical supports 650, 652 are used both for supporting
the weight of the components of the separation device 266a as well
as for guiding fluids.
[0291] The permeate entering the vertical supports 650, 652 can be
discharged to the atmosphere, or it can be handled in other ways.
However, in other embodiments, the manifolds 650, 652 can be used
for intake air or the discharge of nitrogen gas.
[0292] Optionally, the separation device 266A can include a flow
meter 654. Additionally, as noted above, the membrane tower 620
supports the heat transfer device 542. As illustrated in FIGS. 21
and 23, the heat transfer device 542 is supported by the vertical
members 626, 630 and is arranged generally horizontally. This
provides an additional advantage in that the heat transfer device
542 is similar in shape to the membrane devices 266a, 266b, etc.,
and thus can be supported by the tower 620 in a compact and
space-saving configuration. For example, but without limitation,
the heat transfer device 542 is nested with the other membrane
devices 266a, 266b, etc. In other words, there is a vertical stack
of membrane devices 266a, 266b, stacked above the heat transfer
device 542 with both the membrane devices 266a, 266b, and the heat
transfer device 542 supported by the same members, in this case,
the vertical members 626, 630 at a position that could other wise
have been used to support additional membrane devices 266a, 266b.
As such, the heat transfer device is compactly positioned between
the membrane tower 620 and the filter stand 560 without the need
for an additional separate mounting arrangement for supporting the
heat transfer device 542 relative to the trailer.
[0293] Both the filter unit 251A and the separation unit 266A,
including the above-described space efficient tower designs, as
noted above, provide a particularly compact design that is helpful
in arranging the components of the separation system 210A into a
configuration that will fit on an on-highway device, such as the
suspension device 208A. For example, with the arrangement of the
mobile separation system 200A described herein, all the components
can be supported on a single 53 ft. long trailer or on a
self-propelled unitary frame truck of about 41 ft. long. However,
other size trailers and trucks can also be used.
[0294] As noted above, the output 216A of the system 200A can
include a booster compressor 330A. The booster compressor 330A can
be configured to raise the pressure of the nitrogen gas discharged
from the separation device 266A to a desired pressure.
[0295] The booster compressor 330A can include an engine 700 and a
compressor device 702. Optionally, the booster compressor 330A can
include a clutch mechanism 704 for selectively engaging the engine
700 with the compressor device 702.
[0296] The booster compressor 330A can also include an inlet 706
connected to the outlet of the membrane separation unit 266A.
[0297] During operation, nitrogen gas flowing into the inlet 706
can initially be received in a nitrogen receiver device 708. The
nitrogen can then enter a first stage booster compressor 710 of the
compressor device 702. Optionally, the compressor device 702 can
include second and third stages 712, 714, the operation of which is
described in greater detail below.
[0298] In some non-limiting exemplary embodiments, the pressure of
the nitrogen can be increased up to about 600 psig (4.1 MPa) in the
first stage 710. The pressurized nitrogen can be discharged out of
the compressor device 702 and into a first stage of a high pressure
heat exchanger 716. The high pressure heat exchanger 716 can be
configured to cool the nitrogen compressed by the first stage 710.
Optionally, the first stage heat exchanger 716 can have an output
connected to an oil separator 718 configured to separate any
compressor oil in the compressed nitrogen.
[0299] After leaving the oil separator device 718, the compressed
nitrogen can be introduced into this second stage compressor 712.
After being compressed by the second stage compressor 712, the
nitrogen can be further compressed by the third stage compressor
714. After passing through each of the second and third stage
boosters 712, 714, the pressurized gas discharge from each stage
can optionally be directed into another high pressure heat
exchanger and/or additional oil separation devices.
[0300] For example, pressurized nitrogen discharged from the second
stage 712 can be directed to a second stage high pressure heat
exchanger configured to cool the pressurized gas and a second stage
oil separation device 722 configured to separate oil out of the
compressed nitrogen. Similarly, pressurized nitrogen discharged
from the third stage booster 714 can be directed through a third
stage heat exchanger 724 and, optionally, an additional oil
separator (not shown).
[0301] The flow of pressurized nitrogen can be controlled by a
combination of inlet pressure variations to the booster 702, e.g.,
by modulating the flow control valve 654 (FIG. 19) and/or by
changing the speed at which the booster compressor 702 is operated.
For example, the speed of the crankshaft or the engine 700 can be
changed by adjusting a "throttle" position of the engine 700.
Changing the speed of the engine 700 also thus changes the speed of
the compressor 702.
[0302] Optionally, the flow of nitrogen can also be controlled by
passing nitrogen from the final discharge 730 back to the first
stage 710 of the compressor 702. For example, a bypass line 732,
which is connected to the discharge side of the third stage
compressor 714, can also be connected back to an inlet side of the
first stage compressor 710. In some embodiments, as illustrated in
FIG. 24, the bypass line 732 is connected to the nitrogen receiver
tank 708. From there, this highly pressurized nitrogen can then be
again fed into the first stage compressor 710.
[0303] Optionally, a high pressure control valve 734 can be used to
control the flow of nitrogen through the bypass line 732. Nitrogen
that is not bypassed through the bypass line 732 can be directed to
the final discharge 730. Optionally, the final discharge 730 can
also include a check valve 740 and a plug valve 742 with an
integral discharge port. However, other configurations can also be
used.
[0304] In some embodiments, the booster compressor 330A can be a
hurricane model 6T-276-43B-4000 compressor, or an equivalent. Such
a nitrogen booster can deliver high pressure nitrogen to about
5,000 psig (35 MPa). The booster can be a single stage or have a
plurality of stages of compressors.
[0305] In the illustrated embodiment, the booster compressor 330A
includes three stages 710, 712, 714. However, other numbers of
stages can also be used.
[0306] The booster can be constructed with a water cooled
reciprocating compressor engine having a suction pressure of about
320-350 psig (2.2-2.4 MPa). As noted above, the intercoolers can be
provided between one or more of the stages to dissipate the heat of
compression. Additionally, an air cooled aftercooler can also be
provided to reduce the temperature to within about 20.degree. F.
(11.1.degree. C.) of ambient temperatures.
[0307] The engine 700 of the booster compressor 330A can be a
diesel engine, or any other type of engine. The engine 700 can be
coupled directly or indirectly (perpendicular) to the booster 702.
Additionally, as noted above, a clutch mechanism 704 can optionally
be used to selectively connect and disconnect the engine 700 from
the booster 702.
[0308] The engine 700 can be, in an exemplary but non-limiting
embodiment, a Caterpillar C9 diesel engine rated at 350 bhp at
1,800 rpm or an equivalent engine. Such an engine can have a
6-cylinder configuration with a total engine displacement of 732
cubic inches. If the booster is driven indirectly with a high tower
and PTO drive (perpendicular) by a diesel engine from a
self-propelled carrier or a tractor diesel engine that pulls the
trailer mounted equipment, the engine can be rated at 500 bhp or
greater.
[0309] With reference to FIG. 25, the mobile separation system 200A
can include a supplemental heater system 800. For example, where
the system 200A will be operated in arctic-like conditions, the
supplemental heater system 800 can be configured to assist in
start-up and operation of the system 200A.
[0310] In some embodiments, with continued reference to FIG. 25,
the supplemental heater system 800 can be configured to circulate
engine coolant from the engines 220, 700 through heating devices
802, 804, respectively. For example, as noted above, with reference
to FIG. 10, the engine 220A can include engine coolant input and
output ports 510, 512. Coolant from these ports can be connected to
the heater 802 via input and output ports 808, 810.
[0311] Similarly, the engine 700 can include coolant input and
output ports 750, 752 (FIG. 24) can be connected to coolant input
and output ports 812, 814 (FIG. 25). As such, engine coolant from
the engine 700 can be circulated through the heater device 804. As
such, engine coolant from the engine 220A can be circulated through
the heater 802.
[0312] The heaters 802, 804 can generate heat in any known manner.
For example, the heaters 802, 804 can include fuel supply lines for
kerosene or diesel fuel for generating heat to heat the engine
coolant. However, other types of heaters can also be used.
Additionally, the heaters 802, 804 can be used to heat other
devices within the system 200A as well. For example, in some
embodiments, the supplemental heater system 800 can also be used to
heat the batteries and fuel of each of the engines 220A, 700.
[0313] In some embodiments, the supplemental heater system 800 is
formed in essentially two independent systems, one system heating
the feed air compressor engine, batteries, control cabin heater,
and the intake fuel line. The other independent system can be used
to warm the engine of the booster compressor, the booster block
itself, batteries, fuel tank, and intake fuel lines.
[0314] For example, with continued reference to FIGS. 25 and 28-30,
the heater 802 can be powered by the batteries of the feed air
compressor device 212A, and can be configured to burn diesel fuel
from the common diesel fuel tank 820. The heater 802 can include a
pump (not shown) configured to pull engine coolant from the engine
220A and through the heater manifold device 822. The heater
manifold device can be used to circulate heated engine coolant into
heat exchanger devices 824, 826 that are in thermal communication
with the batteries of the feed air compressor 212A. Similarly, the
heat from the heater 802 can be used to provide heat to a heat
exchanger device 828 configured to transfer heat to portions of the
control cab. Similarly, heat from the heater 802 can be directed to
a heat exchanger device 830 for heating fuel for the engine 220A.
The heater 804 can include similar plumbing for heating other
devices.
[0315] As noted above, the complete mobile separation system 200A
can be operated from a central location, for example, the control
cabin 205. However, in other embodiments, such controls can be
mounted within the sleeper portion section of a self-propelled
carrier or another remote control box.
[0316] The control system can be configured to use a combination of
PLC (Programmable Logic Controller) equipment (FIGS. 35-37) and a
touch screen arrangement (FIG. 33) for allowing an operator to
operate and monitor the system 200A. The central operating location
allows for functions, such as starting engines, controlling
nitrogen purity, pressure, and flow rate. The central operation
system also provides continuous feedback of the operating status of
the separation system 200A via the touch screen display.
[0317] FIG. 26 illustrates an electrical schematic of the feed air
module. FIG. 27 illustrates an electrical schematic of the booster
compressor module 330A. These two figures, 26, 27, show the
electrical systems for operating engine driven components from one
central location.
[0318] FIG. 34 illustrates a power distribution system which can be
provided at the central location to power the PLC monitoring system
and other ancillary equipment, such as a cabin heater, fan, and
lights.
[0319] As noted above, FIG. 33 illustrates a touch screen device
840 and an Electronic Control Unit (ECU) 841. The ECU 841 can be in
the form of any type of device that can accept input from sensors
and provide output to actuators. For example, but without
limitation, the ECU 841 can be in the form of a hard-wired control
circuit. Alternatively, the ECU 841 can be constructed of a
dedicated processor and a memory for storing a computer program
configured to perform the functions of the ECU 841 described
herein. Additionally, the ECU 841 can be constructed of a general
purpose computer having a general purpose processor and the memory
for storing the computer program for performing the functions of
the ECU 841 described above.
[0320] In the illustrated but non-limiting embodiment, the ECU 841
is in the form of a programmable logic controller which has a
plurality of Programmable Logic Controller (PLC) slots 842, 844
that can be used for monitoring the separation system operation
200A. The PLC slot 804 can be used to connect the PLC system to a
recording device (e.g., lap top computer) so that the separation
system operations can be recorded for future use or comparison.
[0321] FIG. 35 illustrates connections with the PLC slot identified
as "Slot 0" which can be used to provide digital display devices
850, 852, 854. The digital data can be collected by the PLC slot
identified as "Slot 5" (FIG. 33).
[0322] FIGS. 36 and 37 illustrate optional uses for the PLC slots
identified as "Slot 1"-"Slot 4," and "Slot 6." These connections
illustrate how different operating data, such as feed air module
pressure and temperature, filter and membrane module, pressures and
temperatures, operate the automatic filter dump valves, nitrogen
purity, nitrogen flow rate, and booster modules pressures and
temperatures. However, other arrangements can also be used for
displaying operating data of the separation system 200A in case the
touch screen 840 is not operating correctly. This is a back-up
monitoring system that can display all the data that the touch
screen provides by selecting the parameter from the display
selector shown in FIG. 36.
[0323] With continued reference to FIG. 32, a modification of the
mobile separation system 200A is illustrated therein and identified
generally by the reference numeral 200B. The components of the
mobile separation system 200B can be the same as those identified
above with reference to the separation system 200A, except as
expressly indicated below. Thus, components of the system 200B
corresponding to the system 200A that are similar or the same are
identified with the same reference numeral, except that a "A" has
been changed to a "B."
[0324] As with the system 200A, the mobile separation system 200B
can include a feed air compressor or a flow source 212B, a
conditioning system 214B, and an output device 216B.
[0325] In this embodiment, the output device 216B, which is in the
form of a booster compressor 330B, is essentially the same as the
booster compressor 330A, except that the booster compressor 330B
does not include an engine that can provide the sole means for
powering the booster compressor unit 702B. Rather, the system 200B
includes a PTO device configured to convert shaft power from an
engine 900 disposed with the propulsion device 206B to drive the
compressor unit 702B.
[0326] The engine 900 can be any type of engine. In this
embodiment, the engine 900 is configured to generate shaft power
for driving one or a plurality of the front wheels 902 and/or the
rear wheels 904 of the system 200B. The PTO device 906 can be any
type of known PTO device.
[0327] In the illustrated embodiment, the PTO device 906 is
configured to receive shaft power from, for example, a first drive
shaft 910 driven by the engine 900, and use that shaft power to
drive a second vertical drive shaft (not shown) which is connected
to the compressor unit 702B. Additionally, a third drive shaft 912
can extend rearwardly from the PTO device 906 to the axle of one or
more of the rear wheels 904.
[0328] The propulsion device 206B can include an internal control
for changing the mode of operation of the PTO device 906. For
example, the input device (not shown) can allow an operator of the
propulsion device 206B to change the operation of the PTO device
906 between two modes of operation, including, for example, but
without limitation, a mode in which shaft power from the shaft 910
is directed only to the compressor unit 702, and a second mode in
which shaft power from the shaft 910 is only directed to the drive
shaft 912 for powering one or more of the rear wheels 904. Such a
type of input control and PTO device are well known in the art, and
thus are not described in further detail.
[0329] Such an arrangement provides a substantial advantage in that
the cost of an additional engine, such as an engine 700 (FIG. 24),
can be avoided. Rather, the booster compressor 330B can utilize the
shaft power from the engine 900, which, when the booster compressor
330B is not being used, can be used to move the system 200B. This
provides a significant savings in weight and in the cost of
engines. In some embodiments, the PTO device can be configured to
drive the feed air compressor 246B.
[0330] Further advantages can be achieved where exhaust from the
engine 900 is fed to the inlet of the feed air compressor 212B. For
example, as shown in FIG. 32, the engine 900 can include an exhaust
discharge 920 configured to guide exhaust gases from the combustion
chambers within the engine 900 toward the atmosphere. Of course, as
is widely known in the art, the engine 900 can also include
pollution controls which reduce or eliminate certain contaminants
that can be found in exhaust gases from internal combustion
engines, such as diesel engines.
[0331] As explained above with reference to the separation systems
210, 210', exhaust gas, such as the exhaust gas discharge from the
exhaust discharge 920, can be fed to the inlet 500B of the feed air
compressor 212B. As such, the system 200B can operate to separate
nitrogen out of the exhaust gas discharge from the engine 900. This
provides further advantages, as noted above, in that there is
significantly less oxygen in the exhaust gas from an internal
combustion engine than there is in ambient air. Thus, for some
applications, the entire system 200B can be run at lower power
settings because there is overall less oxygen to separate out of
the gases being fed to the conditioning system 214B.
[0332] Additionally, with such a configuration, all of the
equipment that can be disposed in the control cab 205 can be
contained in the cab of the propulsion unit 206B.
[0333] As such, because the cabs of trucks are normally provided
with sufficient light, heaters, and weather protection, it is not
necessary to provide a separate control cab such as the control cab
205 (FIGS. 9A, 9B). Thus, with all the control panels disposed
within the cab of the propulsion unit 206B, further savings are
achieved.
[0334] Optionally, the propulsion unit 206B can be provided with a
"sleeper cab," which can therefore provide more room for control
panels and for the operator to operate such control panels, as well
as room for a passenger in the propulsion unit 206B.
[0335] With reference to FIG. 38, the ECU 841, along with the
various sensors, actuators, displays, and control devices noted
above, can form an electronic control system 860. It is to be noted
that the electronic control system 860 can be used with any of the
above-described embodiments of the mobile separation units 200,
200A, 200B. Thus, although only components of the mobile separation
system 200A are referenced below with respect to certain features,
functions or advantages, those of ordinary skill in the art will
understand how the description of the electronic control system 860
can be used with the other mobile separation systems 200, 200B.
[0336] As reflected in the schematic of FIG. 38, at least some of
the sensors and actuators of the mobile separation system 200A can
be grouped or organized based on the components of the separation
system 200A with which they operate. For example, as described
above, the separation system 200A can include a feed air compressor
246A, a separation unit 266A, and an output, which can be in the
form of a booster compressor 216A. As noted above, each of these
devices 246A, 266A, 216A, include various sensors and actuators
that are used during operation of these respective devices.
[0337] For example, the feed air compressor 246A can include, as
illustrated in FIG. 10, a compressor discharge pressure sensor 900
and a compressor outlet temperature sensor 902. Additionally, other
sensors can also be considered as effecting or effected by the
operation of the compressor 246A, and thus, can be considered part
of the compressor sensors. For example, but without limitation, the
nitrogen flow rate, nitrogen purity, and booster inlet pressure,
are all affected by the operation of the compressor 246A. Thus, the
compressor sensor group 900 can be considered to also include the
nitrogen flow meter 654 (FIG. 19) which, optionally, can also
include a nitrogen purity sensor 906.
[0338] Further, the compressor sensors group 900 can also include a
pressure sensor 908 (FIG. 19) which is disposed at an outlet of the
membrane separation unit 266A. However, because it is at the outlet
end of the membrane separation unit 266A, it can also be considered
as providing the pressure at the inlet of the booster 216A.
[0339] The compressor 246A can also have a group of actuators 910
associated with the operation of the feed air compressor 246. For
example, but without limitation, the feed air compressor 246 can
include a combustion air valve 912 (FIG. 10) for controlling the
flow of air into the engine 220A, an engine speed control actuator
914 (FIG. 26), a starter switch 916, the unloading valve 519 (FIG.
10), and/or other actuators.
[0340] Similarly, the membrane separation unit 266A can include a
membrane sensors group 920 and a membrane actuator group 922. The
membrane sensors group 920 can include, similarly to the compressor
sensor group 900, sensors that are specifically dedicated to only
the membrane separation unit 266A as well as sensors that are also
considered part of other sensor groups.
[0341] For example, the membrane sensors group 920 can include the
compressor outlet temperature sensor 902, the nitrogen purity
sensor 906, the nitrogen flow sensor 654, the temperature sensor
556 indicating the temperature at the outlet of the heater 542, the
temperature sensor 554 indicating the temperature at the inlet of
the heater 542, a temperature sensor 922 (FIG. 11) configured to
detect the temperature of the gases discharged from the filter
assembly 251A, or, in other words, flowing into the membrane system
266A, and one or plurality of additional temperature sensors 924,
926, disposed on the outlet end of the membrane separation unit
266A. The membrane actuator group 922 can include the flow control
valve 322A (FIG. 19), a dump valve 928 configured to vent all of
the nitrogen gas from the membrane separation unit 266A, as well as
other actuators.
[0342] Additionally, the booster compressor 216A can include a
booster sensors group 930 and a booster actuator group 932. The
booster sensors group 930 can include the temperature sensor 926 at
the outlet of the membrane separation unit 266A (FIG. 19), the
pressure sensor 908, a pressure sensor 934 at the discharge end of
the booster compressor 216A, a temperature sensor 936 configured to
detect the temperature at the outlet of the booster compressor, a
pressure sensor 938 configured to detect a pressure produced by the
first stage of the booster compressor, a pressure temperature
sensor 940 configured to detect a temperature at the outlet of the
first stage of the booster, a pressure sensor 942 configured to
detect a pressure at the outlet of the second stage of the booster
compressor, a temperature sensor 944 configured to detect a
temperature at the outlet of the second stage of the booster
compressor, a temperature sensor 946 configured to detect the
temperature at the discharge of the third stage of the booster
compressor, a pressure sensor 948 configured to detect an oil
pressure in the booster compressor, as well as other sensors.
[0343] The booster actuator group 932 can include a plurality of
actuators configured to allow an operator to operate the booster
compressor 216A. For example, the booster actuators group 932 can
include actuators (not shown) for starting, loading and controlling
a pressure output from the booster compressor 216A.
[0344] The electronic control system 860 can also include other
sensors and actuators, schematically represented by the other
sensors group 960 and other actuators group 962. Those of ordinary
skill in the art can readily determine what sensors and actuators
may be used to provide further operability of the mobile gas
separation system 200, 200A, 200B.
[0345] Additionally, the electronic control system 860 can also
include an external sensors group 964 and an external actuators
group 966. The external sensors group 964 can include any other
sensor that an operator or user may desire to use at a site of
operation of the mobile separation system 200, 200A, 200B. Thus,
the electronic control system 860, as part of the external sensors
group 964, can include one or a plurality of auxiliary sensors
input ports configured to allow a sensor (not shown) external to
the mobile separation units 200, 200A, 200B, to be connected to the
ECU 841. As such, a user or operator can monitor the output of such
an external sensor from the same location from which the output of
the other sensors are monitored, or other locations.
[0346] Similarly, as part of the external actuators group 966, the
electronic control system 860 can include connectors or output
ports configured to allow other external actuators to be connected
to the ECU 841. As such, a user or operator of the electronic
control system 860 can operate other actuators from the same
location that the above noted actuators are operated, or from
another location.
[0347] As one exemplary but non-limiting embodiment, a sensor that
can be considered part of the external sensors group 964, in a well
drilling operation, is a pressure sensor (not shown) that can be
mounted at a gas discharge outlet so as to monitor the pressure at
which a gas, originally supplied by the system 200A, is discharged
from a well during the drilling operation. As such, the discharge
pressure of the booster 216A can easily be compared with the
discharge pressure detected by such an external sensor. Those of
ordinary skill in the art can determine other types of external
sensors and/or actuators that can also be used.
[0348] As shown in FIG. 38, the electronic control system 860 also
includes a control panel 970, an exemplary but non-limiting
embodiment of which is illustrated in FIG. 39. With continued
reference to FIG. 38, the control panel 970 can include a plurality
of indicators 972, and a plurality of input devices 974 configured
to allow an operator or user to input commands into the ECU 841.
Additionally, the control panel 970 can optionally include an
input/output (IO) display 840, such as, for example, but without
limitation, a "touch screen" device.
[0349] With reference to FIG. 39, the control panel 970, including
the indicators 972, input devices 974, and the I/O display 840, can
be disposed in an control cabin 205 (FIG. 9B), the cab of a
propulsion device 206B (FIG. 32) or any other location.
[0350] As illustrated in FIG. 39, the control panel 970 can be
considered as including four different panels; a feed air
compressor panel 980, a nitrogen flow control panel 982, a booster
compressor panel 984, and a display panel 986.
[0351] The feed air compressor panel 980 can include any number of
various indicators and input devices for the convenience of an
operator. In the illustrated but non-limiting embodiment, the feed
air compressor panel 980 includes a plurality of warning lamps 988,
including a check engine lamp 990, a warning lamp 992, and a
compressor high temperature lamp 994. These warning lamps 990, 992,
994 are configured to provide overt warnings to the operator of the
control panel 970.
[0352] For example, the check engine lamp 990 is illuminated by the
ECU 841 when the controller of the engine 220A issues a check
engine warning. The warning lamp 992 can be configured to be
illuminated when voltage of the battery of the engine 220A is too
low. Additionally, the compressor high temperature lamp 994 can be
configured to be illuminated when the temperature detected by the
temperature sensor detected by the temperature sensor 904 (FIG. 10)
is over a temperature threshold.
[0353] The feed air compressor panel 980 can also include an engine
monitor system 996 which can include a plurality of additional
warning lamps and a generic display device that can be adjusted to
display a number of operating parameters of the engine 220A. Such
monitoring devices are well known and commercially available. In an
exemplary but non-limiting embodiment, the engine 220A is a diesel
engine made by the Caterpillar Corporation. The monitoring system
996 illustrated in FIG. 39 is available from the Caterpillar
Corporation. Additionally, the panel 980 can include a voltage
meter 998 configured to continuously display a voltage of a battery
of the engine 220A.
[0354] The panel 980 can also include a warm up control knob 1000,
a high-low pressure valve control knob 1002 and an engine control
switch 1004. The warm-up control knob 1000 (FIG. 39) can be
configured to control a pressure loading device 504 (FIG. 10) which
can provide for cold weather starting. When placed in the "Start"
position, the warm-up control valve cuts off the pressure signal to
the pressure regulating valve causing the inlet valve 519 (FIG. 10)
to remain closed. This will allow the engine 220A (FIG. 10) to run
unloaded until it is properly warmed up at which time the warm-up
control knob 1000 (FIG. 39) can be set in the "Run" position which
can open the inlet valve 519 (FIG. 10) and cause the feed air
compressor 246A (FIG. 10) to start producing air flow.
[0355] The control knob 1002 can be configured to allow the feed
air compressor 246A to operate under a high or low pressure mode,
the low pressure mode being used during start-up. For example, The
High-Low pressure control knob 1002 (FIG. 39) can be configured to
allow the feed air compressor 246A (FIG. 10) to operate under rated
pressure or forces the compressor to a lower standby pressure.
[0356] Finally, The engine control knob 1002 (FIG. 39) can be
configured to de-energize the control power and shut the engine
220A (FIG. 10) off by moving to the OFF position. In the Start
position, control power is energized and the engine start will
start the engine 220A (FIG. 10). After the engine 220A (FIG. 10) is
started, the control knob can be released and the knob will return
to the Run condition.
[0357] The control panel 970 can include a plurality of heat
control switches 1006. For example, the heater control switches
1006 can include a main heater toggle switch 1008, a filter heater
toggle switch 1010 and a cab heater switch 1012. However, these are
merely optional switches and controls that can be used, other
controls can also be used.
[0358] The nitrogen flow panel 982 can include a nitrogen gas flow
control knob 1014, a totalizer reset knob 1016, a filter dump
control 1018, a main power knob 1020 and an emergency stop button
1022. The nitrogen flow control knob 1014 can be connected, through
the ECU 841, to the nitrogen flow control valve 322A. In some
embodiments, the control 1014 is used only during low pressure
operation. The totalizer reset 1016 can be configured to signal the
ECU 841 to reset a counter that can be configured to cumulatively
calculate the total amount of nitrogen gas delivered by the
corresponding system 200, 200A, 200B.
[0359] The filter dump control 1018 can be configured to operate
the valve 928. For example, if desired, the valve 928 can be opened
to depressurize and thus discharge the nitrogen gas out of the
nitrogen separation unit 266A.
[0360] The power actuator 1020 can be configured to control power
to the control panel 970. Finally, the emergency stop actuator 1022
can be configured to shut off the engines of both the feed air
compressor 246A and the booster compressor 216A. The nitrogen
control panel 982 could also include other controls.
[0361] The booster compressor panel 984 can include controls
similar to that of the feed air compressor panel 980. For example,
the booster compressor panel 984 can include an engine monitoring
device 1030 configured to display various operating parameters of
the engine 700 (FIG. 24) of the booster compressor. In a
non-limiting exemplary embodiment, the monitoring device 1030 is a
Murphy Powerview 100, which is commercially available. However,
other engine monitoring devices can also be used.
[0362] In the illustrated embodiment, the booster compressor panel
984 includes a plurality of analog gauges configured to
continuously display certain operating parameters of the engine
700. For example, the booster compressor panel 984 includes a
tachometer 1032, an exhaust temperature gauge 1034, a coolant gauge
1036 configured to display a temperature of the coolant of the
engine 700, and an oil pressure gauge 1038 configured to display an
oil pressure of the engine 700. Additionally, the booster
compressor control panel 984 can include a plurality of circuit
breakers 1040.
[0363] The booster compressor panel can also include a three-way
off/run/by-pass switch 1042, a starter button 1044, an indicator
light 1046, a loading switch 1048 and an engine rpm adjustment knob
1050. The three-way Off/Run/By-Pass switch 1042 can be configured
to de-energize the control power and shut the engine 700 (FIG. 24)
off by moving to the OFF position. When placed in the "By-Pass"
position, the bypass valve 746 (FIG. 24) is energized to allow the
engine 700 (FIG. 24) to start without loading the booster 702 (FIG.
24). After the engine 700 (FIG. 24) is started, the switch can be
released and the switch will return to the Run condition.
[0364] The starter button 1044, can be connected through the ECU
841 to the starter 916 of the feed air compressor engine 700 (FIG.
26). The loading switch 1048 can be connected to a valve for
loading or unloading the booster compressor 216A. The engine rpm
control 1050 can be connected to a throttle sensor 914 which can be
used by the engine 700 to adjust the engine speed of the engine
700.
[0365] The booster compressor panel 984 can also include a filter
heater toggle switch 1052, a pumper fault relay 1054, a main heater
toggle switch 1056, and an air temperature fault relay 1058,
however, other controls can also be included.
[0366] The display panel 986 can include any number of display
devices configured to display the status of various components of
the systems 200, 200A, 200B, the output of the various sensors
described above, or any other parameter.
[0367] The display devices 850, 852, 854, described above with
reference to FIG. 35, are generic digital four-digit display panels
configured to display numeric or alphanumeric representations of
the output or status of various components of the systems 200,
200A, 200B. Optionally, the control panel 970 can include control
knobs 1060, 1062, 1064, configured to define which parameters
displayed on each of the devices 850, 852, 854, respectively.
Preferably, the knobs 1060, 1062, 1064, are configured to allow the
display devices 850, 852, 854 to display any one of the parameters
described below with reference to the input/output device 840.
[0368] The input/output device 840 can be in the form of any known
generic or graphical display, commonly used in the computer
industry. In the illustrated but non-limiting embodiment, the
display 840 is a "touch screen" device. The following figures
illustrate exemplary but non-limiting user screens that can be
programmed into the ECU 841 for the display and control of various
parameters. These figures, which include FIGS. 40 through 53,
include an exemplary set or sub-set of screens that can be provided
with one of the systems 200, 200A, 200B. However, other screens can
also be included.
[0369] Optionally, upon actuation of the main power switch 1020
(FIG. 39), the display 840 can include a log in screen (not shown),
which requires a user to enter a user name or a password.
[0370] The ECU 841 can be configured to display any screen as the
initial screen after log in is completed. In some embodiments, the
first screen viewable after log in is complete, is shown in FIG.
40. In each of the user interface screens, illustrated in FIGS.
40-53, the screen includes a header area 1080 indicative of the
values or fields displayed on the screen. For example, the screen
illustrated in FIG. 40 is the "nitrogen generation unit" screen.
This screen is intended to be a summary overview of a subset of the
data received by the ECU 841. The data fields illustrated in FIG.
40 as included in the nitrogen generation unit screen are merely
exemplary, other data fields can also be used. In some embodiments,
the ECU 841 is configured to allow a user to change the fields
displayed on each screen.
[0371] As shown in FIG. 40, the nitrogen generating unit screen
includes a booster discharge pressure field 1082 that is configured
to display data indicative of the pressure from the booster
compressor 216A. For example, the field 1082 can be configured to
display data indicative of the output of the sensor 934 (FIG. 24).
The nitrogen generating unit screen can also include a booster
discharge temperature field 1084 configured to display a value
indicative of the temperature of the gas discharged from the
booster compressor 216A. For example, the field 1084 can be
configured to display data indicative of the output of the
temperature sensor 936.
[0372] This screen can also include a field 1086 configured to
display a value indicative of the opening degree of the valve 742
(FIG. 24). In some embodiments, those values can be expressed as a
percentage, 100% being fully opened.
[0373] The nitrogen generating unit screen can also include a field
1088 configured to display a flow rate of nitrogen being discharged
from the associated system 200, 200A, 200B. For example, the field
1088 can be configured to display data indicative of the output
from the sensor 654 (FIG. 19).
[0374] This screen can also include a field 1090 configured to
display total amount of gas discharged from the associated system,
200, 200A, 200B. Thus, the ECU 841 can be configured to provide a
running total of the amount of gas discharged from the associated
system. Additionally, as noted above, the control panel 970 can
include a totalizer reset 1016 (FIG. 39). As such, the reset 1016
can be configured to clear the running total displayed in the field
1090.
[0375] With continued reference to FIG. 40, the nitrogen generating
unit screen can also include a field 1092 configured to display the
purity of nitrogen discharged from the associated system. For
example, the field 1092 can be configured to display data
indicative of the output from the sensor 906 (FIG. 19).
[0376] The nitrogen generating unit screen can also include a field
1094 configured to display a temperature of the gases entering the
membrane separation unit 266A. For example, the field 1094 can be
configured to display data indicative of the output of the sensor
922 (FIG. 11). Finally, this screen can also include a field 1096
configured to display the pressure at the outlet of the feed air
compressor 216A. For example, the field 1096 can be configured to
display data indicative of the output of the pressure sensor 902
(FIG. 10). However, other fields can also be included.
[0377] Additionally, the nitrogen generating unit screen can also
include a plurality of fields that are "active" in the sense that a
user can touch the screen in these areas to select or trigger a
function associated with that field. These fields, as used herein,
are referred to as "buttons" for ease of description.
[0378] For example, as illustrated in FIG. 40, the nitrogen
generating unit screen can include a next button 1100, a silence
button 1102, a system configuration button 1104, a calibration
button 1106, and a log out button 1108.
[0379] The next button 1100 is configured to trigger the ECU 841 to
display the next screen; a plurality of such screens are described
with reference to FIGS. 41-53. The silence button 1102 can be
configured to silence all audible alarms associated with the
display 840.
[0380] The system configuration button 1104 can be configured to
cause the ECU 841 to display a system configuration screen on the
display 840. Similarly, the calibration button 1106 can be
configured to cause the ECU 841 to display a calibration screen on
the display 840. Finally, the log out button 1108 can be configured
to cause the ECU 841 to exit the operation mode of the system and
require a password to be input before any further use of the
display 840 is allowed.
[0381] Optionally, the nitrogen generating unit screen can include
a graphical representation of the entire system associated with the
control panel 970. In the illustrated embodiment, the system
associated with the control panel 970 is the system 200A and the
graphical representation 1110 is a graphical representation of a
side elevational view of the system 200A.
[0382] Optionally, the graphical representation 1110 can include
labels indicating the location at which the data from the various
fields 1082-1096 are detected. For example, the graphical
representation 1110 can include a position identifier 1112
schematically representing a general position on the system 200A at
which the data in the booster discharge pressure field 1082 is
detected. Optionally, indicators or labels similar to the label
1112 can be provided for each of the fields 1084-1096.
[0383] Further, the graphical representation 1110 can be configured
to only generate such indicators when a user presses a portion of
the screen in the vicinity of the fields 1082-1096. For example,
the graphical representation 1110 can normally be displayed without
any labels including the label 1112. Then, only if a user or
operator presses the field 1082, does the ECU 841 generate the
label 1112. This technique can be used for any or all of the fields
1082-1096 as well as any of the fields described below with
reference to FIGS. 41-53.
[0384] Further, the ECU 841 can be further configured to only
generate labels, such as the label 1112, if the data from the
corresponding sensor or other component breaches a threshold value
indicating an alarm or a time period for maintenance of that
particular sensor or component. Optionally, the ECU 841 can be
configured to cause such a label to blink and/or also trigger an
audible alarm. As such, a user or operator is quickly and
conveniently reminded of the location at which the corresponding
sensor or component is located.
[0385] It is to be noted that the screens described below with
reference to FIGS. 41-53 include some of the same data fields
identified above with reference to FIG. 40. Thus, a description of
those fields will not be repeated.
[0386] With reference to FIG. 41, the ECU 841 can also be
configured to display a "compressor" screen which can be organized
to illustrate data relevant to the operation of the booster
compressor 246A. For example, in addition to the fields 1088, 1092,
1096 described above with reference to FIG. 40, the compressor
screen can also include a compressor outlet temperature field 1120
configured to display a temperature of the gases discharged from
the compressor. For example, the field 1120 can be configured to
display data indicative of the output of the temperature sensor 936
(FIG. 24).
[0387] The compressor screen can also include a booster inlet
pressure field 1122 configured to display a pressure at the inlet
of the booster compressor 216A. For example, the field 1122 can be
configured to display data indicative of the output of the sensor
908 (FIG. 19). Although the sensor 908 is disposed downstream from
the membrane separation unit 266A, and thus, is not spatially close
to the compressor 246A, the booster inlet pressure is affected by
the operation of the feed air compressor 246A. For example, if the
booster inlet pressure is too low, the compressor discharge
pressure, which can be displayed in field 1096, can be raised until
the booster inlet pressure is at an acceptable level. Thus, the
compressor screen provides an advantage in that an operator has
relevant information conveniently arranged for the operation of the
system 200, 200A, 200B.
[0388] In addition to the "buttons" 1100, 1102, 1104, 1106, 1108
described above with reference to FIG. 40, the compressor screen
can also include a previous button 1124 configured to allow a user
to return to a previously viewed screen.
[0389] Additionally, the compressor screen includes a graphical
representation 1126 including a schematic representation of a
booster compressor. The graphical representation 1126 can include
all the features and options described above with reference to the
graphical representation 1110 illustrated in FIG. 40. Thus, the
description of those features will not be repeated.
[0390] With reference to FIG. 42, the ECU 841 can also be
configured to display a membrane section screen. In addition to the
fields described above with reference to FIGS. 40 and 41, the
membrane section screen can also include a heater inlet temperature
field 1130 configured to display a temperature of the gases
entering the heater device 540. For example, the field 1130 can be
configured to display data indicative of the output of the
temperature sensor 554 (FIG. 11). Additionally, the membrane
section screen can also include a heater outlet temperature field
1132 configured to display a temperature of the gases discharged
from the heater 540. For example, the field 1132 can be configured
to display data indicative of the output of the temperature sensor
556 (FIG. 11).
[0391] Further, the membrane section screen can include a membrane
inlet temperature field 1134 configured to display a temperature of
the gases entering the membrane separation unit 266A. For example,
the field 1134 can be configured to display data indicative of a
temperature detected by the temperature sensor 922.
[0392] Finally, the membrane section screen can include a graphical
representation 1136. In the illustrated embodiment, the graphical
representation 1136 includes a schematic illustration of the
membrane separation unit 266A as well as the filter assembly 251A.
As such, as noted above with reference to the graphical
representation 1110 of FIG. 40, the graphical representation 1136
can be modified to include indicators or labels corresponding to
the status or state of the sensors and/or components displayed in
the above noted fields.
[0393] With reference to FIG. 43, the ECU 841 can also be
configured to display a booster screen configured to display data
relevant to the operation of the booster compressor 216A. In
addition to the fields described above, the booster screen can also
include a booster first stage pressure field 1138 configured to
display a pressure at the discharge at the first stage of the
booster compressor 216A. For example, the field 1138 can be
configured to display data indicative of the pressure detected by
the pressure sensor 938 (FIG. 24). Additionally, the booster screen
can include a booster second stage pressure field 1140 configured
to display a pressure at the discharge of the second stage of the
booster compressor 216A. For example, the field 1140 can be
configured to display data indicative of the output of the pressure
sensor 942 (FIG. 24).
[0394] The booster screen can also include a booster inlet
temperature field 1142, a booster first stage temperature field
1144, and a booster second stage temperature field 1146. These
fields 1142, 1144, 1146 are configured to display temperatures
corresponding to the titles of those fields. For example, the field
1142 can be configured to display data indicative of the output of
the sensor 926, the field 1144 can be configured to display data
indicative of the output of the sensor 940, and the field 1146 can
be configured to display data indicative of the output of the
sensor 944.
[0395] The booster screen can also include a booster oil pressure
field 1150 configured to display a pressure of the oil of the
booster compressor 216A. For example, the field 1150 can be
configured to display data indicative of the output of the sensor
948 (FIG. 24).
[0396] With continued reference to FIG. 43, the booster screen can
also include a booster third stage temperature field 1152
configured to display a temperature of the third stage of the
booster compressor 216A. For example, the field 1152 can be
configured to display data indicative of the output of the
temperature sensor 946 (FIG. 24).
[0397] Additionally, the booster screen can also include a
graphical representation 1160 of the booster compressor 216A. As
noted above with reference to the graphical representations 1110,
1126, 1136, the graphical representation 1160 can also be modified
to include labels or indicators, the description of which will not
be repeated.
[0398] Optionally, the ECU 841 can be configured to display an "all
devices" screen configured to display the data from all sensors
described above. Additionally, although not illustrated, the "all
devices" screen can also include a graphical representation (not
shown) of the entire system 200, 200A, 200B, such as the graphical
representation 1110.
[0399] With reference to FIG. 45, the ECU 841 can also be
configured to display a system configuration screen, for example,
when a user activates the system configuration buttons 1104, to
allow an operator to adjust various operating parameters of the ECU
841 and/or corresponding system 200, 200A, 200B.
[0400] With reference to 46, the ECU 841 can also be configured to
display other screens configured for adjusting parameters of
feedback control loops. For example, as illustrated in FIG. 46, the
ECU 841 can be configured to display a membrane temperature and
touch screen temperature control screens. With respect to the
membrane temperature control field 1170, this screen includes a
plurality of buttons 1172, 1174, 1176, and 1178 configured to allow
a user or operator to set a temperature at which the ECU 841 is to
use as a target temperature for maintaining the temperature of the
gases output from the membrane separation unit 266A.
[0401] In the illustrated embodiment, the buttons 174, 176, 178
each provide the user the option of using a predetermined
temperature setting of 130.degree., 100.degree., 115.degree.,
respectively. Additionally, the button 1172 allows a user to
maintain a currently detected temperature, as displayed in the
temperature field 1180. Another field, 1182 is configured to
display the set temperature under which the system is
operating.
[0402] The screen illustrated in FIG. 46 also includes a touch
screen temperature tuning field 1184 that is configured to allow a
user to adjust the sensitivity of the touch screen 840.
[0403] The screen of FIG. 46 also includes a membrane temperature
control tuning button 1186. By depressing this button, the user
advances to the screen illustrated in FIG. 47.
[0404] As shown in FIG. 47, a tuning screen allows a user to access
a number of parameters for adjusting the operation of the feedback
control routine used by the ECU 841 for maintaining a temperature
discharged from the membrane separation unit 266A. In some
embodiments, the ECU 841 uses the output of the sensor 926 to
control the operation of the valves 544 to adjust the temperature
of the gases discharged from the filtration unit 251A, which
thereby controls the temperature of the gases discharged from the
membrane separation unit 266A.
[0405] The remaining screens illustrated in FIGS. 48-54 provide
means for a user or operator to adjust various settings with
respect to different sensors and components of the corresponding
system 200, 200A, 200B. The fields and buttons illustrated in these
figures are generally self-explanatory to those of ordinary skill
in the art. Thus, a further description of these screens is not set
forth herein.
[0406] Additionally, with respect to the screens illustrated in
FIGS. 40-44, any one of these screens can include an additional
field (not shown) for displaying the output of the sensors included
in the external sensors group 964 (FIG. 38). The ECU 841 can be
configured to allow a user to edit any one of the screens
illustrated in FIGS. 40-44 to include an additional field for
displaying the output of such a sensor.
[0407] It is contemplated that inert gas, such as nitrogen rich gas
(N.sub.2), can be used for various applications. For example, the
inert gas can be used in manufacturing facilities. In one
embodiment, inert gas can be used in semiconductor manufacturing
processes. Many kinds of inert gas (e.g., nitrogen gas) can be used
to purge and provide an inert environment for semiconductor wafer
processing. The inert environment prevents air from contacting
materials that are prone to oxidation. Nitrogen can be used to
purge equipment, such as equipment used in refineries or
petrochemical plants. For example, inert gas can be employed to
purge fluid lines containing explosive or flammable fluids. Many
kinds of fluid lines can be purged of dangerous fluids before
components in the fluid system are replaced or repaired. Inert
gases can also be used in other settings, such as for packaging to
prevent oxidation of packed items. Set forth below are additional
examples of application for which the systems 200, 200A, 200B can
be used.
Coal Mine Fire Suppression
[0408] For example, the systems 200, 200A, 200B, or other
generation systems, can be used to suppress or stop underground
coal mine fires. As is known in the art, underground coal mine
fires can burn for years if fed by a source of air leaking into the
coal mine from the atmosphere. Reducing or removing the available
oxygen for combustion can extinguish these fires.
[0409] However, extinguishing coal fires is difficult given the
large surface areas that would have to be treated with inert gas to
stop the leak of oxygen into the mine. Such a large source of inert
gas must have a sufficiently low content of oxygen to not only
extinguish the fire, but to keep the fire out while the combustible
materials cool down so that they do not reignite when oxygen
eventually is reintroduced. The latest technologies include special
foaming agents utilizing nitrogen or other inert gases as a carrier
gas for the foam. The foam treats the surface of the coal ash on
the unburnt coal fuel so as to provide a barrier that prevents
oxygen from reaching the unburned coal. The foam also helps seal
off crevices and leakage points to isolate the fire from incoming
oxygen and contain the fire in desired locations within the mine.
As such, fires are extinguished more quickly than with using
nitrogen gas alone because the foam can better isolate and stop the
spreading of fires within the mine.
[0410] The systems 200, 200A, 200B, or other systems, can be used
to suppress coal mine fires, with or without a carbon dioxide
separation process.
[0411] Thus, because the carbon dioxide removal device 380 can
generate a significant back pressure, the flow rate and discharge
pressure of gases from the system 210 can be higher if the gases
are not passed through the carbon dioxide removal device 380.
[0412] In the application of coal mine fire suppression or
extinguishing, the discharge pressures from the system 210 can be
in the range of about 100-125 psig, as this is a common pressure
range to use for foam generation or direct injection of nitrogen
gas into a coal mine fire. Thus, in some applications, it is not
necessary to run the booster compressor 330.
[0413] Additionally, often times, mines are equipped with high
capacity air compressors. Thus, with reference to FIG. 7, the
source 390 can be in the form of an air compressor at the site of a
coal mine. Such compressed air can be delivered directly to the
intake conduit 386 and thus passed through the separation device
266 to generate the desired nitrogen gas. Further, this technique
can also be used if the engine 220 and/or the compressor 246 are
inoperable.
[0414] In some embodiments, the purity of the inert gas, such as
nitrogen gas, can be adjusted by adjusting the capacity of the
separation device 266, 266'. For example, as illustrated with
reference to FIG. 7H, the separation unit 266' can be adjusted so
as to activate or deactivate the desired number of separation
devices 266, 266a, 266b. For example, as noted above, the valves
265, 265a, 265b, 273, 273a, 273b, can be opened and closed to
activate or deactivate the separation devices 266, 266a, 266b, and
thereby adjust the purity of the gas discharged from the device
266.
[0415] In some embodiments, the back pressure regulator valve 233
(FIG. 7) can be adjusted to adjust the flow rate of exhaust gas
through the system 210. Optionally, further purity control can be
achieved by adjusting the speed of the engine 220. For example, the
speed of the engine 220 can be reduced, thereby lowering the
volumetric flow rate of exhaust gases out of the engine 220 and the
amount of ambient air mixed into the mixing plenum 229 can be
reduced such that more exhaust gas is delivered to the compressor
246. As such, the oxygen content of the exhaust gas will be lower
and thus a higher level of "purity" can be obtained. Additionally,
other adjustments can be made to the system 210 to achieve the
desired flow rate, output pressure, and purity. For example, as
noted above, the valve 322 can also be adjusted to change the
output pressure and purity of the gas discharged from the
system.
Well Construction
[0416] The systems 200, 200A, 200B can also be used during the
construction of a well. For example, as is known in the art, a dry
inert gas is desirable for assisting drilling operations of
vertical and horizontal wells. For example, nitrogen gas can be
added to a drilling mud when a drill string is being used to drill
a new well. Additional nitrogen gas can be added if a drill string
becomes stuck during drilling because of lost or reduced
circulation or low pressure zones or when more velocity is required
to lift drill cuttings from the well bore.
[0417] When the drill string has cut the well to the desired or
"critical" depth, a casing pipe is typically cemented into place to
protect the well bore. During this process, nitrogen can be used to
assist the cementing process. For example, nitrogen can be added to
the cement as the cement is pumped into the casing and returned
back up the annulus, creating a bond between the well bore and the
casing outside protecting the well bore. This process can be used
when the cement hydrostatic pressure is higher than the well bore
pressure, which in turn could cause lost or reduced circulation and
loss of cement height required to protect the well bore in
segregated zones. During such construction processes, nitrogen can
be supplied up to about 5,000 standard cubic feet per minute (scfm)
at pressures up to about 5,000 psi. Such cementing procedures are
described above with reference to FIGS. 1-4.
[0418] With the systems 200, 200A, 200B, or other similar systems,
the purity of the inert gas discharged from these systems 200,
200A, 200B can be adjusted to be about 95% or higher. Additionally,
the booster compressor 330 or an additional booster compressor may
be used to inject the gas discharged from the separation unit 266,
266' into the well or cementing system.
[0419] As noted above, during these procedures, the purity of the
gas discharged from the separation unit 266, 266', can be adjusted
by adding or deleting active membranes, as described above with
reference to FIG. 7H. Additionally, the purity of the gas
discharged from the systems 210, 210', can be adjusted by adjusting
the flow rate of the exhaust gas through the separation units 266
by adjusting the back pressure regulator valve 233. Further purity
control can be achieved by adjusting the speed of the engine 220
and/or the compressor 246. Additionally, as noted above, the valve
322 can also be adjusted to change the output pressure and purity
of the gas discharged from the system.
Under Balanced Drilling (UBD)
[0420] Dry inert gas, such as nitrogen gas, is commonly used to
assist drilling for hydrocarbons in vertical and in horizontal
wells where the well bore pressure is lower than the hydrostatic
pressure of the drilling mud used during drilling. For example,
nitrogen gas can be added to the drilling mud at a rate required to
reduce the hydrostatic pressure of the well bore to reduce losses
of hydrocarbon to the bearing zone around the bore or to allow the
hydrocarbon bearing zone to produce hydrocarbons during drilling.
Further, using a gas such as nitrogen gas to reduce the hydrostatic
pressure of the mud can help drilling through lost or lowered
circulation zones or to increase the rate of penetration (ROP) of
the drilling process.
[0421] The drilling mud flow rate can produce enough velocity and
volumetric flow to return drill cuttings back to the surface. In
some applications, the drilling mud or fluid may be nitrogen gas
alone pumped at a rate sufficient to carry drill cuttings upwardly
to the surface. This flow rate could be as high as about 5,000
standard cubic feet per minute at pressures up to about 5,000
psi.
[0422] Drilling of such wells can be performed using a drill string
and bit rotated by surfaced equipment and/or the use of a down hole
positive displacement motor (PDM). Such drill strings can be
conventional jointed pipes deployed with a conventional drilling
rig, a hydraulic work over rig, or a coil tubing strings deployed
with an injector system.
[0423] Using the systems 200, 200A, 200B, or a similar system,
lower discharge pressures can be used, for example, pressures from
about 15 to 350 psig. Thus, the booster compressor 330 can be shut
down or otherwise not used for these types of applications.
Additionally, for underbalanced drilling, nitrogen purities at
about 95% or higher can be used. However, there are other
applications where higher purities are recommended. For example,
but without limitation, where the well contains certain sensitive
chemicals such as H.sub.2S, also known as "sour gas," higher purity
nitrogen should be used, for example, up to about 99.5% nitrogen,
due to the corrosive effects of the sour gas on the drill
string.
[0424] As in other applications, the nitrogen purity can be
adjusted in several different ways. For example, with reference to
FIG. 7H, the number of separation units 266, 266a, 266b can be
adjusted by operating the valves noted above. Further, the flow
rate of exhaust gas directed to the separation device 266 can be
adjusted by adjusting the back pressure regulator valve 233.
Additionally, the speed of the engine 220 and/or the speed of the
compressor 246 can be adjusted to adjust the volume of exhaust gas
directed to the separation unit 266. As noted above, the valve 322
can also be adjusted to change the output pressure and purity of
the gas discharged from the system.
[0425] In under balanced drilling operations where higher pressures
are desired, such as pressures above 350 psig, the booster
compressor 330 can be operated to raise the pressure. For example,
the booster compressor 330 can be set to raise the pressure of the
gas discharged from the separation unit 266 up to about 5,000
psig.
Well Bore Maintenance
[0426] Well bore maintenance procedures often incorporate an inert
dry gas. For example, after a well has been constructed and
completed, the well will start to produce hydrocarbons. From time
to time, the well may require maintenance if production starts to
decrease.
[0427] For example, the well bore may benefit from being cleaned
out, stimulated, or gas lifted. In these procedures, nitrogen gas
is often injected alone or with other fluids through the completion
string, a jointed tubing, or coil tubing, back to the surface so as
to lift out debris such as sand, water, sludge, organic matter, or
scale. This procedure restores the flow rate of hydrocarbons into
and up through the well bore.
[0428] Occasionally, well bores may also need stimulation to start
or restart the flow of hydrocarbons or to maintain hydrocarbon
production. Such stimulation techniques can include acidizing,
chemical treatments, fracturing, or gas lifting. In these
procedures, nitrogen gas can be used to flush out the stimulation
fluids noted above and return them back to the surface. For
example, the nitrogen can be used to reduce the hydrostatic
pressure of the stimulation fluids used and to creating energy in
the well bore to push these fluids back to the surface. Flow rates
of the nitrogen gas can be as high as about 5,000 standard cubic
feet per minute at pressures up to about 5,000 psi.
[0429] The systems 200, 200A, 200B can be used to perform these
types of well bore maintenance procedures. Typically, nitrogen gas
at a purity of about 95% or higher can be used.
[0430] As noted above, the purity of the nitrogen gas discharged by
the systems 200, 200A, 200B can be adjusted by adding or deleting
membrane units 266, adjusting the flow rate of exhaust gas through
the separation devices 266, or by adjusting a back pressure
regulator valve 233. Optionally, the purity can also be affected by
adjusting the speed of the engine 220 and/or the compressor 246. As
noted above, the valve 322 can also be adjusted to change the
output pressure and purity of the gas discharged from the
system.
Enhanced Oil (and/or Gas) Recovery (EOR)
[0431] After a well has produced for a significant amount of time,
large voids can be left behind within the producing formation and
additionally, the pressure within the formation can be reduced over
time. Thus, nitrogen gases can be used to fill the voids left
behind and to increase the pressure of the formation.
[0432] As such, the production from the formation and the life of
the field itself can be improved. For example, nitrogen gas or
other inert gases can be injected directly into the void spaces, an
injection well can be drilled into the same formation through which
the gas can be injected, or additional formation pressure can be
generated through other artificial means to enhance the production
from the well.
[0433] Additionally, nitrogen gas or other inert gases can be used
to enhance oil and gas recovery by injection into an injection
string or gas lift mandrel in the production string. For example,
nitrogen gas can be continuously added to the production to reduce
the hydrostatic pressure and thereby increase the velocity of the
hydrocarbon, even though the formation pressure has decreased below
a critical flow pressure point.
[0434] In using the systems 200, 200A, 200B, or other similar
systems, nitrogen gas can be generated at about 95% or higher
purity and the booster compressor 330 can also be used. As noted
above, the purity of the nitrogen can be adjusted by adding or
deleting separation units (FIG. 7H), by adjusting the flow of
exhaust gas through the separation units 266, and/or adjusting a
back pressure regulator valve 233. Additionally, the purity of the
discharged gas can be controlled by changing the speed of the
engine 220 and/or the speed of the compressor 246. As noted above,
the valve 322 can also be adjusted to change the output pressure
and purity of the gas discharged from the system. In these
applications, the flow rates for nitrogen gas can be as high as
about 5,000 standard cubic feet per minute and up to pressures of
about 5,000 psi.
Pipeline Purging, Drying, and Pressure Testing
[0435] In applications such as pipeline purging, drawing, and
pressure testing, an inert dry gas is often used to displace
chemicals, volatile materials, or moisture within plant processing
systems or operating pipelines. For example, an inert dry gas, such
as nitrogen, can be used to directly displace such fluids out of
the pipes or to push a "pig" or other internal plug to displace the
materials remaining in the piping or pipeline. Dry nitrogen is a
preferred gas for its flame retardant properties and its inert
nature.
[0436] The pigs noted above can also be used to scrape the pipeline
in preparation for inspection, corrosion treatment, or pressure
testing. It is often desirable that moisture is removed from such
pipelines as well. Thus, in these applications, it is desirable to
use an inert gas with a low dew point (e.g. -40.degree. F. or
lower) to achieve a sufficiently fast drawing of the pipeline.
Further, hot dry gases also accelerate the drying process.
[0437] In using the system 200, 200A, 200B, or other similar
systems for pipeline purging, drying, and/or pressure testing, the
systems 200, 200A, 200B can be operated at lower pressures, for
example, but without limitation, about 15 to about 350 psig. Thus,
in such applications, the booster compressor 330 is not
required.
[0438] Typically, for these types of applications, the gas
generated by the systems 200, 200A, 200B can be a nitrogen gas at
about 95% or higher purity. Some applications require higher
purities. For example, in catalyst regeneration applications in
which an oxygen sensitive catalyst is being removed or replaced, it
is desirable to use nitrogen gas of at least about 99% or higher
purity.
[0439] In applications where very low dew points are desired,
higher purity is advantageous because the higher the nitrogen
purity, the lower the dew point of the gas. Thus, higher purity
nitrogen gas is desirable for low dew point applications. Further,
in applications where other sensitive chemicals are present, a
higher nitrogen purity, such as about 99.5% nitrogen or higher, may
be desirable.
[0440] As noted above, the purity of the nitrogen discharged from
the systems 200, 200A, 200B can be adjusted by adding or deleting
membranes 266, or adjusting the flow of exhaust gas through the
separation devices 266 by adjusting a back pressure regulator valve
233. The purity of the nitrogen gas can also be adjusted by
changing the speed of the engine 220 and/or the speed of the
compressor 246 so as to change the volume of exhaust gas directed
to the separation units 266. As noted above, the valve 322 can also
be adjusted to change the output pressure and purity of the gas
discharged from the system. Optionally, a dew point analyzer device
(not shown) can be included in either of the systems 200, 200A,
200B to provide a reading on the dew point of the gas discharged
from the systems 200, 200A, 200B.
[0441] As described above with reference to FIG. 7, the systems
200, 200A, 200B can also include the bypass 392 for directing the
gases discharged from the separation unit 266 to a heating device
397. This bypass 392 allows the discharge gas to be reheated
through heat from the exhaust gas from the engine 220. However,
other heaters can also be used.
[0442] For such applications, preferably, the systems 200, 200A,
200B can include inlet and outlet pressure gauges, temperature
gauges, etc., and these parameters can be used to trigger safety
alarms and for controlling shut down protocols. Additionally, fluid
flow meters can also be provided at various points in the systems
200, 200A, 200B, including the inlets and outlets therefrom.
[0443] For applications requiring higher pressures, such as
pneumatic testing, relief valve testing, or other applications
requiring pressures above 350 psig (for example, up to about 5,000
psig), the booster compressor 330 can be used to raise the fluid
discharged from the separation unit 266 up to such pressures. In
applications where it is desired to raise the temperature of high
pressure fluid, i.e., fluid discharged from the booster compressor
330, the fluid can be directed through the bypass line 395 to flow
through the bypass 392 to the heater 397.
Shipboard Inerting of Chemical and Oil Tankers
[0444] As is known in the art, maritime regulations require certain
chemical tankers, crude oil tankers, and liquid natural gas (LNG)
tankers to have a "pad" of inert gas within the cargo tanks. The
"pad" is used to reduce the concentration of oxygen such that there
is insufficient oxygen to support combustion. For example,
typically, it is required that there is less than 8% and as low as
0.5% oxygen in such storage tanks depending on the safety factors
applied in the particular commercial practice.
[0445] The inert gas can also be used to pressurize chemical tanks
as they are unloaded, for example, to replace the void created
within the tank as the desired fluid is removed from the tank. As
such, the inert gas provides a constant positive pressure of inert
gas within the filled tank which prevents venting and contamination
by the ingress of air that might have been drawn into the void.
[0446] As noted above, flue gas systems can use combustion of
hydrocarbon fuels and air to generate low oxygen gases. However,
these systems also generate high percentages of carbon dioxide
(typically over 10%) which is a normal product of combustion. Thus,
such high carbon dioxide content exhaust gases may not be
appropriate for tanks containing chemicals that react with carbon
dioxide. Additionally, carbon dioxide can be acidic in the pressure
of moisture.
[0447] Thus, flue gas from combustion sources are not always
acceptable as a "padding gas" even though it may be considered to
be generally inert. In applications where flue gas can be used,
some known flue gas systems have supplemental "gas topping" inert
gas generators and compressors that operate at positive pressures
because flue gas pressure is usually too low to properly pressurize
cargo tanks.
[0448] In using either of the systems 200, 200A, 200B, or other
similar systems for shipboard inerting, nitrogen gas of a desirable
purity can be used for all of these applications. Additionally,
because the systems 200, 200A, 200B are configured to deal with the
normal contaminants from fuel air combustion, the systems 200,
200A, 200B can also accept exhaust gases from other systems.
[0449] For example, as noted above, the source 390 (FIG. 7) can be
an exhaust system of a shipboard engine. As described in detail
above, the filtration unit 251 is configured to deal with the
typical types of contaminants found in exhaust gases from air/fuel
combustion engines. Additionally, the systems 200, 200A, 200B can
also operate using only the exhaust gases from the engine 220 or a
mix of atmospheric air and the exhaust gas from the engine 220.
Optionally, the systems 200, 200A, 200B can operate on a mix of
ambient atmospheric air, the exhaust gas from the engine 220,
and/or other flue or exhaust gases from the source 390.
[0450] As noted above, the filtration unit 251 can be configured to
remove carbon dioxide, sulfur, oxides of nitrogen, and other
contaminants. Thus, the systems 200, 200A, 200B can utilize flue
gases that are plentiful and available on ships and use those
gases, after being passed through the filtration unit 251, in
applications for which flue gas has previously been
unacceptable.
[0451] As noted above, the purity of the nitrogen gas discharged
from the systems 200, 200A, 200B can be adjusted by activating or
deactivating separation units within the separation unit 266,
adjusting the flow rate of the exhaust gas from the engine 220 by
adjusting the back pressure regulator valve 233. Optionally, the
flow of exhaust gas can also be changed by adjusting the speed of
the engine 220 and/or the speed of the compressor 246. As noted
above, the valve 322 can also be adjusted to change the output
pressure and purity of the gas discharged from the system.
[0452] The systems 200, 200A, 200B can produce an inert gas that is
relatively dry, e.g., with water content in the parts per million
range. Most currently available flue gas systems cannot generate
useable gases with such a low moisture content. Because of the low
flow and pressure requirements for cargo tank padding, higher
pressure storage tanks on a ship can be filled with the systems
200, 200A, 200B, either on the ship or at a terminal. Thus, the
high capacity high pressure storage tanks can eliminate the need
for an onboard gas generator system, even eliminating the need for
flue gas systems currently used. Further, the dry nitrogen gas
produced by the systems 200, 200A, 200B can also be used for
instrument air or other shipboard requirements.
[0453] The various methods and techniques described above provide a
number of ways to carry out the disclosed embodiments. Of course,
it is to be understood that not necessarily all objectives or
advantages described may be achieved in accordance with any
particular embodiment described herein. Thus, for example, those
skilled in the art will recognize that the methods may be performed
in a manner that achieves or optimizes one advantage or group of
advantages as taught herein without necessarily achieving other
objectives or advantages as may be taught or suggested herein.
[0454] Furthermore, the skilled artisan will recognize the
interchangeability of various features from different embodiments
disclosed herein. Similarly, the various features and steps
discussed above, as well as other known equivalents for each such
feature or step, can be mixed and matched by one of ordinary skill
in this art to perform methods in accordance with principles
described herein. Additionally, the methods described and
illustrated herein are not limited to the exact sequence of acts
described, nor are they necessarily limited to the practice of all
of the acts set forth. Other sequences of events or acts, or less
than all of the events, or simultaneous occurrence of the events,
may be utilized in practicing the embodiments of the
inventions.
[0455] Although the inventions have been disclosed in the context
of certain embodiments and examples, it will be understood by those
skilled in the art that the inventions extend beyond the
specifically disclosed embodiments to other alternative embodiments
and/or uses and obvious modifications and equivalents thereof.
Accordingly, the inventions are not intended to be limited by the
specific disclosures of preferred embodiments herein.
* * * * *