U.S. patent application number 13/555122 was filed with the patent office on 2013-03-28 for methods and systems for heating and manipulating fluids.
The applicant listed for this patent is F. ALAN FRICK. Invention is credited to F. ALAN FRICK.
Application Number | 20130075245 13/555122 |
Document ID | / |
Family ID | 47910043 |
Filed Date | 2013-03-28 |
United States Patent
Application |
20130075245 |
Kind Code |
A1 |
FRICK; F. ALAN |
March 28, 2013 |
METHODS AND SYSTEMS FOR HEATING AND MANIPULATING FLUIDS
Abstract
Systems and methods are provided for heating and manipulating a
fluid to heat the fluid, evaporate water from the fluid,
concentrate the fluid, separate the fluid into fractions; and/or
pasteurize the fluid, comprising a closed-loop heating subsystem
coupled to a primary fluid-to-fluid heat exchanger, and one or more
fluid manipulation subsystems also coupled to the primary
fluid-to-fluid heat exchanger.
Inventors: |
FRICK; F. ALAN; (HOUSTON,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FRICK; F. ALAN |
HOUSTON |
TX |
US |
|
|
Family ID: |
47910043 |
Appl. No.: |
13/555122 |
Filed: |
July 21, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13467551 |
May 9, 2012 |
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13555122 |
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13069363 |
Mar 22, 2011 |
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13467551 |
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12638984 |
Dec 16, 2009 |
8371251 |
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13069363 |
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13069363 |
Mar 22, 2011 |
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12638984 |
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12638984 |
Dec 16, 2009 |
8371251 |
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13069363 |
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12638984 |
Dec 16, 2009 |
8371251 |
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12638984 |
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61510485 |
Jul 22, 2011 |
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61510485 |
Jul 22, 2011 |
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Current U.S.
Class: |
203/22 ;
202/185.1; 202/185.3 |
Current CPC
Class: |
B01D 5/006 20130101;
B01D 1/16 20130101; C02F 1/12 20130101; B01D 1/0058 20130101; F01K
27/02 20130101; B01D 3/007 20130101; C02F 1/16 20130101; Y02E 20/30
20130101; B01D 3/06 20130101; B01D 1/0047 20130101; F22B 1/1807
20130101 |
Class at
Publication: |
203/22 ;
202/185.1; 202/185.3 |
International
Class: |
B01D 1/00 20060101
B01D001/00 |
Claims
1. A method of concentrating a fluid, comprising: providing a
closed-loop heating subsystem comprising a thermal energy device, a
fluid circulation pump, a first path through a fluid-to-fluid heat
exchanger, all configured to heat and circulate a first fluid to
less than its atmospheric boiling point; providing a fluid
concentrating subsystem comprising a flash tank, a second path
through the fluid-to-fluid heat exchanger and a condensing heat
exchanger; pumping a second fluid through the second path in the
fluid-to-fluid heat exchanger; transferring heat from the first
fluid to the second fluid in the fluid-to-fluid heat exchanger;
flashing the second fluid into its liquid and vapor phases in the
flash tank to evaporate at least a portion of water from the second
fluid; drawing the second fluid vapor from the flash tank into the
condensing heat exchanger to condense the vapor to liquid by
transferring heat from the vapor; and removing a portion of the
liquid phase from the flash tank as concentrated fluid when a
pre-determined property of the liquid phase is reached.
2. The method of claim 1, wherein the thermal energy device is
selected from the group consisting of: a direct-fired,
hydrocarbon-fueled boiler; a rotary heating device driven by an
internal combustion engine; and a Diesel-Electric generator set
powering an electric boiler.
3. The method of claim 2, further comprising: operating the flash
tank at less than atmospheric pressure.
4. The method of claim 2, further comprising: preheating the second
fluid by transferring heat from the concentrated fluid.
5. The method of claim 2, wherein the condensing heat exchanger is
a fluid-to-fluid condensing heat exchanger and further comprising:
providing a retention area holding a quantity of the second fluid;
extracting a portion of the second fluid from the retention area to
be pumped to the fluid-to-fluid heat exchanger; and using another
portion of the second fluid in the retention area to cool the vapor
phase in the condensing heat exchanger.
6. The method of claim 2, comprising operating the condensing heat
exchanger at less than atmospheric pressure.
7. The method of claim 2, wherein the second fluid is diluted
completion fluid and the concentrated fluid is a completion
fluid.
8. The method of claim 2, wherein the second fluid is produced
water and the concentrated fluid is a concentrated brine
solution.
9. The method of claim 2, further comprising: withdrawing a portion
of the liquid phase from the flash tank; determining a property of
the withdrawn liquid phase; and mixing the withdrawn liquid phase
with the incoming second fluid.
10. The method of claim 9, further comprising: using the property
determined from the withdrawn liquid to control the removal of the
portion of the liquid phase from the flash as concentrated
fluid.
11. The method of claim 2, wherein the condensing heat exchanger is
an air-to-fluid condensing heat exchanger.
12. A fluid concentrating system, comprising: a closed-loop heating
subsystem comprising a thermal energy device, a fluid circulation
pump, a first path through a fluid-to-fluid heat exchanger, all
configured to heat and circulate a first fluid to less than its
atmospheric boiling point; a fluid concentrating subsystem
comprising: a second path through the fluid-to-fluid heat
exchanger; a pump for pumping a second fluid through the second
path in the fluid-to-fluid heat exchanger to transfer heat from the
first fluid to the second fluid in the fluid-to-fluid heat
exchanger; a flash tank having an orifice through which the heated
second fluid is flashed into its liquid and vapor phases to
evaporate at least a portion of water from the second fluid;, a
condensing heat exchanger to condense vapor withdrawn from the
flash tank to liquid by transferring heat from the vapor; and an
extraction system for removing a portion of the liquid phase from
the flash tank as concentrated fluid when a pre-determined property
of the liquid phase is reached.
13. The system of claim 12, wherein the thermal energy device is
selected from the group consisting of: a direct-fired,
hydrocarbon-fueled boiler; a rotary heating device driven by an
internal combustion engine; and an Diesel-Electric generator set
powering an electric boiler.
14. The system of claim 13, further comprising: A vacuum system to
operate the flash tank at less than atmospheric pressure.
15. The system of claim 13, further comprising: a fluid-to-fluid
preheating heat exchanger for preheating the second fluid by
transferring heat from the extracted concentrated fluid to the
incoming second fluid.
16. The system of claim 13, further comprising: a retention area
holding a quantity of the second fluid; and wherein the condensing
heat exchanger is a fluid-to-fluid condensing heat exchanger for
transferring heat from the vapor to portion of the second fluid
from the retention area.
17. The system of claim 13, further comprising a vacuum system for
operating the condensing heat exchanger at less than atmospheric
pressure.
18. The system of claim 13, wherein the second fluid is diluted
completion fluid and the concentrated fluid is a completion
fluid.
19. The system of claim 13, wherein the second fluid is produced
water and the concentrated fluid is a concentrated brine
solution.
20. The system of claim 13, further comprising: a liquid phase flow
path between the liquid phase in the flash tank and a second fluid
inlet to the fluid-to-fluid heat exchanger; a device for
determining a property of the liquid phase in the liquid phase flow
path.
21. The system of claim 20, further comprising: a control signal
from the property-determining device to the extraction pump to
control the removal of the portion of the liquid phase from the
flash tank as concentrated fluid when the determined property
reaches a desired value.
22. The system of claim 13, wherein the condensing heat exchanger
is an air-to-fluid condensing heat exchanger.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This continuing application is based on, claims priority to,
and benefit of the following applications and patents, the entire
contents of each of which are incorporated herein by reference for
all purposes:
[0002] U.S. Provisional Application No. 61/510,485, filed on Jul.
22, 2011 (pending).
[0003] U.S. Non-Provisional application Ser. No. 13/467,551, filed
on May 9, 2012 (pending), which claims priority to U.S. Provisional
Application 61/510,485, filed on Jul. 22, 2011 (pending) and U.S.
Provisional Application 61/484,210, filed on May 9, 2011 (expired);
and which is a continuation-in-part of U.S. Non-Provisional
application Ser. No. 13/069,363 filed on Mar. 22, 2011 (pending);
and a continuation-in-part of U.S. Non-Provisional application Ser.
No. 12/638,984, filed on Dec. 16, 2009 (pending).
[0004] U.S. Non-Provisional application Ser. No. 13/069,363, filed
on Mar. 22, 2011 (pending), which claims priority to U.S.
Provisional Application 61/316,362, filed on Mar. 22, 2010
(expired); and which is a continuation-in-part of U.S.
Non-Provisional application Ser. No. 12/638,984 filed on Dec. 16,
2009 (pending).
[0005] U.S. Non-Provisional application Ser. No. 12/638,984 filed
on Dec. 16, 2009 (pending), and which is a continuation-in-part of
U.S. Non-Provisional application Ser. No. 12/615,331 filed on Nov.
10, 2009 (abandoned); a continuation-in-pat application of U.S.
Non-Provisional application Ser. No. 11/934,645 filed on Nov. 2,
2007 (abandoned); a continuation-in-part application of U.S.
Non-Provisional application Ser. No. 11/764,270 filed on Jun. 18,
2007 (abandoned); a continuation-in-part application of U.S.
Non-Provisional application Ser. No. 11/748,475 filed on May 14,
2007, now U.S. Pat. No. 7,614,367, issued on Nov. 10, 2009; a
continuation application of U.S. Non-Provisional application Ser.
No. 11/741,570 filed on Apr. 27, 2007 (abandoned); and a
continuation-in-part application of U.S. Non-Provisional
application Ser. No. 11/738,644, filed on Apr. 23, 2007
(abandoned); and which claims priority to U.S. Provisional
Application Ser. No. 61/249,841 filed on Oct. 8, 2009 (expired);
U.S. Provisional Application Ser. No. 60/883,178 filed on Jan. 3,
2007 (expired); U.S. Provisional Application Ser. No. 60/864,160
filed on Nov. 2, 2006 (expired); U.S. Provisional Application Ser.
No. 60/800,495 filed on May 15, 2006 (expired); U.S. Provisional
Application Ser. No. 60/795,983 filed on Apr. 28, 2006 (expired);
and U.S. Provisional Application Ser. no. 60/749,413, filed on Apr.
24, 2006 (expired).
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0006] Not applicable.
REFERENCE TO APPENDIX
[0007] Not applicable.
BACKGROUND OF THE INVENTION
[0008] 1. Field of the Invention
[0009] The inventions disclosed herein relate generally to systems
and their use for manipulating fluids, and relate specifically to
heating, evaporating, condensing, separating, sterilizing and/or
otherwise manipulating fluids, including, but not limited to,
industrial fluids associated with the oil and gas industries.
[0010] 2. Description of the Related Art
[0011] Industrial operations, such as, but not limited to, oilfield
operations, oftentimes require sources of heat for a variety of
purposes, such as heating a fluid, evaporating a component from a
fluid, condensing a fluid, separating a fluid according to its
properties, and/or sterilizing or killing objectionable organisms
in a fluid. In the past, industry has looked to both open flame (or
direct fired) and flameless systems to provide the thermal energy
for such systems.
[0012] For example, U.S. Pat. No. 7,424,916 B2 entitled "Flameless
Hot Oiler" is said to describe "[a] flameless heating system
comprising: at least one engine, each engine including a coolant
for removing heat from the engine and each engine producing
exhaust; a loading means for loading the engine; a heat exchange
system, the heat exchange system comprising: a heat exchange fluid;
a pump for circulating the heat exchange fluid; at least one heat
exchanger for transferring heat from the at least one engine
coolant to the heat exchange fluid; and an exhaust heat exchanger
for transferring heat from the exhaust of the at least one engine
to the heat exchange fluid; a batch fluid; and a heat exchanger for
transferring heat from the heat exchange system to the batch fluid,
wherein heat is transferred from the engine to the heat exchange
system, and from the heat exchange system to the batch fluid."
[0013] U.S. Pat. No. 5,279,262 entitled "Mechanical Liquid
Vaporizing Waterbrake" is said to describe "[a] water brake which
uses mechanical power to kinetically heat water to vapor or steam,
and use thereof as a steam generator or cooling water conserving
dynamometer or motion retarder. In the simplest embodiment, radial
impeller vanes (5b) throw water against stator vanes (6e), whence
the water rebounds to the impeller (5). The peripheral rebounding
movement continues back and forth. Power dissipates as heat in the
water causing the water to increase in temperature and to vaporize.
The vapor, being lower in density and viscosity than is the water,
flows to and out a central outlet (9) while the denser water is
centrifugally separated from the vapor and retained in the
peripheral rebounding motion. Water leaving as vapor is continually
replaced through a cooling water inlet (8), allowing continuous
operation over wide ranges of speed, torque, power and steam
generation rates, both at steady state and at controlled rates of
change."
[0014] U.S. Pat. No. 4,264,826 entitled "Apparatus For Generating
Thermal Energy And Electrical Energy" is said to describe "[a]n
apparatus for generating thermal and electrical energy includes an
internal combustion engine connected to and adapted to drive a
generator for providing electrical power and a brake for generating
thermal energy. In one embodiment, a heat carrier flows through
appropriate conduits for absorbing heat energy from the brake, from
the combustion chamber of the engine, and from the engine exhaust
gases and delivers the heat energy to a end-use heat exchanger, for
example, a room or space heater. In a second embodiment, the engine
exhaust gas flow is used to drive a gas turbine that, in turn,
drives a compressor in a thermal cycle to provide additional heat
transfer capability."
[0015] U.S. Patent Application Publication No. 2006/0185621 A1,
published on Aug. 24, 2006 and entitled "Flameless Boiler," is said
to describe "[a] flameless boiler comprising generator means for
generating heat in fluid circulated there through by shearing of
the fluid; a prime mover drivingly connected to the generator means
for shearing of the fluid; a supply reservoir for the fluid; a
first pump for circulating the fluid from the supply reservoir to
the generator means; and a pressure vessel in fluid communication
with the generator means for receiving heated fluid there from, the
pressure vessel having an outlet for drawing steam therefrom."
[0016] U.S. Patent Application Publication No. 2005/0224223 A1,
published on Oct. 13, 2005 and entitled "Heating Apparatus for
Wells," is said to describe "[a]n apparatus for warming objects
such as production conduits at a well site comprises an internal
combustion engine driving a well pump. A heat exchanger shell is
connected to an exhaust port of the engine, and has an output port.
A circulating pump is driven by the engine, and a heating circuit
is connected to the circulating pump such that liquid in the
heating circuit is pumped from a pump output of the circulating
pump through the heating circuit to a pump intake of the
circulating pump. The heating circuit comprises a heat absorbing
portion inside the heat exchanger shell arranged such that heat
from the exhaust of the engine is transferred to the liquid
therein, and a heating conduit arranged adjacent to a production
conduit or other desired object such that heat from the liquid in
the heating conduit is transferred to the object."
[0017] The present disclosure is directed to improved systems and
methods for heating and/or manipulating a fluid.
BRIEF SUMMARY OF THE INVENTION
[0018] As a brief summary of the inventions disclosed herein, and
without limitation, I have invented methods and systems for
manipulating a heated fluid. My inventions include heating systems
or subsystems in which a thermal energy source is used to heat a
fluid in opened-loop arrangement or closed-loop arrangement. The
thermal energy source may comprise a direct fired or open flame
boiler, an internal combustion engine driving a rotary heating
device, or an internal combustion engine powering an electric
boiler. The heating system may be operated at a desired temperature
and may be operated at less than atmospheric pressure, atmospheric
pressure or may be pressurized. Various plumbing, pumping and
control systems are disclosed for the various heating systems
taught herein.
[0019] As a brief summary of the inventions disclosed herein, and
without limitation, my inventions also include methods and systems
for evaporating a fluid, such as water. These systems and methods
may utilize any of the heating subsystems disclosed herein as a
source of thermal energy to effect evaporation, and a
fluid-to-fluid heat exchanger to transfer heat between the heating
systems or subsystem and the evaporation subsystem. The evaporation
systems may comprise a flash tank for separating the fluid into its
vapor and liquid phases and a condensing heat exchanger for
condensing the vapor to liquid. Single and multiple effect
evaporation systems are disclosed. Various plumbing, pumping,
measuring and control systems are disclosed for the various
evaporation systems and subsystems taught herein.
[0020] As a brief summary of the inventions disclosed herein, and
without limitation, my inventions also include methods and systems
for concentrating a fluid. These systems and methods may utilize
any of the heating systems or subsystems disclosed herein as a
source of thermal energy to effect concentration, and a
fluid-to-fluid heat exchanger to transfer heat between the heating
subsystem and the concentration subsystem. The concentration
systems may comprise a flash tank for separating the fluid into its
vapor and liquid phases and a condensing heat exchanger for
condensing the vapor to liquid. Extraction systems are disclosed
for removing concentrated liquid from the flash tank. Various
plumbing, pumping, measuring and control systems are disclosed for
the various concentrating systems or subsystems taught herein.
[0021] As a brief summary of the inventions disclosed herein, and
without limitation, my inventions also include methods and systems
for separating a fluid into its fractional or property-based
components. These systems and methods may utilize any of the
heating systems or subsystems disclosed herein as a source of
thermal energy to effect concentration, and a fluid-to-fluid heat
exchanger to transfer heat between the heating subsystem and the
separating subsystem. The separating systems may comprise a
separation tower for separating the fluid into its fractional
components and a condensing heat exchanger for condensing fluid
vapors. Various plumbing, pumping, measuring and control systems
are disclosed for the various separating systems and subsystems
taught herein
[0022] As a brief summary of the inventions disclosed herein, and
without limitation, my inventions also include methods and systems
for pasteurizing a fluid. These systems and methods may utilize any
of the heating systems or subsystems disclosed herein as a source
of thermal energy to effect pasteurization, and a fluid-to-fluid
heat exchanger to transfer heat between the heating subsystem and
the pasteurizing subsystem. The pasteurizing systems may comprise a
flash tank for separating the fluid into its vapor and liquid
phases and a condensing heat exchanger for condensing the vapor to
liquid. Extraction systems are disclosed for removing pasteurized
liquid from the flash tank. Various plumbing, pumping, measuring
and control systems are disclosed for the various pasteurizing
systems or subsystems taught herein.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0023] The Figures described below are provided as an aid to
understanding the written descriptions provided herein of my
inventions. Neither the Figures nor the written descriptions
thereof are intended to limit the scope of the appended claims.
Rather, the Figures and written descriptions are provided to
illustrate the inventive concepts to a person of skill in the art
and to enable such person to make and use the inventive
concepts.
[0024] FIG. 1 illustrates an opened-loop fluid heating system
utilizing a rotary heating device.
[0025] FIG. 2 illustrates a closed-loop fluid heating utilizing a
rotary heating device.
[0026] FIG. 3 illustrates another embodiment of a closed-loop fluid
heating system utilizing a rotary heating device.
[0027] FIG. 4 illustrates yet another embodiment of a closed-loop
fluid heating system utilizing a rotary heating device.
[0028] FIG. 5 illustrates still another embodiment of a closed-loop
fluid heating system utilizing a rotary heating device
[0029] FIG. 6A illustrates a closed-loop fluid heating system
utilizing a direct-fired boiler.
[0030] FIG. 6B illustrates a closed-loop fluid heating system
utilizing a Diesel genset.
[0031] FIG. 7 illustrates an opened-loop fluid evaporating system
utilizing a rotary heating device.
[0032] FIG. 8 illustrates another embodiment of a fluid evaporating
subsystem.
[0033] FIG. 9 illustrates a closed-loop fluid evaporating system
utilizing a rotary heating device.
[0034] FIG. 10 illustrates another embodiment of a closed-loop
fluid evaporating system utilizing a rotary heating device.
[0035] FIG. 11 illustrates yet another embodiment of a closed-loop
fluid evaporating system utilizing a rotary heating device.
[0036] FIG. 12A illustrates a closed-loop fluid evaporating system
utilizing a direct-fired boiler.
[0037] FIG. 12B illustrates a closed-loop, multiple effect fluid
evaporating system utilizing a direct-fired boiler.
[0038] FIG. 12C illustrates a closed-loop, multiple effect fluid
evaporating system utilizing a direct-fired boiler.
[0039] FIG. 13A illustrates a fluid concentrating subsystem.
[0040] FIG. 13B illustrates a direct-fired fluid concentrating
system.
[0041] FIG. 14 illustrates a closed-loop fluid concentrating system
adapted for use on an offshore rig.
[0042] FIG. 15 illustrates another embodiment of a closed-loop
fluid concentrating system utilizing a rotary heating device.
[0043] FIG. 16 illustrates yet another embodiment of a fluid
concentrating system.
[0044] FIG. 17 illustrates an embodiment of a fluid separating or
fractionating system.
[0045] FIG. 18 illustrates another embodiment of a fluid separating
or fractionating system
[0046] FIG. 19A illustrates one of many embodiments of a
pasteurizing system for an industrial fluid.
[0047] FIG. 19B illustrates another embodiment of a pasteurizing
system for an industrial fluid utilizing a direct-fired boiler.
[0048] FIGS. 20A and 20B illustrate one of many embodiments of a
fluid heating and pumping system comprising an electric boiler and
diesel genset.
[0049] FIGS. 21A and 21B illustrate an embodiment of a system
incorporating multiple subsystems incorporating the present
inventions.
DETAILED DESCRIPTION
[0050] One or more illustrative embodiments incorporating the
inventions disclosed herein are presented below. For the sake of
clarity, not all features of an actual implementation are described
or shown. Persons of skill appreciate that in the development of an
actual embodiment incorporating aspects of the present inventions,
numerous implementation-specific decisions must be made to achieve
the developer's goals, such as compliance with system-related,
business-related, government-related and other constraints, which
vary by implementation and from time to time. While a developer's
efforts might be complex and time-consuming, such efforts would be,
nevertheless, a normal undertaking for those of ordinary skill in
the art having benefit of this disclosure.
[0051] In general terms, I have invented various systems and
methods for heating and/or otherwise manipulating a fluid.
Embodiments of my fluid heating systems may comprise opened-loop
system or a closed-loop system in which the By "opened loop," I
mean that the fluid that is desired to be manipulated is the fluid
that flows through the primary heating devices. By "closed loop," I
mean that the fluid that is desired to be manipulated flows through
a heat exchanger to pick up heat from another fluid that that flows
through the primary heating devices in closed loop arrangement. The
opened loop and closed loop systems described and illustrated
herein can batch systems or continuous systems.
[0052] One embodiment of my fluid heating and manipulating
inventions is a opened-loop system in which the fluid to be heated
flows along a plurality of heat paths. For example, one heat path
may comprise a rotary heating device coupled to a rotary kinetic
energy generator, such as, but not limited to, an internal
combustion engine, an external combustion engine or an electric
motor. The fluid may be heated in the rotary heating device and
delivered to a reservoir or accumulator. A second heat path may
comprise a fluid-to-fluid heat exchanger configured to transfer
heat from the engine's water jacket to the fluid. A third heat path
may comprise and air-to-fluid heat exchanger configured to transfer
heat from the engine's exhaust to the fluid. All three paths may be
combined to produce heated fluid. It will be appreciated that pumps
and valving can be used to control the temperature of the
fluid.
[0053] Another embodiment of my fluid heating inventions is a
closed-loop system having a first fluid-to-fluid (such as
liquid-to-liquid) heat exchanger that divides the heating system
into a primary fluid section and a secondary fluid section. The
primary fluid section may comprise a primary energy source, such as
a rotary kinetic energy generator, preferable a diesel engine. The
rotary kinetic energy is used to energize a rotary heating device.
Regardless of the primary energy source, a primary or working
fluid, such as, but not limited to, water or a water-based mixture,
is circulated through the primary energy source to thereby heat the
working fluid. In addition, all or a portion of the thermal energy
from the primary energy source may be transferred to the fluid as
well by one or more heat exchangers. A secondary, or worked, fluid
may be passed through the first heat exchanger to transfer energy
from the working fluid to the worked fluid, thereby heating the
worked fluid.
[0054] Any variety of rotary heating devices may be used for
embodiments of the inventions disclosed herein. For example, a
rotary heating device may comprise any of a number of known
devices, such as, but not limited to, a water brake, a dynamometer,
a cavitation heater (such as those disclosed in U.S. Pat. No.
7,201,225), and a shear plate or friction heater. It is preferred
that the rotary heating device for the closed-loops systems
disclosed herein an instrumented water brake (e.g., a dynamometer),
such as, but not limited to, Model TD3100 available from Taylor
Dynamometer.
[0055] Yet another embodiment of my fluid heating inventions is a
closed-loop system having a direct-fired boiler, such as a natural
gas heater, as the primary energy source. Fluid heated in the
boiler flows through a primary heat exchanger, such as a
fluid-to-fluid heat exchanger to transfer heat to the fluid to be
heated, i.e., the worked fluid. Fluid leaving the primary heat
exchanger may be accumulated in a reservoir prior to being
re-heated in the boiler. Alternately, electrical energy may be
supplied by a Diesel-Electric generator set, which is used to heat
the fluid in an electric resistance heater or boiler.
[0056] Turning now to more specific embodiments of my inventions,
FIG. 1 illustrates a flameless fluid heating system 100. The system
100 illustrated in FIG. 1 directly heats the fluid of interest,
i.e., the worked fluid. In other words, this is an "opened-loop"
design in which the fluid to be heated, such as, for example,
fracturing fluid, is passed directly through the rotary heating
device 104. In this embodiment, the rotary generator 102 is a
diesel engine of, for example, 750 hp and the rotary heater is a
Taylor Dynamometer model TD3100. Fluid enters the system 100 at
inlet 120, preferably through an appropriately sized centrifugal
pump 122, and is allowed to flow through three substantially
parallel heating paths. Adjustment of fluid flow among these paths
and, therefore, fluid temperature may be controlled by flow control
devices or valves 124a, 124b and 124c.
[0057] A first path is through valve 124a to the rotary heater 104
where torque from the engine 102 heats the fluid. The fluid leaves
the rotary heater 104 and is collected in a tank 110 that is vented
112 to atmosphere. A main circulation pump 108 draws heated fluid
from the tank 110 and returns it to system 100, generally. The tank
110 may have a fluid level control 111 adapted to control a flow
valve 118 to regulate the level of fluid inside the tank 110.
[0058] A second fluid heating path has a portion of the fluid
passing through restriction 124b and into a fluid-to-fluid heat
exchanger 114 adapted to transfer heat from the diesel engine 102,
such as from the water jacket coolant, to the worked fluid. Fluid
heated in exchanger 114 is combined with fluid from the rotary
heater 104 as illustrated in FIG. 1 A third fluid heating path has
a portion of the fluid passing through valve 124c and an
air-to-fluid heat exchanger 116, such as a finned tube heat
exchanger, adapted to transfer heat from the engine exhaust 160 to
the fluid. Heated fluid exiting the heat exchanger 116 is combined
with heated fluids from the rotary heater 104 and heat exchanger
114, with the combined heated fluid exiting the system 100 at
outlet 126. The system illustrated in FIG. 1 was designed to raise
the temperature of water by about 38.degree. F. at a flow rate of
about 280 gallons per minute.
[0059] Turning now to FIG. 2, disclosed is one of many possible
embodiments of a closed-loop fluid heating system 200. The heating
system 200 may comprise a rotary kinetic energy generator 202, a
rotary heating device 204 and a primary heat exchanger 206 all
plumbed in closed-loop fluid communication.
[0060] The rotary kinetic energy generator 202 may comprise any of
a number of rotary prime movers, such as, but not limited to
electric, pneumatic or hydraulic motors, and internal or external
combustion engines. It is preferred that rotary generator 202 be a
conventional diesel or natural gas engine, such as, for example, a
750 hp diesel engine. It will be appreciated that the amount of
horsepower generated by the prime mover 202 will control the amount
of heat generated by the system 200.
[0061] The rotary heating device 204 is preferably a water brake,
and most preferably a water brake dynamometer, such as Model TD3100
available from Taylor Dynamometer.
[0062] The output shaft 203 of the rotary generator 202 may be
coupled to the rotary heater 204 in known fashion. For example,
flex joints or other coupling mechanisms (not shown) may be used as
needed to couple the rotary generator 202 to the rotary heater 204.
One benefit of using a water brake dynamometer as the rotary
heating device is that it may be directly coupled to the flywheel
or output shaft of an internal combustion engine.
[0063] The outlet side of the rotary heater 204 may be coupled to a
reservoir or tank 210. Based on the operating characteristics of
the rotary heater 204, the tank 210 may be pressurized, evacuated
or un-pressurized. For the present embodiment using a water brake
dynamometer as the rotary heater 204, it is preferred that tank 210
be un-pressurized and vented 212 to atmosphere, thereby operating
at atmospheric conditions. A fluid circulation pump 208, such as a
centrifugal pump, is adapted to circulate or pump the fluid, i.e.
the working fluid, through the system 200.
[0064] Working fluid may be circulated from the tank 210 to a
fluid-to-fluid heat exchanger 214 adapted to transfer heat from the
rotary generator 202 to the working fluid to further heat the
fluid. For example, FIG. 2 illustrates that the engine coolant 205
from, e.g., the engine's water jacket, is used to further heat the
working fluid. It will be appreciated that heat exchanger 214 may
be in addition to or in lieu of the engine's conventional
air-to-fluid radiator. The working fluid that exits the heat
exchanger 214 may pass through another heat exchanger 216, such as
an air-to-fluid heat exchanger, to transfer energy from the
engine's exhaust gases to the working fluid. As a matter of system
design left to those of skill in the art, the engine's exhaust may
pass entirely through the heat exchanger 216, or may be apportioned
such one portion passes through the heat exchanger 216 and the
remainder passes through a conventional muffler or exhaust system
(not shown).
[0065] It will be appreciated that while FIG. 2 illustrates the
water jacket heat exchanger 214 downstream from the exhaust gases
heat exchanger 216, such orientation is not required and may be
reversed or eliminated. It is preferred;
[0066] however, that any supplement heat exchangers, such as heat
exchangers 214 and 216 be located between the discharge side of the
rotary heater 204 and the primary heat exchanger 206. Heated
working fluid is circulated from supplemental heat exchangers 214
and/or 216 to primary heat exchanger 206 and from there back to the
rotary heating device 204 to complete the closed loop.
[0067] A controllable valve or other flow restriction device 218
may be located on the inlet side of the rotary heating device 204
In the embodiment shown in FIG. 2, the valve 218 is controlled by
the water brake controller (not shown) as a function of engine 202
torque. Thus, valve 218 is controlled to load the rotary heater 204
such that the engine operates near its peak torque.
[0068] Also shown in FIG. 2 is bypass circuit 219, which may be
used to control the temperature of the fluid exiting the rotary
heating device 204. It will be appreciated that depending on the
type of rotary heating device 204 used, a backpressure valve (not
shown) between the rotary heater 204 and the tank 210 may be used
to maintain appropriate pressure on the rotary heater 204.
[0069] It will be appreciated that heating system 200 may be used
to heat fluids of all types by flowing such fluid (the "worked"
fluid) through primary heat exchanger 206 as illustrated in FIG. 2.
System 200 may be instrumented as desired, and as illustrated in
FIG. 2, several temperature transducers, T, may be beneficial. For
example, monitoring the temperature T1 of the working fluid prior
to entry into tank 210 is useful especially where the tank is
vented 212 to atmosphere. Keeping the temperature of the working
fluid below its atmospheric boiling point will prevent loss of the
working fluid to the atmosphere. It may be desired to monitor the
temperature T4 of the working fluid as it enters the rotary heater
204 and/or prior to its entry T3 into the primary heat exchanger
206. It will be appreciated that working fluid temperature T3 can
be controlled in several ways, including adjusting the flow rate of
the worked fluid through heat exchanger 206, and/or adjusting the
torque generated by the rotary generator 202, and/or adjusting the
flow or working fluid into the rotary heating device. Controllable
bypass loops (not shown) can also be established for each heating
source, such as rotary heater 204 and heat exchangers 214 and 216.
It will be appreciated that the system 200 can be used to heat a
fluid, i.e., the "worked fluid" by passing the worked fluid through
fluid-to-fluid heat exchanger 206. A flow control device 250, such
as a valve or a pump, can be used to control the temperature, T2,
of the worked fluid.
[0070] Moving on to FIG. 3, another embodiment comprising a
flameless heating system 300 is illustrated. The fluid heating
system 300 may comprise a rotary kinetic energy generator 302, a
rotary heating device 304 and a primary heat exchanger 306 all
plumbed in closed-loop fluid communication. The fluid to be heated,
or worked fluid 322, is passed through the primary heat exchanger
306 to transfer heat from the working fluid 301 to the worked fluid
322.
[0071] It is preferred that rotary generator 302 be a conventional
diesel or natural gas engine, such as, for example, a 600 hp diesel
engine and that the rotary heating device 304 be a water brake
dynamometer, such as, but not limited to, Model TD3100 available
from Taylor Dynamometer.
[0072] The output shaft 303 of the rotary generator 302 may be
coupled to the rotary heater 304 in known fashion. For example,
flex joints or other coupling mechanisms (not shown) may be used as
needed to couple the rotary generator 302 to the rotary heater 304.
One benefit of using a water brake dynamometer as the rotary
heating device 304 is that it may be directly coupled to the
flywheel or output shaft of an internal combustion engine.
[0073] The outlet side of the rotary heater 304 may be coupled to a
reservoir or tank 310. Based on the operating characteristics of
the rotary heater 304, the tank 310 may be pressurized, evacuated
or un-pressurized. For the embodiment of FIG. 3 using a water brake
dynamometer as the rotary heater 304, it is presently preferred
that tank 310 be un-pressurized and vented 312 to atmosphere,
thereby operating at atmospheric conditions. A fluid circulation
pump 308, such as a centrifugal pump, may be adapted to circulate
or pump the fluid, i.e. the working fluid, through the system
300.
[0074] The working fluid 301 may pass through a heat exchanger 316,
such as an air-to-fluid heat exchanger, to transfer energy from the
engine's exhaust gases 317 to the working fluid 301. As a matter of
system design left to those of skill in the art, the engine's
exhaust 317 may pass entirely through the heat exchanger 316, or
may be apportioned such one portion passes through the heat
exchanger 316 and the remainder passes through a conventional
muffler or exhaust system (not shown). It is preferred that exhaust
gas heat exchanger 316, and any additional or supplement heat
exchangers, be located between the discharge side of the rotary
heater 304 and the primary heat exchanger 306. Heated working fluid
301 is circulated from heat exchangers 316 to primary heat
exchanger 306 and from there back to the rotary heating device 304
to complete the closed working fluid heating loop.
[0075] A controllable valve or other flow restriction device 318
may be located on the inlet side of the rotary heating device 304
In the embodiment shown in FIG. 3, the valve 318 is controlled by
the water brake controller (not shown) as a function of engine 302
torque. Thus, valve 318 is controlled to load the rotary heater 304
such that the engine operates near it peak torque or peak
efficiency. Also shown in FIG. 3 is bypass circuit 320, which may
be used to control the temperature of the working fluid 301 exiting
the rotary heating device 304. It will be appreciated that
depending on the type of rotary heating device 304 used, a
backpressure valve (not shown) between the rotary heater 304 and
the tank 310 may be used to maintain appropriate pressure on the
rotary heater 304.
[0076] It will be appreciated that most, if not all, internal
combustion engines suitable for use with the embodiment described
in FIG. 3 will be supercharged by either an exhaust gas
supercharger (i.e., turbocharger) or a mechanical supercharger. In
either instance, the pressurized air is heated by the supercharger
to typically undesirable levels, which temperature adversely
affects the power that the engine 302 can generate. To recover some
of that waste heat and/or to increase the efficiency of the engine,
either the worked fluid 322 or the working fluid 301 may be used to
cool the supercharged air. In a preferred embodiment of the system
300 illustrated in FIG. 3, an air-to-fluid heat exchanger 332 may
be inserted into the working fluid 301 discharge line between the
primary heat exchanger 306 and the rotary heating device 304 to
transfer heat from the supercharged air to the working fluid
301.
[0077] Also shown in FIG. 3 is an optional electrical generator 324
coupled to the engine 302. For example and not limitation, the
generator 324 may be a 50 kilowatt AC generator producing 480 volt,
3 phase power for use in powering and controlling the various pumps
and instruments associated with system 300.
[0078] Alternately, the rotary heating device 304 may be replaced
with an electrically heated boiler or tank (not shown). In such
embodiment, the engine 302 would drive the electrical generator 324
or other electrical generator to provide the electrical energy for
at least the electrically heated tank. In all other material
respects, such alternate embodiment could be fashioned similarly to
the embodiment shown in FIG. 3. Thus, in this alternate embodiment,
the working fluid could be heated by at least the electrically
heated tank (not shown) and the engine exhaust 317.
[0079] It will be appreciated that the fluid heating system 300 may
be used to heat fluids of all types by flowing such fluid 322 (the
"worked" fluid) through primary heat exchanger 306 as illustrated
in FIG. 3.
[0080] In contrast to the system 200 shown in FIG. 2, system 300 of
FIG. 3 is designed to use the waste heat from the engine's 302
water jacket to preheat the worked fluid 322. As shown in FIG. 3, a
worked fluid preheat heat exchanger 326 may be used to transfer
heat from the engine coolant 328 to the worked fluid 322 before it
enters the primary heat exchanger 306. It will appreciated that
heat exchanger 326 may be in addition to or in lieu of the engine's
conventional air-to-fluid radiator heat exchanger. It is preferred
a temperature controlled valve (not shown) be used to control the
volume or flow rate of engine coolant delivered to heat exchanger
326 so that the engine 302 is not overcooled. Worked fluid pump 330
maybe located before or after preheater 326, but preferably before.
Although not shown in FIG. 3, it will be appreciated that valves,
controllable valves, instruments or transducers can be located
adjacent the worked fluid inlet or outlet of the primary heat
exchanger 306 to monitor or control the properties and
characteristics of heated worked fluid 322.
[0081] System 300 may be instrumented as desired, and as
illustrated in FIG. 3, several temperature transducers, T, may be
beneficial. For example, monitoring the temperature T1 of the
working fluid 301 prior to entry into tank 310 is useful especially
where the tank is vented 312 to atmosphere. Keeping the temperature
of the working fluid 301 below its atmospheric boiling point will
prevent loss of the working fluid to the atmosphere. It may be
desired to monitor the temperature T4 of the working fluid 301 as
it enters the rotary heater 304 (or prior to charge air heat
exchanger 332) and/or prior to its entry T3 into the primary heat
exchanger 306. It will be appreciated that working fluid
temperature T3 can be controlled in several ways, including
adjusting the flow rate of the worked fluid through heat exchanger
306, and/or adjusting the torque generated by the rotary generator
302, and/or adjusting the flow of working fluid into the rotary
heating device 304. Controllable bypass loops (not shown) can also
be established for each heating source, such as rotary heater 304
and heat exchanger 316. It will be appreciated that the system 300
can be used to heat a fluid 322, i.e., the "worked fluid" by
passing the worked fluid through fluid-to-fluid heat exchanger 306.
A flow control device 330, such as a valve or a pump, can be used
to control the temperature, T2, of the worked fluid.
[0082] In FIG. 4, another embodiment of a flameless fluid heating
system 400 is illustrated. The fluid heating system 400 may
comprise a closed-loop heat transfer subsystem shown by a dashed
line 403. The closed-loop heat transfer system 403 of FIG. 4
comprises a diesel engine 402, which is preferably a 600
horsepower, Tier III, turbocharged, diesel engine; a rotary heating
device 404, which is preferably a Model TD3100 available from
Taylor Dynamometer; a working fluid tank 410; an engine exhaust gas
heat exchanger 416; and a primary fluid-to-fluid heat exchanger
406, all plumbed in closed-loop fluid communication.
[0083] The water brake 404 is directly coupled to the flywheel or
output shaft of the diesel engine 402. The inlet of the water brake
404 is coupled to a controllable valve 418 to control the amount of
closed-loop fluid, i.e., working fluid 401, allowed into the water
brake 404 at any given time. The water brake 404 heats the working
fluid 401 therein and discharges the heated working fluid to the
tank 410. For the embodiment of FIG. 4, the tank 410 is
un-pressurized and vented 412 to atmosphere, thereby operating at
atmospheric conditions.
[0084] Working fluid 401, which is preferably a glycol and water
mixture, is drawn from the tank 410 by pump 408 and the working
fluid that is that is not passed through valve 418 to the water
brake 404 is directed to exhaust gas heat exchanger 416 where it is
further heated by the engine exhaust gas 417. Heated working fluid
401 is then pumped from the exhaust gas heat exchanger 416 into the
primary heat exchanger 406, which is preferably a frame-and-plate,
fluid-to-fluid heat exchanger.
[0085] Also shown in FIG. 4 is an optional electrical generator 424
coupled to the engine 402. In the embodiment illustrated in FIG. 4,
the generator 424 is a 50 kilowatt AC generator producing 480 volt,
3 phase power for use in powering and controlling the various pumps
and instruments associated with system 400. FIG. 4 also shows
conventional engine radiator 434.
[0086] Having now described the heat transfer system 403
illustrated in FIG. 4, it will be appreciated that the system 403
may be run continuously to provide thermal energy in the working
fluid 403 that can be used to heat another fluid passing through
the other portion of primary heat exchanger 406.
[0087] To accomplish this heating of a another fluid, i.e., the
worked fluid 422, system 400 also comprises an open system 436
comprising an inlet pump 430 and an engine jacket heat exchanger
426 fluidly coupled to the primary heat exchanger 406. The
discharge side of the primary heat exchanger 406 comprises
instrumentation 438, such as but not limited to, temperature
transducers, flow rate transducers, mass flow rate transducers and
others; controllable valves 440, manual valves 442 and discharge
pumps 444, as desired or required for a particular purpose.
[0088] Because the diesel engine 402 preferred for use in this
embodiment described in FIG. 4 is air supercharged, the embodiment
of FIG. 4 includes a charge air heat exchanger 432 positioned
upstream of the engine jacket coolant heat exchanger 426. In this
configuration, the relatively cool fluid-to-be-heated 422 cools the
charge air before it is introduced into the engine's combustion
chambers, thereby preheating the worked fluid 422. Alternately, as
described with respect to FIG. 3, the charge air heat exchanger 432
may be located in the heat transfer system 403 and preferably
between the discharge of the primary heat exchanger 406 and the
tank 410.
[0089] It will now be appreciated that heating system 400 may be
used to heat fluids, i.e., a worked fluid 422, of all types by
flowing such fluid 422 through primary heat exchanger 406 as
illustrated in FIG. 4. System 400 may be instrumented as desired,
and as illustrated in FIG. 4, several temperature transducers, T,
may be beneficial. For example, monitoring the temperature T1 of
the worked fluid 422 prior to entry into charge air heat exchanger
432 and temperature, T2, of the worked fluid 422 exiting the system
400. It will be appreciated that worked fluid temperature T2 can be
controlled in several ways, including adjusting the flow rate of
the worked fluid through heat exchanger 406, and/or adjusting the
torque generated by the engine 402, and/or adjusting the flow of
working fluid into the water brake 404.
[0090] FIG. 5 illustrates another embodiment of a fluid heating
system 500 using aspects of my inventions. The system 500 comprises
a plurality of closed-loop heating circuits arranged sequentially
to heat a worked fluid 502. The fluid to be heated 502 is pumped
into the system 500 by a variable speed pump 504, such as those
offered by Viking. The speed control allows the residence time of
the fluid 502 within the system 500 to be controlled, thereby
controlling the final temperature, T4, of the fluid 502. Indeed, in
a preferred embodiment, temperature transducer T4 controls the pump
504.
[0091] The fluid 502 is pumped through one side/portion of a
fluid-to-fluid heat exchanger 506. In FIG. 5, heat exchanger 506 is
configured to transfer heat from an internal combustion engine's
(not shown) water jacket (working fluid #1) to the fluid 502. As
shown, this first closed-loop heating circuit may also include an
auxiliary air-to-fluid heat exchanger 508 (or radiator) to ensure
that the engine has adequate cooling, and may include an after
cooler heat exchanger 510 to cool supercharged or pressurized
intake air for the engine.
[0092] Fluid 502 heated by this first closed-loop section to
temperature T2 is pumped to a second fluid-to-fluid heat exchanger
512. Heat exchanger 512 is configured to transfer heat from another
fluid (working fluid #2) heated by a rotary heating device 514,
such as a water brake, to the fluid 502. The water brake 514,
preferably a TD3100 Taylor dynamometer, is driven by an internal
combustion engine (not shown), such as a 700 hp diesel engine. The
working fluid heated by the water brake is pumped 516 to an
atmospheric reservoir or accumulator 518. Controllable valve 520
controls the volume of working fluid entering the water brake 514
and, therefore, the temperature T6. After passing through heat
exchanger 512, the worked fluid 502 is heated to temperature
T3.
[0093] Fluid 502 heated by the first and second closed-loop
sections to temperature T3 is pumped to a third fluid-to-fluid heat
exchanger 522. Heat exchanger 522 is configured to transfer heat
from yet another fluid (working fluid #3) heated by an engine
exhaust heat exchanger 524, such as a finned tube air-to-fluid heat
exchanger, to the fluid 502. It will be appreciated that the
exhaust gasses from any internal combustion or external combustion
engine may be used by heat exchanger 524 to heat the working fluid.
In FIG. 5, exhaust gasses from the engine that drives rotary
heating device 514 and exhaust gasses from a 75 kW electrical
generator, which provides electricity for operating an controlling
the pumps, valves and other equipment associated with system 500,
are used to heat the working fluid.
[0094] The working fluid heated by the exhaust heat exchanger 524
is pumped 526 to the third fluid-to-fluid heat exchanger 522 to
raise the temperature of the worked fluid 502 to its final
temperature, T4. Working fluid exits the heat exchanger 522 and
flows into an atmospheric reservoir or accumulator 528.
Controllable valve 530 controls the residence time of the working
fluid in the heat exchanger 522 and, therefore, the temperature
T7.
[0095] While the system 500 illustrated in FIG. 5 is a sequential
or serial heating system, it will be appreciated that the plurality
of closed-loop heating circuits can be arranged in parallel similar
to the opened-loop system disclosed in FIG. 1.
[0096] It is contemplated that an embodiment of the system 500
illustrated in FIG. 5 may consume 5,000,000 Btu/Hr (35 gallons
diesel/hr) and transfer approximately 4,500,000 Btu/hr to the
worked fluid 502. The system 500 may raise the temperature of 60 F
water to 140 F at a rate of 2.7 Bbl/min or 3.1 hours for 500 Bbl,
and the temperature of oil at 60 F to 210 F at 3.3 Bbl/min.
[0097] Turning now to FIG. 6A, a direct-fired fluid heating system
600 is disclosed. The heating system 600 comprises a direct-fired
fluid heater 602, which is preferably a 5,000,000 BTU/hr natural
gas water heater, such as, for example, a Parker Boiler Model 6200.
It is contemplated that the heater 602 would be fired with waste
gas from the field metered into the heater 602 through pressure
control valve 604. Therefore, it is desirable that the heater 602
burner controls (not shown) allow for substantially real-time
gas-to-air adjustments to account for changing gas quality. The
working fluid in the closed-loop heating circuit is preferably a
50/50 mixture of water and glycol. The heater 602 heats the working
fluid to temperature T1, which may be, for example, 210 F. The
heated working fluid is pumped 606 through a fluid-to-fluid heat
exchanger 608 to transfer heat from the working fluid to the worked
fluid 610. Working fluid exits the heat exchanger 608 and enters an
atmospheric reservoir or accumulator 612. Pump 606 draws working
fluid out of the reservoir 612 and feeds it back to heater 602. A
temperature transducer T1 cooperates with controllable valve 604 to
control the temperature of the working fluid. In the system
illustrated in FIG. 6, the worked fluid may be heated to about 170
F.
[0098] FIG. 6B illustrates an alternative heating system 600
utlilizing a Diesel genset, 603 to power an electric boiler 604.
The heating system 600 comprises a Diesel engine 602 and electrical
generator 624, which together may be considered "genset" 603 and an
electrical boiler 604. The genset 603 generates electricity, such
as three-phase alternating current power, which is fed to the
electric boiler 604 by suitable power cables 625. The working fluid
in the closed-loop heating system is preferably a 50/50 mixture of
water and glycol. The boiler 604 heats the working fluid to
temperature T1, which may be, for example, 210.degree. F. The
heated working fluid is pumped 608 through a fluid-to-fluid heat
exchanger 618 to transfer heat from the working fluid to the worked
fluid 622. Working fluid exits the heat exchanger 618 and returns
to boiler 604. An reservoir or accumulator 610 may be utilized as
needed, and may be located before or after the boiler 604. FIG. 6B
shows an atmospheric reservoir 610 located downstream of boiler
604. A temperature transducer T1 cooperates with controllable
valves to control the temperature of the working fluid. In the
system illustrated in FIG. 6B, the worked fluid may be heated to
about 170 F.
[0099] Also shown in system 600 of FIG. 6B is an exhaust gas heat
exchanger 616 configured to transfer waste heat from the engine's
602 exhaust to the working fluid. As illustrated in FIG., 6B, the
exhaust gas heat exchanger 616 may be located downstream of the
boiler 604 and upstream of the primary heat exchanger 618. It will
be appreciated that other sources of waste heat may be captured to
heat the working fluid. For example as is taught herein with
respect to other embodiments of my inventions, a water jacket heat
exchanger (not shown) configured to use the waste heat from the
engine's 602 water jacket may be used to, for example, preheat the
worked fluid 622, or heat the working fluid. It will be appreciated
that a water jacket heat exchanger may be in addition to or in lieu
of the engine's conventional air-to-fluid radiator heat exchanger.
It is preferred a temperature controlled valve (not shown) be used
to control the volume or flow rate of engine coolant delivered to
the water jacket heat exchanger so that the engine 602 is not
overcooled. Also, as is taught herein with respect to other
embodiments of my inventions, waste heat from the engine's 602
mechanical or gas supercharger, if any, may be captured.
[0100] It will now be appreciated that FIGS. 1-6B illustrate merely
several of many possible embodiments of fluid heating systems (or
subsystems) using rotary heating devices, direct-fired heating
devices, or electric heating devices. Those of skill in the art
will be able to design closed- or opened-loop fluid heating systems
according to this disclosure for a wide variety of fluids and for a
wide variety of purposes, as contemplated by this disclosure. For
example, heating of corrosive or abrasive fluids may benefit from
the closed-loop design of FIGS. 2-6B, although the rotary heater,
direct-fired heater or electric heater may be fabricated from
corrosion and/or abrasion resistant materials, if desired, for
opened-loop systems. In addition, the temperature(s) to which the
fluid is heated may determine whether a closed- or open-loop system
is desired. For example, the potential for and effects of scaling
in the heat exchangers and/or heating devices should be considered
in any design incorporating the present inventions.
[0101] A fluid heating system, such as those described above, may
form a subsystem of a larger system, such as a fluid concentrating
system, a fluid evaporating system, a fluid separating system,
and/or a fluid pasteurizing system, as discussed below. Any person
of skill having benefit of this disclosure will know how to
interchange the various subsystems disclosed herein to achieve a
desired design goal. In addition, the fluid heating systems
described herein may be also used simply to heat fluids, such as,
without limitation, for paraffin flushing or for an oil well "kill"
truck.
[0102] Turning now to fluid evaporation systems and methods, such
systems may comprise a flash tank in which the heated worked fluid
is separated into vapor (e.g., steam) and liquid portions. The
steam portion may be passed through an air-to-fluid heat exchanger
to transfer heat from the steam to the air. The heated air may then
be used to evaporate some or the entire liquid portion of the
worked fluid.
[0103] FIG. 7 depicts one of many possible embodiments of a fluid
evaporating system 700. The system 700 may be characterized as
comprising a heating section 702 and an evaporating section 704. In
this embodiment, the heating section 704 comprises a rotary heating
device 710, preferably a cavitation-based rotary heater, such as
described previously, coupled to an output of a prime mover 712,
such as a diesel or most preferably a natural gas engine. Flex
joints or other coupling mechanisms (not shown) may be used as
needed to couple the engine 712 to the rotary heating device 710.
As will be described in more detail below, it is preferred that the
engine 712 cooling system, such as closed loop water jacket and
radiator 714, be a component of the heating section 702.
[0104] The fluid to be evaporated 716 (i.e., the worked fluid),
such as produced water, is introduced to a tank 718 by any
convenient means. It is preferred that the tank 718 have a level
control device 717 to control the amount of fluid 716 supplied to
the tank 718. The liquid phase of the fluid 716 is pumped by a
circulation pump 720 to the rotary heating device 710. It will be
appreciated that the pump system 120 may include one or more
filters, filtration system or other discrimination devices adapted
to remove particulate matter from the fluid 716. The type and
efficiency of the filtration system may be selected based on the
operational requirements of the rotary heating device 710 or other
heating system 702 component. In other words, particulate matter
may be removed as required to prevent damage to heating system 702
components. As the fluid 716 is pumped through the rotary heating
device 710, the device 710 heats the fluid 716, such through as
cavitation. Heated fluid 722 is returned to the tank 718 The return
conduit preferable includes a valve, orifice plate or other type of
restriction device 724 to create sufficient backpressure in the
heating section 702 to maintain sensible heat in the fluid 722.
[0105] As heated fluid 722 enters the tank 718 it may flash, with a
portion of the fluid 722 becoming steam and with the remainder
being liquid. The steam portion 726 of the fluid 722 is
communicated to a heat exchanger 728, which is preferably a finned
tube air-to-fluid condenser adapted to remove heat from the fluid
726. It is preferred that a demister 727 be used to ensure that the
fluid 726 is clean vapor. As the fluid 726 condenses, it collects
and can be extracted from the heat exchanger 728 by known means as
condensate 730.
[0106] As shown in FIG. 7, ambient air 732 is forced through engine
heat exchanger or radiator 714 to maintain the engine 712 at
operating temperature. Heated air 734 may be passed through the
condenser 728 to further heat the air by transferring heat from the
fluid 726 as described previously. The primary end product of
heating system 702 is heated air 736.
[0107] Evaporation section 704 may comprise one or more evaporation
chambers 750. As illustrated in FIG. 7, evaporation section 704
comprises a first evaporation chamber 752. In this chamber, a
selected portion of the liquid phase 754 of fluid 722 is injected,
such as by spraying, into the chamber 752. It is preferred that the
chamber 750 be oriented such that fluid 754 is sprayed or injected
adjacent the top of the chamber 750 so that the fluid falls through
the heated air 736. A restriction device 755, such as a valve
and/or orifice plate, may be used to control the volume of liquid
fluid 754 introduced into the chamber 750. It is preferred that the
restriction device 755 be a variable flow rate control valve
adapted to receive control information form a liquid level
indicator in the chamber 750, as discussed below. A fluid 716
preheater (not shown), such as a fluid-to-fluid heat exchanger, may
be used to preheat the fluid 716 with fluid heater fluid 754.
[0108] Heated air 736 is forced into and through the chamber to
contact the liquid fluid 754. The heated air 736 causes a portion
of the liquid 754 to evaporate and exit the chamber 752 as heated
moist air 756. That portion of the fluid 154 that does not
evaporate collects in the bottom of the chamber 752. Because this
collected fluid likely has some degree of particulate
contamination, it is desirable to agitate or stir the fluid, such
as by fluid circulation. In a preferred embodiment, a circulation
pump and filter system 758 is used to both agitate the fluid that
collects in chamber 752 and to filter out the particulate
contaminate 760, which can be disposed of as required and
allowed.
[0109] Also shown in FIG. 7 is a second evaporation chamber 762.
Chamber 762 may use fluid collected in chamber 752 as shown by
transfer conduit 764. Additional evaporative heat may be supplied
to chamber 762 by exhaust 766 from engine 712. Thus, chamber 762
uses moist heated air 756 and exhaust gases 766 to evaporate
another portion of fluid 754. The evaporated fluid is released from
the chamber 762 as heated, moist air 770. Chamber 762 may also
include a circulation pump and filter system 772 to both agitate
the fluid that collects in chamber 762 and to filter out the
particulate contaminate 774, which can be disposed of as required
and allowed. The pump system 772 may also be used to re-inject (or
re-spray) the fluid 754 in subsequent chambers.
[0110] As discussed above, evaporation section 704 comprises a
fluid level control, preferably associated with chamber 762, so
that the system 700 is controlled to allow most of the fluid 754
entering evaporation section 704 to be evaporated. Chamber 762 also
includes a reduced water blow down valve 776 that allows extraction
and disposal of concentrated or reduced water, such as that portion
of fluid 754 this is not evaporated.
[0111] Having now described an embodiment of a fluid evaporation
system 700, it will be apparent that the invention has multiple
synergistic attributes and functionalities. For example, using the
engine 712 exhaust gases 766 to evaporate a portion of the fluid
722 also cleanses to a certain degree the exhaust gases that are
returned to the environment. In addition, it should be noted that
the fluid 754 to be evaporated is the working fluid as well.
[0112] A specific construction of the produced water evaporator
system described above was designed to use a 36-inch diameter Shock
Waver Power Reactor fabricated under license from Hydro Dynamics,
Inc. The SPR was coupled to a 600 horsepower natural gas engine
having a fuel consumption of 4,300 cubic feet per hour. The system
was designed to accept up to 7,250 pounds of produced water per
hour (approximately 14.5 gallons per minute). The system 100 was
designed to evaporate approximately 80% of the produced water input
or 5,800 pounds/hour, and to create approximately 1,450 pounds/hour
of reduced (unevaporated) water for disposal. The system 100 was
also calculated to produce about 1,500 pounds/hour (approximately
3.0 gallons per minute) of condensate or distilled water. The
finned tube condenser was designed to have aluminum fins on carbon
steel tubes having about 6,800 square feet of surface area and
adapted to exchange about 3,337,565 BTU/hour. The heating section
was designed to operate at about 250.degree. F. at about 35 psig.
An orifice or other restriction, such as valve 724, adjacent the
flash tank is useful to maintain these operating conditions. The
flash tank was designed to operate at about 220.degree. F. at about
10 psig. The condenser was designed to output air heated to about
200.degree. F. at a velocity of about 10 feet per second.
[0113] The evaporator chambers were designed as a fiberglass tank
having four successive sections. In the first evaporative section,
it was contemplated that liquid from the flash tank would be
sprayed into the chamber at about 150.degree. F. TO 220.degree. F.
(depending, for example, on whether a fluid 716 preheater is used)
in the presence of about 200.degree. F. air. Two successive
chambers were designed to spray unevaporated liquid from the prior
sections across the heated air flowing through the chambers. The
third section was similarly designed. The last section utilized the
heat energy from the engine exhaust gases to aid further
evaporation of the fluid. After passing through the four chambers,
the heated air, laden with moisture from the fluid, was expelled
from the system. As described above, reduced, unevaporated water,
which is likely laden with particulates, such as salts of sodium,
magnesium and/or calcium, chlorides, sulfates and/or carbonates,
may be expelled from the evaporation chamber 750.
[0114] It will be appreciated that whether to use the heat energy
from the engine exhaust and whether to use one or multiple
evaporation chambers or process sections is a matter of design
choice based upon numerous design criteria well within the
capabilities of those of skill in this art having benefit of this
disclosure.
[0115] FIG. 8 illustrates an embodiment of a fluid evaporating
subsystem 804. It will be appreciated that FIG. 8 is based on the
embodiment shown in FIG. 7. In fact, the reference numbers used in
FIG. 7 directly translate to those used in FIG. 8. For example,
reference number 814 identifies structure similar to that shown as
714 in FIG. 7.
[0116] The modifications disclosed in FIG. 8 involve using two
separate evaporation chambers 852, 862. Chamber 852 is a "clean"
evaporation chamber in that the evaporating air 836 is air heated
by the condenser 828. Rather than the optional filtration system
758 described in FIG. 7, FIG. 8 makes use of particle separating
system 859, which may comprise a particulate separator, such as a
hydrocyclone separator, and a settling bin. The particulate matter
860 that is recovered from system 859 is "clean" in that it will
have little to no atmospheric contamination and, to the extend a
market exists, the particulates recovered may be reused or
sold.
[0117] The second evaporation chamber 862 is a "dirty" chamber in
that engine exhaust gases 866 are used in conjunction with air 834
heated by engine radiator 814 to evaporate fluid 864. It is
believed that the modifications disclosed in FIG. 8 results in a
better heat balance than the embodiment disclosed in FIG. 7. Also
shown in FIG. 8, the "dirty" chamber 862 may use a particle
separating system 873 as described above.
[0118] Illustrated in FIG. 9 is an embodiment of an evaporation
system 900 particularly suited for evaporating water produced from
subterranean wells or mines. Shown generally by dashed line is a
heating subsystem 902 (as described below, flash tank 904 is
rightly considered a part of the evaporation subsystem 906 and not
the heating subsystem 902, and engine jacket heat exchanger 907 is
rightly a part of the heating subsystem 902).
[0119] Closed-loop heating subsystem 902 comprises a rotary
generator 908, preferably a natural gas or diesel engine, coupled
to a rotary heating device 910, preferably a water brake
dynamometer. The rotary heater 910 is plumbed in closed-loop
fashion to a tank 912 that is vented to the atmosphere, a
circulation pump 914, such as a centrifugal pump, an engine exhaust
gas 960 heat exchanger 916, engine jacket heat exchanger 907 and a
primary heat exchanger 918. It will be appreciated that the heating
subsystem 902 may comprise any of the heating subsystems described
with reference to FIGS. 1-8.
[0120] Also shown in FIG. 9 is rotary heater bypass 920 and bypass
valve 921. In a preferred embodiment, the temperature T3 of the
working fluid as it enters the primary heat exchanger 918 is used
to control the position of the bypass valve 921 to maintain the
temperature of the working fluid at a desired point, such as at a
temperature below its atmospheric boiling point.
[0121] Also illustrated in FIG. 9 is an evaporating section 906
comprising a inlet 930 for the worked fluid (i.e., the fluid that
is subject to evaporation), a positive displacement feed pump 932,
preferably a Moyno metering pump, and a fluid-to-fluid heat
exchanger 934 adapted to preheat the worked fluid with heat from
the engine jacket coolant. Preheated worked fluid is pumped 935 to
the primary heat exchanger 918 where it picks up additional energy
from the heating subsystem 902. The heated worked fluid is pumped
to the flash tank 904 through orifice or valve 936, which is
selected to maintain sufficient pressure in the system to prevent
the fluid from flashing (i.e., vaporizing) until it enters the
flash tank 904. It is preferred that the flash tank operate at
negative atmospheric pressure, typically around about 0.9 to 2.5
psia (i.e., a vacuum of about 25 to 28 inches of mercury). A vacuum
system 938, such as a liquid ring pump, may be used to maintain the
vacuum in the flash tank. It will be appreciated that as heated
fluid enters the flash tank 904 a portion flashes off into steam
(or vapor), which is drawn by vacuum system 938 to an air-to-fluid
heat exchanger 940, preferably a finned tube heat exchanger.
Ambient air 942a is forced through heat exchanger 940 to transfer
heat from the fluid vapor to the air 942a. As will be described
below, the heated air 942b will be used to evaporate fluid that
collects in the flash tank 904.
[0122] The transfer of heat in heat exchanger 940 causes the fluid
vapor to condense to liquid, which is collected in a condensate
receiver 944. It is preferred that the condensate receiver 944 be
equipped with a fluid level control adapted to control a condensate
pump 946. The level control and pump 946 may be configured to
maintain a relatively fixed fluid level in condensate receiver 944.
It will be appreciated that condensed fluid 948, for example water,
may be used for various purposes as needed (e.g., for
desuperheating purposes) or disposed of as allowed.
[0123] Returning to the heat exchanger 940, heated air 942b exits
the heat exchanger 940 and a portion is forced through the engine
jacket heat exchanger or radiator 907, where the air 942b picks up
additional heat. This heated air 942c along with the remainder of
the air 942b is forced through one or more evaporation chambers
950. Evaporation chamber 950 may be considered a "clean" chamber
insofar as the heated air 942c is relatively clean, typically
having only natural contaminants, such as dust, pollen and the
like.
[0124] A fluid pump 952, such as a variable positive displacement
pump, is coupled to the flash tank 904 so that collected fluid,
i.e. liquid, is pumped to evaporation chamber 950. It is preferred
that spray nozzles or other types of misting or spraying devices be
used to spray or mist flash tank 904 fluid inside chamber 950. In a
preferred embodiment, one or more spray nozzles are located
adjacent an upper surface of the chamber 950. Also in the preferred
embodiment, heated air 942c is forced to flow substantially normal
or perpendicular to the sprayed fluid to thereby evaporate at least
a portion of the liquid. It will be appreciated that suitable
baffles or other contact surfaces can be installed in chamber 950
to minimize or eliminate condensed fluid from exiting chamber 950
with heated moist air 942d.
[0125] Unevaporated fluid collects in the chamber 950 and a
circulation pump 954 may be used to recirculate this fluid through
the chamber for additional evaporation. Additionally, if desired,
the fluid can be passed through a filtration or separation system
956 to remove particulates 957 from the fluid. It is preferred that
separation system 956 comprises a hydrocyclone. Excess fluid from
system 956 can be returned to the chamber 950 for evaporation.
Recovered particulates 957 can be disposed of as allowed, or if a
market exists for such recovered particulates, for example, for
gypsum, sold.
[0126] If only one evaporation chamber 950 is utilized, it is
preferred that chamber 950 comprise a fluid level control device
adapted to control fluid pump 952, preferably a positive
displacement pumps such as those offered by Moyno, to maintain the
fluid flow and evaporation through chamber 950 at a desired
level.
[0127] Optionally, an additional evaporation chamber 958 may be
utilized as desired. This evaporation chamber 958 may be described
as a "dirty" chamber in that exhaust gasses from rotary generator
908 (e.g., natural gas or diesel engine) may be used to further
evaporate fluid.
[0128] Exhaust gasses 960 from the heat exchanger 916 are
introduced, along with warm, moist air 942d, if desired, into
chamber 958. Chamber 958 may be designed similarly to chamber or
chamber 950. Fluid to be evaporated may be drawn from chamber 950
and sprayed or otherwise contacted with air 942d and gasses 960 to
evaporate at least a portion of the fluid. Chamber 958 may likewise
comprise a circulation pump 962 and filter/separation system 964,
as desired. It will be appreciated that an additional benefit of
"dirty" chamber 958 is that it can be used to scrub or clean the
exhaust gasses 960 prior to discharge into the environment.
[0129] It will be appreciated that system 900 can be designed and
operated to evaporate all of the fluid input into the system or
only a portion of the fluid inputted. For those systems where less
than complete evaporation is desired or required, evaporation
chamber blowdown may be extracted and disposed of as allowed and
required. For systems utilizing scrubbing of the exhaust gasses,
disposal of at least a portion of the blowdown will likely be
required.
[0130] FIGS. 10 and 11 illustrate alternate embodiments of fluid
evaporating systems and methods. The detailed description set forth
above with respect to FIG. 9 substantially applies to FIGS. 10 and
11 with common structures having similar reference numbers. For
example, in all of FIGS. 9, 10 and 11, the flash tank is identified
by reference number 904, 1004 and 1104, respectively.
[0131] Concerning FIG. 10, incoming fluid 1030 is mixed with fluid
from the flash tank 1004 and then split with a portion flowing
directly to primary heat exchanger 1018 and back to the flash tank
1004, and the other portion diverted to the evaporation chamber
1050 for evaporation. In one embodiment, as the amount of total
dissolved solids, TDS, in the flash tank increases, more fluid is
diverted to the evaporation chamber 1050, which allows more new
fluid 1030 to enter the system. For example, a TDS instrument 1033
may be used to control flow device 1037 based on the TDS value
determined.
[0132] Additionally, FIG. 11 discloses the flash tank having a
demister hood 1139 to ensure that the vapor conducted to the heat
exchanger 1140 is relatively dry. In addition, chamber 1150 is
disclosed as having an agitator system 1151 to keep any particulate
matter suspended in the liquid fluid for removal by systems 1156
and 1157. FIG. 11 also shows a desuperheating inlet 1141 allowing
the introduction of fluid, if needed, such as condensate, to
desuperheat the steam entering the condenser 1140.
[0133] In the embodiment shown in FIG. 11, inlet pump 1132 may be
controlled by a fluid level control associated with flash tank
1104, and evaporator pump 1152 may be controlled by the TDS of the
fluid in the flash tank 104 and/or a fluid level control in the
evaporator reservoir 1150. The embodiment shown in FIG. 11 may be
operated to achieve substantially complete evaporation of the
inputted fluid.
[0134] An embodiment of an evaporator system utilizing aspects of
the present inventions was designed for produced water having total
dissolved solids of about 9,000 parts per million. A 600 horsepower
natural gas engine with a fuel consumption of 4,300 cubic feet per
hour was selected as the prime mover. The system was designed to
accept up to 7,135 pounds of produced water per hour (approximately
14.3 gallons per minute). The system was designed to evaporate
approximately 100% of the produced water input or 7,135
pounds/hour, and to create approximately 2,651 pounds/hour
condensate for use or disposal. The system was calculated to
produce about 1,500 pounds/day of solids for disposal. The finned
tube condenser was designed to have aluminum fins on carbon steel
tubes having about 6,800 square feet of surface area and adapted to
exchange about 3,337,565 BTU/hour. The heating section was designed
to operate at between about 150 and 180.degree. F. at about
atmospheric pressure. The flash tank was designed to operate at
about 130 to 170.degree. F. at about 25 inches of mercury (vacuum).
The condenser was designed to output air heated to about
130.degree. F. at a velocity of about 60,000 cfm.
[0135] As will now be appreciated, FIGS. 9, 10 and 11 illustrate
merely three of many embodiments of a fluid evaporator comprised of
a flameless heating subsystem and an evaporation subsystem.
Depending upon the characteristics of the fluid to be evaporated
(the worked fluid), the environment in which the system will be
used and economic considerations, the evaporation system may be
designed and operated to evaporate substantially all of the worked
(e.g., produced water) or only a portion of the worked fluid, with
the remainder being disposed of, if necessary, by allowable and
economic means.
[0136] It will also be appreciated that any of the embodiments
illustrated and described in FIGS. 7-11 may be implemented with any
of the various heating subsystems described herein, including, but
not limited to, a rotary heating subsystem, a direct fired or open
flame heating system or an genset/electric boiler subsystem.
[0137] FIG. 12A illustrates a fluid evaporating system and method
comprising a direct-fired heating subsystem coupled to a single
chamber evaporation subsystem. For all intents and purposes, the
systems illustrated in FIGS. 11 and 12A are the same except that
the fluid heating subsection 1202 in FIG. 12A is direct fired.
Thus, the description and operation of the fluid evaporating
subsystem in FIG. 11 applies to the fluid evaporating subsystem of
FIG. 12, where like structures have like numbers. For example,
flash tank is 1104 in FIGS. 11 and 1204 in FIG. 12A.
[0138] Concerning the fluid heating system 1202, this subsystem is
similar to the fluid heating system illustrated and described in
FIG. 6. The heating system 1200 comprises a direct-fired fluid
heater 1204, which is preferably a 5,000,000 BTU/hr natural gas
water heater, such as a Parker Boiler Model 6200. It is
contemplated that the heater 1204 would be fired with waste gas
from the field metered into the heater 1204 through pressure
control valve 1206. Therefore, it is desirable that the heater 1204
burner controls (not shown) allow for substantially real-time
gas-to-air adjustments to account for changing gas quality. The
working fluid in the closed-loop heating circuit is preferably a
50/50 mixture of water and glycol. The heater 1204 heats the
working fluid to temperature T1, which may be, for example,
210.degree. F. The heated working fluid is pumped 1208 through a
fluid-to-fluid heat exchanger 1210 to transfer heat from the
working fluid to the worked fluid. Working fluid exits the heat
exchanger 1210 and enters an atmospheric reservoir or accumulator
1214. Pump 1208 draws working fluid out of the reservoir 1214 and
feeds it back to heater 1204. A temperature transducer T1
cooperates with controllable valve 1206 to control the temperature
of the working fluid. In the system illustrated in FIG. 12A, the
worked fluid may be heated to about 170.degree. F.
[0139] FIGS. 12B and 12C illustrate other fluid concentrating
systems 1200 in accordance with aspects of the present inventions
using multiple-effect evaporation. As is known, multiple-effect
evaporation is an evaporation process for efficiently using the
heat from steam to evaporate water. In a multiple-effect
evaporator, water is boiled in a sequence of vessels, each operated
at a successively lower pressure. Because the boiling temperature
of water decreases as pressure decreases, the vapor (i.e., steam)
boiled off in one vessel can be used to heat the next, and only the
first vessel, which operates at the highest pressure requires an
external source of heat. Evaporation systems with more than four
stages are rarely practical, although some multiple-effect systems
have up to seven stages.
[0140] As illustrated, the fluid evaporating system 1200 of FIG.
12B comprises a heating subsystem 1202, such as any of those
described above with respect to FIGS. 1-6. The particular fluid
heating subsystem 1202 illustrated in FIG. 12B is a closed-loop
subsystem similar to that illustrated in and described by FIGS. 6
and 12A. The reference numbers and descriptions used for FIG. 12A
are applicable to FIG. 12B as well. For example, direct-fired
heater 1204 in FIG. 12A is direct fired heater 1204 in FIG. 12B.
The heating subsystem show in FIG. 12B is preferably configured to
achieve a 750 gallon/minute flow rate.
[0141] The fluid evaporating system 1200 also comprises an
evaporating subsystem 1203. In subsystem 1203, pressurized and
metered fluid 1220 is circulated to primary heat exchanger 1210
where the fluid 1220 is heated by the working fluid from heating
subsystem 1202. Heated fluid 1220 is passed through an orifice or
valve 1226 adapted to create a pressure differential across the
device 1226. The fluid 1220 is flashed into tank 1228 where it is
separated into its vapor and liquid phases. The flash tank 128 is
preferably operated under negative atmospheric pressure of about
6.4 psia (i.e., a vacuum of about 17 inches of mercury). A vacuum
system 1230, such as a liquid ring pump, may be used to maintain
the system vacuum.
[0142] The vapor phase of fluid 1220, such as steam at about
172.degree. F., is passed through a heat exchanger 1270, which may
be a fluid-to-fluid heat exchanger. Heat exchanger 1270 functions
to transfer heat from the first evaporation stage to the second
evaporation stage. In the second stage, pressurized and metered
fluid 1220 is circulated to heat exchanger 1270 where the fluid
1220 is heated by the steam from the first evaporation stage.
Heated fluid 1220 is passed through an orifice or valve 1272
adapted to create a pressure differential across the device 1272.
The fluid 1220 is flashed into tank 1274 where it is separated into
its vapor and liquid phases. The flash tank 1274 is operated under
atmospheric pressure less than the operating pressure of tank 1228
(first stage tank), e.g., at about 3.2 psia (i.e., a vacuum of
about 23.5 inches of mercury). A vacuum system 1276, such as a
liquid ring pump, may be used to maintain the system vacuum.
[0143] The vapor phase of fluid 1220, such as steam at about
135.degree. F., may be passed through a heat exchanger 1278, which
may be an air-to-fluid heat exchanger. The steam, or a portion
thereof, is condensed by heat exchanger 1278 and passed to a
condensate receiver 1234, which, preferably is operated under
vacuum to remove any volatile components. Any such volatiles may be
feed as fuel to the heating subsystem 1202. A condensate pump may
be used to remove the condensate, e.g., distilled water, from the
condensate receiver. Similarly, the steam entering heat exchanger
1270 is condensed and may be collected in receiver 1234.
[0144] Referring back to flash tanks 1228 and 1274, concentrated
liquid accumulates in each tank and may be circulated by pumps
1224. A metering and detecting system may be used to assess,
determine or calculate one or more properties of the concentrated
fluid. For example, a system can be implemented to determine the
temperature, density, specific gravity, conductivity, flow rate or
other property or characteristic of the concentrated fluid. An
extraction system 1241, such as a variable speed pump may be
adapted to extract the desired concentrated fluid from the system
1200 when it has the desired properties. A metering device may be
used to determine the amount of concentrated fluid removed from the
system.
[0145] Also, as illustrated in FIG. 12B, concentrated fluid from
tank 1228, at about 172.degree. F. is mixed with incoming fluid
1220 to raise the fluid temperature before it enters primary heat
exchanger 1218. Similarly, concentrated fluid from tank 1274, at
about 144.degree. F. is mixed with incoming fluid 1220 to raise the
fluid temperature before it enters heat exchanger 1270.
[0146] It will now be appreciated that the system illustrated in
FIG. 12B can be used to evaporate fluids, such as produced water or
flowback. For example, it is postulated that the system illustrate
in FIG. 12B can process about 875 barrels of produced water having
a total dissolved solids of 60,000 ppm into about 688 barrels of
distilled water and 210 barrels of 10 lb.sub.f Brine solution every
24 hours. The optional spray chamber 1290 illustrated in FIG. 12B
will dispose of another 250 barrels of produced water in a 24 hour
period.
[0147] Oftentimes, an amount of fluid to be evaporated or processed
will be stored in large volumes in an open pit, storage device,
tank, or other retention area. Usually such storage device will be
open to atmosphere, such that the fluid will exist at ambient
temperature and ambient pressure. It is preferred, but not
necessary, that solids be allowed to settle out and lighter
components, such as oil or other hydrocarbons, to be skimmed off
for use or sale. The fluid of interest can then be suctioned out of
the tank.
[0148] An additional stage of evaporation may be achieved by
replacing the air-to-fluid condensing heat exchanger, such as, but
not limited to, condenser 1278 in FIG. 12B, with a fluid-to-fluid
heat exchanger, such as, but not limited to, a plate and frame heat
exchanger and using the untreated fluid in the storage device for
cooling. FIG. 12C, for which reference to the description of FIG.
12B should be made, illustrates a system 1203 with a fluid-to-fulid
condensing heat exchanger 1279. After passing through the
fluid-to-fluid heat exchanger 1210, the heated untreated fluid may
be sprayed or passed over an inclined plate on its return to the
retention area. This addition would utilize the absorbed heat to
evaporate an additional portion of the fluid. Heat not removed by
the latent heat of evaporation would be recovered as preheated
incoming fluid to the evaporation or other fluid manipulating
system. Those of skill will appreciate that the cost of an
air-to-fluid heat exchanger typically will be higher than a
fluid-to-fluid heat exchanger for the modification discussed
here.
[0149] It will also be appreciated that the evaporator systems can
be used to remove (by evaporation) fluid from the worked fluid to
effectively concentrate the worked fluid. The concentrated fluid
can be extracted from one or more of the evaporation spray
chambers. It will also be appreciated that it may not be desirable
to concentrate certain worked fluids (e.g., a diluted well
completion fluid) by forcing heated ambient air through the fluid.
Particles entrained in the air, such as dirt, dust, pollen, or
exhaust gasses may contaminate the worked fluid.
[0150] It will be appreciated that the evaporator systems described
herein also produce a "blowdown" fluid, such as the liquid in the
flashtank(s).
[0151] Depending on the raw fluid from which water is evaporated,
the blowdown may be a desirable product. For example, when
evaporating produced water, the blow down likely will be a
concentrated brine solution, which have many oil field uses. As
shown in the various Figures provided with this disclosure and as
discussed herein, a measurement device or meter may be used to
determine one or more properties of the flash tank liquid phase, so
that the liquid phase, or a portion of the liquid phase, may be
withdrawn when the desired fluid properties are reached. For
example, meter 1280 is illustrated in FIGS. 12A,12B and 12C. A
measurement device that is presently preferred for all my
inventions disclosed herein is the ProMass line of flow meters
offered by Endres+Hauser.
[0152] Thus, my inventions can be adapted to create a fluid
concentrator subsystem comprising a flash tank in which the heated
worked fluid is separated into vapor (e.g., steam) and liquid
portions. The steam portion may be passed through an air-to-fluid
heat exchanger to condense the steam back to liquid. The condensed
liquid may be removed from the worked fluid thereby concentrating
the worked fluid.
[0153] Turning now to FIGS. 13A and 13B, embodiments of a fluid
concentrating subsystem 1300 are presented. These two embodiments
utilize primary heat exchangers 1304 that separate the working
fluid 1302 heating subsystem 1303 from the concentrating subsystem
1301. It will be appreciated that any of the foregoing heating
subsystems described with respect to FIGS. 1-12C may be used with
the fluid concentrating subsystems illustrated in FIGS. 13A and
13B. FIG. 13B illustrates a direct-fired heating subsystem
1303.
[0154] It also will be appreciated from this disclosure that an
opened-loop fluid concentrating system may be designed by, among
other things, eliminating the primary heat exchanger 1304. For
example, the opened-loop fluid evaporating system of FIG. 7 can be
modified according to the teaching of this disclosure to produce an
opened-loop fluid concentrating system.
[0155] Returning to FIGS. 13A and 13B, diluted fluid (aka the
"worked" fluid), such as a completion fluid recovered from a well,
1305 is introduced into the system 1300. A metering system 1306 may
be used to determine the amount of diluted fluid introduced. A
circulation pump 1308 is used to circulate the diluted fluid
through the primary heat exchanger 1304 to pick up heat from the
heating subsystem 1303. The heated, dilute fluid 1305 flows through
a valve or other flow restriction device 1310 configured to create
a pressure differential across the device 1310 of about 30 psid.
The fluid 1305 is flashed into tank 1312 where the fluid is
separated into its vapor and liquid phases.
[0156] The flash tank 1312 is preferably operated under negative
atmospheric pressure of about 0.9 to 2.5 psia (i.e., a vacuum of
about 25 to 28 inches of mercury). A vacuum system 1314, such as a
liquid ring pump, may be used to maintain the system vacuum. The
vapor phase of fluid 1305, such as steam, is passed through a heat
exchanger 1316, which may be a fluid-to-fluid or air-to-fluid heat
exchanger. Heat exchanger 1316 functions as a condenser to condense
the fluid vapor to its liquid phase, e.g., water. The condensed
fluid 1317 is collected in a reservoir 1318. Alternately, the
condensate can be used to preheat the incoming fluid 1305. It is
preferred that reservoir 1318 be equipped with a level control
system that controls a condensate pump 1320. It will be appreciated
that the condensate that is produced by system 1300 is relatively
clean and may be used for a variety of purposes or discarded as
allowed.
[0157] Referring back to flash tank 1312, concentrated liquid fluid
1342 accumulates in the tank and may be withdrawn by a fluid
extraction and metering system 1322, such as described below with
respect to FIGS. 15 and 16.
[0158] In addition to being coupled to opened-loop or closed loop
heating subsystems, such as those described above with reference to
FIGS. 1-6, the fluid concentrating subsystem embodiments described
in FIGS. 13A and 13B are particularly suited for use on offshore
drilling or production platforms. FIG. 14 illustrates a fluid
concentrating system adapted for an offshore rig, in which the
heating subsystem 1402 (not shown) comprises the stationary engines
of the rig. The description with respect to FIGS. 13A and 13B apply
to like structures in FIG. 14. In such application, an existing
thermal energy source from the rig or platform may be utilized. For
example, and preferably, the primary working fluid 1302, 1402 is
preferably a fluid heated by conventional rig equipment, such as
one or more internal combustion engines. For example, the working
fluid may comprise the liquid coolant from diesel engines (e.g.,
water jacket coolant).
[0159] FIGS. 15 and 16 illustrate fluid concentrating systems 1500
and 1600 in accordance with aspects of the present inventions. For
purpose of this description, like elements have like reference
numerals. Thus, for example, the condensate reservoir is referenced
as structures 1534 and 1634 in FIGS. 15 and 16, respectively. While
only reference numbers found in FIG. 15 may be described, this
description will be understood to apply equally to similarly
referenced elements in FIG. 16.
[0160] The fluid concentrating system 1500, 1600 comprises a
flameless heater subsystem 1501, 1601, such as those described
above with respect to FIGS. 1 - 6. The particular fluid heating
subsystem illustrated in FIGS. 15 and 16 is a closed-loop subsystem
similar to that illustrated in and described by FIG. 2. The
reference numbers and descriptions used for FIG. 2 are applicable
to FIGS. 15 and 16 as well. For example, rotary heating device 204
in FIG. 2 is rotary heating device 1504 in FIGS. 15 and 1604 in
FIG. 16.
[0161] The fluid concentrating system 1500, 1600 also comprises a
concentrating subsystem 1503, 1603. In subsystem 1503 and 1603,
fluid to be concentrated 1520 (aka, the "worked" fluid) is
preheated in heat exchanger 1522, which is adapted to transfer heat
from the condensed fluid, as will be described below, or from the
engine 1502 water jacket as described previously. Pressurized and
metered fluid 1520 is circulated to primary heat exchanger 1518
where the fluid 1520 is heated by the working fluid from heating
subsystem 1501. Heated fluid 1520 is passed through an orifice or
valve 1526 adapted to create a pressure differential across the
device 1526 of about 30 psid. The fluid 1520 is flashed into tank
1528 where it is separated into its vapor and liquid phases. The
flash tank 1528 is preferably operated under negative atmospheric
pressure of about 0.9 to 2.5 psia (i.e., a vacuum of about 25 to 28
inches of mercury). A vacuum system 1530, such as a liquid ring
pump, may be used to maintain the system vacuum.
[0162] The vapor phase of fluid 1520, such as steam, is passed
through a heat exchanger 1532, which may be a fluid-to-fluid or
air-to-fluid heat exchanger.
[0163] Heat exchanger 1532 functions as a condenser to condense the
worked fluid vapor to its liquid phase. The condensed worked fluid
is collected in a reservoir 1534 and, as mentioned above, may be
passed through preheater 1522 to preheat the fluid 1520 (and to
cool the condensate). As shown in FIGS. 15 and 16A, the preheater
1522, 1622 utilizes water jacket coolant from engine 1502, 1602. It
is preferred that reservoir 1534 be equipped with a level control
system that controls a condensate pump 1536. It will be appreciated
that the condensate that is produced by system 1500 is relatively
clean and may used for a variety of purposes or discarded as
allowed.
[0164] Referring back to flash tank 1528, concentrated liquid fluid
accumulates in the tank 1528 and may be circulated by pump 1524. A
metering and detecting system 1540 may be used to assess, determine
or calculate one or more properties of the concentrated fluid. As
previously mentioned, the Promass line of flow meters offered by
Endres+Hauser are suitable for this implementain. For example,
system 1540 can be adapted to determine the temperature, density,
specific gravity, conductivity, flow rate or other property or
characteristic of the concentrated fluid. An extraction system
1541, such as a variable speed pump controlled by system 1540 may
be adapted to extract the desired concentrated fluid from the
system 1500. A metering device may be used to determine the amount
of concentrated fluid removed from the system.
[0165] A valve or other flow-restricting device 1538 may control
the amount of incoming fluid 1520 allowed into the subsystem 1503,
which valve may be controlled by a fluid level device in flash tank
1528. In other words, additional fluid is allowed into subsystem
1503 to maintain a desired level of fluid in flash tank 1528. As
fluid is extracted from the subsystem 1503 through valve 1542, the
liquid level in tank 1528 decreases thereby allowing more fluid
1520 into the system. To the extent it is desired to cool extracted
concentrated fluid, such fluid may be used, for example, to preheat
incoming fluid 1520.
[0166] Also illustrated in FIGS. 15 and 16 is an optional
desuperheat inlet into heat exchanger 1532, 1632. In the event the
steam entering the heat exchanger is superheated, fluid, such as
liquid water, can be introduced through valve 1550, 1650 to
desuperheat the steam. Condensate removed from the system can be
used for this purpose.
[0167] FIG. 17 illustrates a fluid separating system 1700 according
to aspects of the invention previously described, such as in FIGS.
1-16, and like structures have similar reference numbers. For
example, in FIG. 16 the fluid heat exchanger is reference number
1618 and in FIG. 17 it is 1718. System 1700 incorporates a fluid
separation tower or fluid fractionating tower 1775 to separate the
heated fluid into some or all of its boiling point fractions. As is
well known in the art, fractionating columns separate a fluid
mixture by condensing vapor fluids in accordance with Raoult's law.
Each condensation-vaporization cycle causes fluid vapor of a
particular boiling point to be separated out. Fluid exiting the top
of the column 1775 is vapor and is passed to condenser 1732 to be
condensed back to a liquid. The condensed liquid 1780 may be
reinjected into the column 1775 through reflux lines 1782. It will
be appreciated that concentrated fluid 1784 exits system 1700 from
the bottom of the column or tower 1775.
[0168] FIG. 18 illustrates another fluid separating system 1800 in
which the engine 1802 drives an electrical generator 1860, such as
described with reference to FIG. 3, rather than rotary heater 1704.
The energy generated by generator 1860 is used, at least, to heat
the working fluid in an electrical heater 1862. In all other
material respects, the embodiments illustrated in FIGS. 17 and 18
are similar.
[0169] As with other systems described herein, it is preferred, but
not required that the worked fluid be limited to temperatures below
its atmospheric boiling point. Thus, it is preferred that the
systems be operated under vacuum. However, this is not required and
is left to the design considerations of the particular system being
implemented.
[0170] FIGS. 19A and 19B illustrate yet other embodiments utilizing
various aspects of the inventions disclosed and taught herein.
FIGS. 19A and 19B illustrate systems 1900 that may be used to
"pasteurize" a fluid, such as industrial or oil field fluids.
"Pasteurize," in the context of this disclosure, means to hold a
fluid at a temperature, or above a temperature, for a period, or
for at least a period, to destroy objectionable organisms in the
fluid, without causing major chemical or functional alteration of
the fluid. As an example, but without limitation or definition, a
fluid may be "pasteurized" using system 1900 by holding the fluid
for at least 15 seconds at a temperature of at least about
161.degree. F.
[0171] In general, the system 1900 heats a fluid, such as, but not
limited to, oil well fluids, to a temperature above 161.degree. F.
by passing the fluid through a fluid-to-fluid heat exchanger that
is coupled to a heating subsystem. The heated fluid may then be
flashed into its liquid and vapor forms through an orifice into a
holding tank, where the liquid is held for at least about 15
seconds and preferably longer. It is preferred, but not required,
that the tank be operated under negative pressure (i.e., a vacuum)
to, among other things, remove oxygen and other gasses from the
liquid. The vapor phase may pass through a demisting hood in which
entrained liquid is separated and returned to the tank. The vapor
(e.g., steam) may be passed to a fluid-to-fluid heat exchanger that
functions to transfer heat from the vapor to the incoming fluid
stream. The condensed vapor may be captured in a condensate
receiver. After the degassed liquid portion has been held in the
tank for 15 seconds or more at 161.degree. F. or higher, the liquid
portion may be removed and pumped through another fluid-to-fluid
heat exchanger that may also function to transfer heat from the
vapor to the incoming fluid stream and concomitantly cool the
degassed, pasteurized fluid. Although the vapor portion and the
degassed liquid portion may be used to heat (or preheat) the
incoming fluid, the majority of the heating may occur in the
fluid-to-fluid heat exchanger that that is coupled to a heating
subsystem, such as any of those previously described with reference
to FIGS. 1-18.
[0172] In this fashion, system 1900 is able to concentrate,
pasteurize, degas and/or de-oxygenate a fluid, to prevent or
minimize growth of objectionable aerobic and anaerobic organisms in
the fluid.
[0173] Without limitation, the specific embodiment shown in FIG.
19A utilizes a direct-fired, closed loop, heating cycle 1902. FIGS.
6 and 12 illustrate preferred embodiments of a direct-fired, closed
loop heating subsystems that may be used with system 1900. It will
be appreciated that other heating subsystems, such as one or more
of those disclosed herein, may be used based on the performance
objectives of system 1900 to be achieved. As shown in FIGS. 6 and
12, the closed-loop heating subsystem may comprise a natural gas or
other hydrocarbon-based boiler for heating a working fluid. It is
preferred that the direct-fired fluid heater 1904 be a 5,000,000
BTU/hour natural gas water heater. It is contemplated that in
certain applications the heater 1904 would be fired with waste gas
from an oil field metered into the heater 1904 through a pressure
control valve 1906. Therefore, it is desirable that the heater
1904-burner controls allow substantially real-time gas-to-air
adjustments to account for changing gas quality.
[0174] The working fluid in the closed-loop heating subsystem 1902
is preferably a 50/50 mixture of water and glycol. The heater 1904
may heat the working fluid to temperature T1, which may be, for
example, 210.degree. F. The heated working fluid is pumped 1908
through a fluid-to-fluid heat exchanger 1910 to transfer heat from
the working fluid to the worked fluid. Working fluid exits the heat
exchanger 1910 and enters an atmospheric reservoir or accumulator
1914. Pump 1908 draws working fluid out of the reservoir 1914 and
feeds it back to heater 1904. A temperature transducer T1
cooperates with controllable valve 1906 to control the temperature
of the working fluid.
[0175] The fluid 1903 to be pasteurized (aka the "worked fluid")
enters system 1900 at pump 1950, which may be, among other things,
a conventional centrifugal pump. A controllable valve 1952, such as
a globe valve, may be positioned after the pump 1950 to control the
temperature of the worked fluid exiting the heat exchanger 1910. As
shown in FIG. 19, a temperature transducer T3 adjacent the exit of
heat exchanger 1910 may be used to control valve 1952 in known
fashion.
[0176] Typically, the worked fluid 1903 will enter the system 1900
at temperature between about 40.degree. F. and 80.degree. F. It is
preferred, but not required that the incoming worked fluid 1903 be
pre-heated. One source of energy for a pre-heater is the
pasteurized worked fluid. As shown in FIG. 19A, the liquid portion
of worked fluid 1903 exits the flash tank 1928 at between about
161.degree. F. and 171.degree. F., and preferably about 162.degree.
F. It is often desirable to cool this pasteurized fluid before it
exits system 1900, and this fluid can be used to pre-heat the
incoming fluid. A fluid-to-fluid heat exchanger 1954 can be used to
transfer energy from the pasteurized fluid exiting the flash tank
1928 and to the incoming fluid. For example, and not for
limitation, worked fluid entering the pre-heater 1954 at about
162.degree. F. may be cooled to about 90.degree. F. and the
incoming fluid may be heated to about 130.degree. F.-132.degree.
F.
[0177] Similarly, as will be discussed in more detail below, the
vapor portion of the worked fluid from the flash tank 1928 can be
used to preheat (or heat) further the incoming fluid by passing the
vapor (e.g., steam) through a condensing heat exchanger 1932. For
example, the vapor portion of the worked fluid may exit the flash
tank at a temperature of about 162.degree. F. and transfer some of
its thermal energy in heat exchanger 1932 to the worked fluid,
raising its temperature to about 142.degree. F.
[0178] Regardless of the number of preheating stages used and
regardless of the temperature of the incoming fluid, the worked
fluid is primarily heated in fluid-to-fluid heat exchanger 1910
which thermally couples the incoming worked fluid 1903 to the
heating subsystem 1902. The temperature of the worked fluid exiting
the primary heat exchanger 1910 may be controlled by inlet valve
1952, which may be controlled based on the temperature of the
exiting worked fluid. As discussed above, it is preferred that the
temperature of the worked fluid exiting the primary heat exchanger
1910 is above 161.degree. F. and preferably is about 172.degree. F.
It has been found that at temperatures above about 175.degree. F.,
scaling of the internal surfaces of the heat exchangers and flash
tank may occur. Once the worked fluid is at temperature, it is
flashed into its vapor and liquid portions through orifice 1956 and
into flash tank 1928. A baffle 1958 may be located in flash tank
1928. The liquid portion of the worked fluid 1903 settles in the
bottom of the flash tank 1928 as shown in FIG. 19. A liquid level
transducer 1960, such as a guided wave transducer may be used to
sense the liquid level in the tank.1928. Once the liquid level in
the flash tank reaches a certain height, such as, for example,
halfway, pump 1962 and controllable valve 1964 are energized and
opened to extract pasteurized liquid from the flash tank 1928,
which fluid may be passed through pre-heater 1954, as previously
described, to both preheat the incoming fluid and cool the exiting
worked fluid.
[0179] It will be appreciated that holding the worked fluid in
flash tank 1928 at a temperature of about 172.degree. F. for a
period greater than 15 seconds will effectively pasteurize the
worked fluid and kill all or substantially all of the aerobic and
anaerobic objectionable organisms that may exist in the fluid.
[0180] In addition, it is preferred that the flash tank 1928 be
operated at a sub-atmospheric pressure, such as, but not limited to
18 inches of vacuum. By operating the flash tank under a vacuum,
oxygen and other gasses will be removed from the liquid portion of
the worked fluid, along with the vapor portion of the worked fluid.
It will be appreciated that by depleting or decreasing the amount
of oxygen in the worked fluid, objectionable organisms may be
destroyed and/or the ability of objectionable organisms to grow in
the worked fluid will be minimized. The liquid may be agitated in
known manner, as necessary, to achieve maximum de-oxygenation of
the fluid.
[0181] As previously discussed, the vapor phase of the worked fluid
and any gasses removed from the liquid portion of the worked fluid
will pass through demister hood 1966 in which any entrained liquid
will be separated from the vapor and returned to the flash tank.
Thereafter, the vapor (e.g., steam) may be passed through a
condensing heat exchanger to condense the vapor to its liquid form
(e.g., distilled water) and concomitantly transfer heat to the
incoming fluid. The exit of the condenser 1932 may be coupled to a
condensate receiver and vacuum pump 1968. Any non-condensable
gasses, such as oxygen, nitrogen (air) and light hydrocarbons may
be passed to, for example, the direct fired boiler for incineration
or combustion.
[0182] Having now described the basic layout of the embodiment
shown in FIG. 19A, it will be appreciated that during startup of
the system, exit valve 1970 may be closed and bypass valve 1972 may
be opened so that an amount of incoming fluid 1903 may be
circulated through the system until the fluid reaches predetermined
temperature T3 of about, for example, 172.degree. F. Once the
system reaches its designed operating conditions, exit valve 1970
may be opened and bypass valve 1972 may be closed. At that point,
control of the system is accomplished by temperature T3 at the
outlet of the primary heat exchanger 1910 and associated controlled
valve 1952 and liquid level control 1960 and its associated valve
1964.
[0183] The system 1900 functions as a chemical-free purification
system for highly contaminated industrial fluids, such as raw water
intended to be used as frac water. The system 1900 effectively
removes/kills bacterial contaminates, free oxygen and the majority
of grease and oils. It virtually eliminates the need for massive
quantities of expensive and toxic biocides and oxygen
scavengers.
[0184] Field testing of a prototype has demonstrated results of
effectively reducing total live bacterial cell count from
contaminated water at 369,100 cells per ML to under 500 cells per
ML, without using chemical treatment agents;
[0185] reducing dissolved oxygen from 12 PPM to under 1.5 PPM; and
reducing grease and oils from 831 mg/ml to 2.4 mg/ml, and
incinerates hydrocarbons in the process.
[0186] The system 1900 can be designed to heat frac fluids
20.degree. F. at 12 bbl per minute. Higher heating rates are
achievable, up to about 60.degree. F., but at lower flow rates. The
countercurrent, cold and heated fluid flows allow the system to
heat fluids at high temperatures for bacterial elimination and then
transfer the heat to the incoming cold fluid. The system functions
economically and is cross-exchanged for energy efficiency. Total
energy cost for natural gas and grid power rate is estimated at
approximately $0.05/bbl. Using generator power and propane, costs
to operate are approximately $0.15 per bbl. Further, up to three
systems can be operated in parallel from a single control station
by a single operator.
[0187] The system 1900 of FIG. 19A utilizes a closed loop,
direct-fired hot water boiler system, isolating worked fluids from
the high temperature boiler tubes that are exposed to the direct
flames. Waters to be processed are heated by closed loop titanium
Tranter.RTM. plate and frame heat exchanger. It is presently
desired to keep fluid temperatures below the scale forming
temperatures of most contaminated waters to be processed. After
waters have been processed through the heat exchanger, they are
then circulated through an orifice into a high vacuum flash tank.
In the flash tank, the superheated waters flash off steam, which is
condensed in a plate and frame heat exchanger cooled by
cross-exchange with the cold, raw, contaminated water entering the
system, thus recovering the majority of the treatment energy. Under
the temperature, vacuum, and during the retention time encountered
in the flash tank phase, the water is pasteurized and degassed,
killing the organisms by heat and vacuum, and removing oxygen and
volatile hydrocarbons. All of the vapors not condensed may be
passed to the direct-fired boiler's firebox and are incinerated and
harmlessly discharged into the atmosphere. The system 1900
facilitates de-aeration of fluid, e.g., O.sub.2 removal at
175.degree. F. and 21 to 23'' Hg vacuum.
[0188] The pasteurizing system 1900 illustrated in FIG. 19B is
similar to the system 1900 illustrated in FIG. 19A, and except as
noted below, the description for FIG. 19A applies generally to FIG.
19B. In the system 1900 shown in FIG. 19B, the incoming
contaminated fluid is pumped through the steam condenser 1996 to
condense the steam that flashes out of tank 1928. The condensate is
received in vacuum receiver 1968. The contaminated fluid exits the
condenser at about 94.degree. F. and enters preheater 1998, which
transfer heat from the blowdown from flash tank 193 to the
contaminated fluid. The contaminated fluid exits the preheater at
about 159.degree. F., which can be controlled by valve 1994, and
enters the primary heat exchanger 1910 to raise the temperature of
the contaminated fluid to about 169.degree. F. The heated
contaminated fluid is flashed into tank 1928 where it resides at
about 165.degree. F. for a period determined by valve 1992
sufficient to eliminate or reduce objectionable organisms. The
system 1900 of FIG. 19B is configured to generated 2,000 lbs of
steam at about 165.degree. F. Thus, FIGS. 19A and 19B illustrate
another aspect of the present inventions for heating and
manipulating fluids.
[0189] FIGS. 20A and 20B illustrate yet other embodiments of one or
more of the inventions disclosed herein. More specifically, FIG.
20A shows system 2000 that may be used to heat fluid 2011, such as
industrial or oil field fluids; and to pump or inject such fluids
under high pressure. The system 2000 may comprise a closed-loop
heating subsystem 2003 having a 600 kw diesel genset 2001
comprising a diesel engine 2002, which is preferably a 600
horsepower, Tier III, turbocharged, diesel engine coupled to an
electric generator 2005 supplying, for example, 480 volt, 3-phase
electricity 2007 The heating subsystem 2003 may also comprise a
working fluid tank 2010, an electric boiler 2009, and a primary
heat exchanger 2006, all plumbed in closed-loop fluid
communication; an engine water jacket heat exchanger 2015; and an
engine exhaust gas heat exchanger 2016. The fluid to be heated 2011
is plumbed through each of the heat exchangers as shown in FIG.
20A, such that the fluid may exit the primary heat exchanger 2006
at the desired or predetermined temperature. The system 2000 also
may include a high pressure pump 2050, such as, but not limited to
a Gardner Denver 200 Hp kill pump, or other type of pump, including
other variable speed, plunger style kill pumps.
[0190] The engine water jacket heat exchanger 2015 may be a
fluid-to-fluid heat exchanger, such as a plate and frame heat
exchanger. One flow path is coupled to the diesel engine 2002 water
jacket and engine radiator 2034. A second flow path couples the
diesel engine 2002 water jacket and the water jacket heat exchanger
2015. It will be appreciated, as shown, that controllable (or
manual) valves may be placed in the flow paths to force the water
jacket coolant to flow solely through the engine radiator 2034, or
to also flow through the water jacket heat exchanger 2015. It will
be understood that when coolant flows through the heat exchanger
2015, heat may be transferred to the incoming fluid 2011.
Alternately, when the heat exchanger 2015, is bypassed, the
incoming fluid 2011 will not be pre-heated by heat exchanger
2015.
[0191] The engine exhaust 2013 may also be used as a source of heat
to preheat or heat incoming fluid 2011. As shown in FIG. 20A,
controllable (or manual) valves may direct the engine exhaust to a
conventional muffler or muffler/catalyst exhaust system 2017 or to
an air (i.e., exhaust gas)-to-fluid heat exchanger 2016.
[0192] Primary heating of the fluid 2011 occurs in primary heat
exchanger 2006. Electricity 2007 from the generator 2005 powers the
boiler 2009. The boiler 2009 heats the working fluid in the heating
subsystem to a predetermined temperature T1 and then directs the
heated fluid to a fluid-to-fluid heat exchanger 2006, such as a
plate and frame heat exchanger, to heat the incoming fluid 2011.
Cooled working fluid exits the heat exchanger 2006 and flows to a
tank 2010. For the embodiment of FIG. 20A, the tank 2010 is
un-pressurized and vented to atmosphere, thereby operating at
atmospheric conditions. The boiler working fluid is preferably a
glycol and water mixture and is drawn from the tank 2010 by pump
2008 and pumped back to boiler 2009.
[0193] It will now be appreciated that system 2000 may be used to
circulate a fluid 2052 into a tank (not shown) by running the
diesel engine 2002 and generator 2005 to power incoming fluid pump
2019. Circulation of fluid 2011 can include, optionally, heating of
the fluid as described above. Additionally, system 2000 can be used
to inject high-pressure fluid 2054 into a well or other structure.
High pressure injection of fluid 2054 can include, optionally,
heating of the fluid as described above. FIG. 20B illustrates the
system 2000 of FIG. 20A disposed on a conventional trailer of an 18
wheel tractor/trailer combination.
[0194] FIGS. 21A and 21B illustrate embodiments of the present
inventions that are useful to recover, recycle and/or dispose of
water-containing industrial fluids, such as, but not limited to,
produced water or flowback water, by vacuum evaporation,
de-aeration and/or pasteurization. It is contemplated that a
system, such as described and shown in FIGS. 21A and 21B, can
process about 13,600 barrels/day of fluid, assuming the fluid is
about 60,000 ppm TDS (predominately NaCl).
[0195] As illustrated in FIGS. 21A and 21B, system 2100 may be
modular in nature and construction to allow adjustability in
capacity and to increase transportability. For example, and without
limitation, the system 2100 may comprise multiple, such as six,
evaporation systems 2110. In FIG. 21A, any of the evaporation
systems illustrated in FIGS. 7 through 12B may be used. Preferably,
the embodiment of FIG. 21A utilizes an evaporation system 2110 such
as described and illustrated in FIG. 12A, including evaporation
towers 2112. Preferably, the embodiment of FIG. 21B uses a
multiple-effect evaporator system 2110 such as described and
illustrated in FIG. 12B. By combining multiple evaporator systems
2110 in this manner, my inventions can be scaled to a particular
job based on the amount of fluid to be treated, the location of the
job and other such factors.
[0196] It will be seen from FIGS. 21A and 21B that contaminated
fluid 2102, such as produced water may enter the modular system
2100 at a first process point 2104, which may include
hydrocyclones, oil skimmers, filters and other devices configured
to remove particulate and other macro contaminants from the fluid.
Solid and/or particulates removed from the fluid may be passed to a
landfill or otherwise properly disposed of. Any oil recovered from
the fluid 2102 may be commercialized or disposed of as allowed or
desired. A portion 2106 of the fluid 2102 may then be passed to the
evaporation systems 2110 previously described to remove and/or
disposed of, through evaporation, a desired portion of the fluid
2102. As described for the evaporation systems illustrated in FIGS.
7-12B, in the case of produced water, the evaporation systems 2110
will produce a concentrated fluid 2114, such as brine or 10 lb
brine, which may be sold or disposed of as desired and/or
allowed.
[0197] In addition, as described for the evaporation systems
illustrated in FIGS. 7-12B, the evaporation systems 2110 will
produce distilled water or condensate 2116, which may be sold or
disposed of or used as desired and/or allowed. Use of condensate
2116 by process 2100 will be described below.
[0198] Another portion 2108 of the water 2102 may be passed to a
pasteurization system 2120, such as any one of the systems
described and illustrated in FIGS. 19A and 19B. Once the fluid 2102
has been pasteurized, it may be blended with condensate 2116, as
desired or needed, to produce frac water for use or sale.
[0199] Thus, the systems 2100 illustrated in FIGS. 21A and 21B may
utilize various aspects of my inventions disclosed and taught
herein to dispose of fluid by evaporation; to generate condensate
for use or sale; to pasteurize fluid for use or sale; and to reduce
the amount of remaining fluid or solids that need to be disposed
of.
[0200] My inventions have been described in the context of
preferred and other embodiments and not every possible embodiment
of the invention has been described. A person of skill in this art
having the benefit of this disclosure will now be able to mix and
match various aspects of the embodiments described herein to
accomplish a particular task. A person of skill will also be able
to take the teachings of this disclosure and rearrange components
within an embodiment or take components from other embodiments to
create new embodiments, all without departing form the spirit of my
inventions or the scope of the appended claims. For example, and
without limitation, a person of skill having benefit of this
disclosure will appreciate and understand that any of the heating
subsystems described and illustrated in FIGS. 1 through 6B may be
used with any of the fluid evaporation systems or subsystems
described and illustrated in FIGS. 7 through 12C; or with any of
the fluid concentration systems or subsystems described and
illustrated in FIGS. 13 through 16; or with any of the fluid
fractioning systems or subsystems described and illustrated in
FIGS. 17 and 18; or with any of the fluid pasteurizing systems or
subsystems described and illustrated in FIGS. 19A and 19B; any of
the fluid systems or subsystems described and illustrated in FIGS.
20A through 21B. Those person of skill having benefit of this
disclosure will be encouraged to combine these various systems and
subsystems to achieve the functional and operational targets for
each implementation of my inventions. In addition, various of these
systems and subsystems, such as, but not limited to, when used to
produce frac water from produced water, may benefit from
conventional filtration techniques including mechanical filtration
and/or reverse osmosis filtration. While a developer's efforts to
select and combine these various systems and subsystems might be
complex and time-consuming, such efforts would be, nevertheless, a
normal undertaking for those of ordinary skill in the art having
benefit of this disclosure.
[0201] It will be appreciated that the fluid transporting conduits
used with embodiments of the present invention may comprise piping,
tubing and other fluid communications means of conventional and
unconventional design and material. For most systems described
herein it is preferred that the piping material be carbon steel,
when possible. Of course, the operating environment may dictate the
material that is used. The circulation pumps may be of any
conventional or unconventional design, but for the produced water
embodiment described herein, it is preferred that the pumps be
hydraulic, pneumatic, electrical or direct drive (e.g., engine PTO)
centrifugal pumps. Metering or positive displacement pumps, such
as, but not limited to, Moyno pumps, may be used at various
locations throughout the system as desired or required by the
specific implementation. Detection or determination of system
properties or characteristics, such as, but not limited to,
pressure, temperature, density, flow rate, or Total Dissolved
Solids, may be acquired through conventional instrumentation and
data acquisition techniques, including manual techniques, as are
well known to those of skill in the art.
[0202] Modifications and alterations to the described embodiments
are now readily available and apparent to those of skill in the
art. The disclosed and undisclosed embodiments are not intended to
limit or restrict the scope or applicability of the inventions
conceived of, but rather, in conformity with the patent laws, I
intend to protect all such modifications and improvements to the
full extent that such falls within the scope or range of
equivalents of the following claims. If a word or phrase used in a
claim does not appear in reference to a figure herein, and such
word or phrase has no specialized meaning in the relevant art, then
any such word should be construed according to its ordinary and
customary meaning and any such phrase should be construed according
to the ordinary and customary meaning of each word in the
phrase.
* * * * *