U.S. patent application number 10/983356 was filed with the patent office on 2005-06-09 for apparatus and method for draining reservoirs.
Invention is credited to Davis, Patrick Neal, Smith, Henry A. III.
Application Number | 20050123425 10/983356 |
Document ID | / |
Family ID | 34636397 |
Filed Date | 2005-06-09 |
United States Patent
Application |
20050123425 |
Kind Code |
A1 |
Smith, Henry A. III ; et
al. |
June 9, 2005 |
Apparatus and method for draining reservoirs
Abstract
An apparatus for draining reservoirs includes a pump disposed in
contact with a lower surface of the vessel to be drained, wherein
the pump is connected to a discharge pipe inserted into the vessel
through an insertion tube connected to a retrofit assembly of the
vessel. The apparatus also includes seals within the insertion tube
and within the discharge pipe to prevent gases from within the
vessel from passing through the insertion tube and discharge pipe
and into the atmosphere. An expansion joint unit attaches to the
discharge pipe to prevent the rotation of the pump relative to the
discharge pipe. The expansion joint unit also maintains the pump in
substantial contact with the lower surface of the vessel even when
thermal expansion causes the vessel to expand and the position of
the discharge pipe to lift.
Inventors: |
Smith, Henry A. III;
(Tustin, CA) ; Davis, Patrick Neal; (Somerset,
GB) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
2040 MAIN STREET
FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Family ID: |
34636397 |
Appl. No.: |
10/983356 |
Filed: |
November 8, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60518376 |
Nov 7, 2003 |
|
|
|
Current U.S.
Class: |
417/424.1 ;
417/423.3; 417/53 |
Current CPC
Class: |
F17C 2223/036 20130101;
F17C 2223/033 20130101; F17C 2205/0335 20130101; F17C 2250/032
20130101; F17C 2221/033 20130101; F17C 2205/0329 20130101; F17C
2260/044 20130101; Y02E 60/321 20130101; F17C 2223/035 20130101;
F04D 13/08 20130101; F17C 2260/036 20130101; F17C 2201/032
20130101; Y02E 60/32 20130101; F17C 2201/052 20130101; F17C
2260/013 20130101; F04D 7/02 20130101; F17C 2227/0178 20130101;
F17C 2201/0109 20130101; F17C 2201/0119 20130101; F17C 2205/0323
20130101; F17C 2221/012 20130101; F17C 2250/0636 20130101; F17C
2270/05 20130101; F17C 2201/054 20130101; F17C 2205/0385 20130101;
F17C 2205/0326 20130101; F04B 15/08 20130101; F17C 2223/047
20130101; F17C 2260/021 20130101; F17C 2223/0123 20130101; F17C
2223/0161 20130101; F17C 2250/043 20130101; F17C 7/00 20130101;
F17C 2227/0135 20130101 |
Class at
Publication: |
417/424.1 ;
417/423.3; 417/053 |
International
Class: |
F04B 001/00; F04B
017/00 |
Claims
What is claimed is:
1. A method for removing residual cryogenic liquid from a cryogenic
reservoir having an instrumentation access duct with a measurement
instrument configured to be lowered into the reservoir, comprising
the steps of: removing the measurement instrument from the
instrumentation access duct; installing a first valve to an upper
end of the instrumentation access duct, the first valve having at
least a closed position in which the interior of the reservoir is
sealed from the atmosphere; attaching an adapter member upstream of
the first valve with the first valve in a closed position;
inserting a first end of a first pump discharge pipe into an
insertion tube so as to generate a seal between the first pump
discharge pipe and an interior surface of the insertion tube and
with the interior of the first pump discharge pipe being blocked,
the first pump discharge pipe also including a pump at the first
end; inserting the insertion tube into the adapter member so as to
generate a seal between an outer surface of the insertion tube and
an inner surface of the adapter member; opening the first valve;
inserting a downstream end of the insertion tube through the first
valve; connecting at least a second pump discharge pipe to a second
end of the first pump discharge pipe with an interior of the second
pump discharge pipe being blocked; unblocking the first pump
discharge pipe; inserting at least a portion of the second pump
discharge pipe through the first valve; connecting a second end of
the second pump discharge pipe to a cryogenic liquid recovery
device; and operating the pump so as to draw cryogenic liquid from
the reservoir and pump the liquid through the first and second pump
discharge pipes and into the cryogenic liquid recovery device.
2. A method for draining a reservoir, comprising the steps of:
attaching an adapter member to a vessel housing a fluid; sealingly
inserting an insertion tube through said adapter member and into
said vessel; sealingly inserting at least one discharge pipe
through said insertion tube into said vessel, wherein the discharge
pipe is connected to a pump assembly; advancing the at least one
discharge pipe through the insertion tube to dispose the pump
assembly proximal a lower surface of the vessel; and pumping the
fluid through said at least one discharge pipe to a desired
location.
3. The method of claim 2, further comprising the step of:
circulating an inert gas between the insertion tube and the at
least one discharge pipe.
4. The method of claim 2, further comprising the step of:
selectively actuating a movable seal, wherein at least a portion of
the movable seal is disposed in the discharge pipe, to
substantially prevent fluid flow through the discharge pipe.
5. The method of claim 4, wherein the movable seal is a valve.
6. A retrofit pump assembly for draining a reservoir, comprising:
an adapter member configured for attachment to a vessel that houses
a fluid; an insertion duct configured to be slidably and sealedly
insertable through said adapter member into said vessel; at least
one discharge pipe configured to be sealedly slidable into said
adapter member; and a pump assembly connected to one end of the at
least one discharge pipe.
7. The retrofit pump assembly of claim 6, wherein the pump assembly
is disposed adjacent the lower surface of the vessel.
8. The retrofit pump assembly of claim 6, wherein the pump assembly
comprises: a motor; and a pump disposed below said motor and driven
by said motor.
9. The retrofit pump assembly of claim 6, further comprising at
least one seal disposed between the insertion tube and the adapter
member, the seal configured to substantially prevent fluid flow
between the insertion tube and the adapter member.
10. The retrofit pump assembly of claim 9, wherein the seal is an
O-ring.
11. The retrofit pump assembly of claim 6, further comprising a
movable seal, wherein at least a portion of the movable seal is
disposed in the discharge pipe, the movable seal selectively
actuatable to substantially prevent fluid flow through the
discharge pipe.
12. The retrofit pump assembly of claim 11, wherein the movable
seal is a balloon.
13. The retrofit pump assembly of claim 11, wherein the movable
seal is a valve.
14. The retrofit pump assembly of claim 6, further comprising means
for circulating an inert gas between the insertion tube and the at
least one discharge pipe.
15. A retrofit pump assembly for draining a reservoir, comprising:
an adapter member configured for attachment to a vessel that houses
a fluid; an insertion tube sized for insertion through said adapter
member into said vessel; at least one discharge pipe connected to
said adapter member and extending through said insertion tube into
said vessel; at least one sealing assembly disposed between the
discharge pipe and the insertion tube and configured to
substantially prevent fluid flow through the insertion tube; an
expansion joint unit connected to the at least one discharge pipe;
and a pump assembly connected to the expansion joint unit and
disposed proximal a lower surface of the vessel, the pump assembly
configured to pump fluid from said vessel through said discharge
pipe to a desired location, wherein the expansion joint unit is
configured to allow an expansion of the at least one discharge pipe
and to maintain the pump assembly substantially proximal to the
lower surface of the vessel.
16. The retrofit pump assembly of claim 15, wherein the expansion
joint unit is configured to allow the at least one discharge pipe
to expand about one foot.
Description
RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional
Application No. 60/518,376, which was filed on Nov. 7, 2003, the
entirety of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTIONS
[0002] 1. Field of the Inventions
[0003] The present embodiments generally relate to systems and
methods for draining reservoirs, and more particularly, pump
assemblies for draining large reservoirs of cryogenic liquids.
[0004] 2. Description of the Related Art
[0005] In certain areas of the art of the storage of cryogenic
liquids, enormous storage tanks have been constructed with
permanently installed high-volume pumps. For example, in the art of
utility-scale liquid natural gas storage, storage tanks have been
constructed with a diameter of approximately the size of half of a
city block and with a height of about 175-feet. A schematic
illustration of such a tank is illustrated in FIG. 1.
[0006] As shown in FIG. 1, a conventional liquid natural gas
storage tank 10 includes an outer tank wall 12 including a
generally cylindrical sidewall 14, a flat bottom 16, and a domed
top 18. The bottom 16 can be placed on the ground or can be
suspended above the ground by pylons 20.
[0007] Within the outer tank wall 12, an inner vessel 22 is defined
by an inner tank sidewall 24 and a bottom wall 26. The sidewall 24
can be generally cylindrical in shape, corresponding to the shape
of the outer wall 14. Similarly, the bottom wall 26 can be flat
corresponding with the shape of the lower wall 16.
[0008] The upper end of the inner vessel 22 is open. A lid assembly
28 typically is suspended from the domed top 18 by a plurality of
struts 30. A seal 32 extends between the lid assembly 28 and the
sidewall 24 of the vessel 22. As such, the vessel 22 is sealed, and
thus can store a fluid therein. In the illustrated tank 10, the
fluid within the vessel 22 includes some liquid natural gas LNG and
gaseous natural gas GNG above the liquid natural gas LNG.
[0009] Between the outer tank wall 12 and the inner vessel 22,
insulation typically is disposed. For example, between the lower
walls 16, 26, a rigid insulation 34 typically is disposed.
Additionally, a lighter or fluffier insulation 36 can be disposed
between the lateral walls 14, 24. Additional insulation can be
disposed within the lid assembly 28. Insulated as such, the tank 10
can better maintain the fluid within the vessel 22 at the desired
temperature. In the art of the storage of cryogenic liquids, it is
desirable to maintain the fluid at a temperature at which the
liquid state of the liquid can be maintained. For example, with
liquid natural gas LNG, the vessel 22 can be maintained at
approximately -260.degree. F. or lower. Other substances can be
maintained in a liquid state at other temperatures.
[0010] As noted above, tanks such as the tank 10 are often
extremely large. Additionally, such cryogenic liquids cannot be
vacuumed out of such a tank. This is because when such a liquid is
subject to a large vacuum, the liquid boils and therefore will not
travel up a vacuum pipe and out of such a tank. Additionally, it is
generally undesirable to provide a drain pipe at the bottom of such
a tank 10. If such a drain pipe were to fail, enormous amounts of
liquid material, such as liquid natural gas LNG, could spill out of
such a tank 10, and thereby cause a dangerous situation. Thus,
tanks such as the tank 10 typically include a pump 40 mounted near
the bottom of the vessel 22 with a discharge of the pump 40
extending upwardly out of the domed top 18. In the illustrated
arrangement, the discharge pipe 42 is illustrated schematically and
extends to a discharge nozzle 44 above the domed top 18.
[0011] In order to provide a reasonable discharge speed of the
liquid natural gas LNG, the pump 40 is quite large in size and has
a high horsepower rating. Additionally, the motor 40 must be sealed
and be made from a proper material to be operated in the liquid
environment of the liquid natural gas LNG and at the environmental
temperature of approximately -200.degree. F. Typically, the motor
40 is suspended by the discharge pipe 42. Thus, as noted above,
because the tank can be approximately 175 ft. tall, the discharge
duct 42 is made from a thick, high strength material that is
appropriate for a cryogenic environment. For example, the discharge
pipe 42 can be made from stainless steel or aluminum.
[0012] As illustrated in FIG. 1, the discharge pipe 42 has a lower
portion that can be submerged below the level of the liquid natural
gas and an upper portion, adjacent the discharge nozzle 44, that is
exposed to the atmosphere. Thus, the discharge pipe 42 is subject
to substantial expansion, contraction, as well as thermal stresses.
In order to prevent the discharge pipe 42 from contacting the lower
surface 26 of the vessel 22, a clearance C is defined between the
lower end of the discharge pipe 42 and the lower wall 26. In many
typical tanks such as the tank 10, the clearance C can be as much
as 18 to 24 inches or more.
[0013] The tank 10 also includes an instrumentation assembly 50.
The instrumentation assembly 50 includes an instrument guide duct
52 extending through the domed top 18 and the lid assembly 28 into
the vessel 22, a valve 54, an instrument head 56, and at least one
instrument 58 configured to detect a state of the material within
the vessel 22.
[0014] The instrument guide tube 52 can be made from any material.
However, typically, the instrument guide tube 52 is made from a
stainless steel pipe having an inner diameter of between 5{fraction
(1/2)} inches and 10 inches. The instrument 58 is suspended from
the instrument head 56 by a cable 60. The instrument head 56 can
include a winch 62 configured to raise and lower the instrument 58
through the instrument guide tube 52. The valve 54 can be
configured to allow the instrument 58 to be retracted entirely into
the instrument head 56. For example, the valve 54 can be a "gate"
type valve. With such a valve, when the valve is open, the passage
extending through the valve 54 is completely open through the
entire bore through the valve 54. Alternatively, the valve 54 can
be a butterfly-type valve. With a butterfly-type valve, when such a
valve is open, the pivot shaft and valve plate remain within the
bore of the valve 54, thereby partially obstructing the passage
therethrough.
[0015] When a tank such as the tank 10 reaches the end of its
useful life, it is typically emptied of liquid natural gas LNG and
subsequently decommissioned and/or disassembled. Initially, the
liquid natural gas LNG will be pumped out of the vessel 22 by the
existing pump 40. However, as noted above, the resulting clearance
C prevents the pump 40 from reaching residual liquid natural gas
RLNG at the bottom of the vessel 22. Because the clearance C can be
large, as noted above, the volume of residual liquid natural gas
RLNG can be quite large.
[0016] One way to remove the residual liquid natural gas is to
allow it to evaporate out of the tank through existing plumbing.
Typically, it can take approximately three months to allow such a
volume of residual liquid natural gas LNG to evaporate out of the
tank 10. Additionally, such an evaporation process must be
monitored to ensure public safety. Thus, the process of
decommissioning a tank, such as the tank 10, can be a long
process.
SUMMARY OF THE INVENTION
[0017] In one aspect of at least one of the inventions disclosed
herein, a method for removing residual cryogenic liquid from a
cryogenic reservoir having an instrumentation access duct with a
measurement instrument configured to be lowered into the reservoir
is provided. The method comprises the steps of removing the
measurement instrument from the instrumentation access duct and
installing a first valve to an upper end of the instrumentation
access duct. The first valve has at least a closed position in
which the interior of the reservoir is sealed from the atmosphere.
A adapter member is attached upstream of the first valve with the
first valve in a closed position. The method also includes
inserting a first end of a first pump discharge pipe into an
insertion tube so as to generate a seal between the first pump
discharge pipe and an interior surface of the insertion tube and
with the interior of the first pump discharge pipe being blocked,
the first pump discharge pipe also including a pump at the first
end. The insertion tube is inserted into the adapter member so as
to generate a seal between an outer surface of the insertion tube
and an inner surface of the adapter member, and the first valve is
opened. A downstream end of the insertion tube is inserted through
the first valve. At least a second pump discharge pipe is connected
to a second end of the first pump discharge pipe with an interior
of the second pump discharge pipe being blocked and the first pump
discharge pipe is unblocked. At least a portion of the second pump
discharge pipe is inserted through the first valve. A second end of
the second pump discharge pipe is connected to a cryogenic liquid
recovery device. Additionally, the pump is operated so as to draw
cryogenic liquid from the reservoir and pump the liquid through the
first and second pump discharge pipes and into the cryogenic liquid
recovery device.
[0018] In another aspect of at least one of the inventions
disclosed herein, a method for draining a reservoir is provided.
The method includes attaching an adapter member to a vessel housing
a fluid and sealingly inserting an insertion tube through said
adapter member and into said vessel. At least one discharge pipe is
sealingly inserted through said insertion tube into said vessel,
wherein the discharge pipe is connected to a pump assembly. The at
least one discharge pipe is advanced through the insertion tube to
dispose the pump assembly proximal a lower surface of the vessel.
Additionally, the fluid is pumped through said at least one
discharge pipe to a desired location.
[0019] In another aspect of at least one of the inventions
disclosed herein, a retrofit pump assembly for draining a reservoir
is provided. The retrofit pump assembly comprises an adapter member
configured for attachment to a vessel housing a fluid and an
insertion tube sized for insertion through the adapter member into
the vessel. The retrofit pump assembly also comprises at least one
discharge pipe that connects to the adapter member and extends
through the insertion tube and into the vessel. At least one
sealing assembly is also provided, wherein the sealing assembly is
disposed between the discharge pipe and the insertion tube and is
configured to substantially prevent fluid flow through the
insertion tube. The retrofit pump assembly also comprises a pump
assembly connected to the discharge pipe and disposed proximal a
lower surface of the vessel, the pump assembly configured to pump
fluid from the vessel through the discharge pipe to a desired
location.
[0020] In another aspect of at least one of the inventions
disclosed herein, the retrofit pump assembly also comprises an
expansion joint unit disposed between the discharge pipe and the
pump assembly. The expansion joint unit is configured to allow the
expansion of the discharge pipe and to maintain the pump assembly
substantially proximal the lower surface of the vessel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a schematic and partial sectional view of a
conventional tank for storing liquid natural gas showing a pump, a
discharge pipe assembly and an instrumentation assembly.
[0022] The features mentioned above in the summary of the
invention, along with other features of the inventions disclosed
herein, are described below with reference to the drawings of the
preferred embodiments. The illustrated embodiments in the figures
listed below are intended to illustrate, but not to limit the
inventions. The drawings contain the following additional
figures:
[0023] FIG. 2 is a schematic and partial sectional view of the
conventional tank illustrated in FIG. 1, with the instrumentation
assembly removed and with a pump retrofit assembly installed
thereon;
[0024] FIG. 3 is a schematic and partial sectional view of the tank
and retrofit pump assembly illustrated in FIG. 2 with additional
sections being added to the retrofit pump assembly so that the pump
is disposed at a bottom of the tank;
[0025] FIG. 4 is a partial schematic and sectional view of the
retrofit pump assembly connected to the tank, an electronic drive
for the retrofit pump, and a discharge hose for discharging liquid
pumped from the tank;
[0026] FIG. 5 is an enlarged, schematic, and partial sectional view
of the retrofit pump assembly illustrated in FIG. 2 including an
adapter mounted on the valve on the tank, an insertion tube
extending from the adapter into the tank, a discharge pipe
extending through the insertion tube with a pump assembly disposed
at a lower end of the discharge pipe;
[0027] FIG. 6 is a perspective view of the adapter illustrated in
FIG. 5;
[0028] FIG. 7 is a top plan view of the adapter illustrated in FIG.
6;
[0029] FIG. 8 is a side elevational view of the adapter illustrated
in FIG. 6;
[0030] FIG. 9 is a sectional view of the adapter shown in FIG. 8
taken along line 9-9;
[0031] FIG. 10 is a side elevational view of the insertion tube
illustrated in FIG. 5;
[0032] FIG. 11 is a sectional view of the insertion tube
illustrated in FIG. 10 with the mounting flange removed;
[0033] FIG. 12 is a top plan view of the insertion tube illustrated
in FIG. 11;
[0034] FIG. 13 is an enlarged sectional view of the portion of the
insertion tube identified by the circle 13 in FIG. 11;
[0035] FIG. 14 is an enlarged portion of the insertion tube
identified by the circle 14 in FIG. 11;
[0036] FIG. 15 is a top plan view of the mounting flange of the
insertion tube illustrated in FIG. 10;
[0037] FIG. 16 is a side elevational view of the mounting flange
illustrated in FIG. 15;
[0038] FIG. 17 is a perspective view of a sealing disk mounted on
the retrofit pump assembly illustrated in FIG. 5;
[0039] FIG. 18 is a side elevational view of the sealing disk
illustrated in FIG. 17;
[0040] FIG. 19 is an enlarged view of the portion of the sealing
disk of FIG. 18 identified by the circle 19;
[0041] FIG. 20 is a top plan view of the sealing disk illustrated
in FIG. 17;
[0042] FIG. 20A is an enlarged, schematic, and partial sectional
view of an initial step in installing the retrofit pump assembly
into a tank;
[0043] FIG. 21 is a partial sectional and side elevational view of
the retrofit pump assembly illustrated in FIG. 5 with the discharge
pipe having been disconnected from the adapter and pulled partially
upward out of the adapter, along with a collar holding the
discharge pipe in the extracted position for aiding in assembling
additional discharge pipes;
[0044] FIG. 22 is a side elevational view of additional discharge
pipe sections to be connected to the discharge pipe illustrated in
FIG. 21;
[0045] FIG. 23 is a top plan view of the discharge pipe sectional
illustrated in FIG. 22;
[0046] FIG. 24 is an additional discharge pipe section, having a
length different from that of the discharge pipe illustrated in
FIG. 22;
[0047] FIG. 25 is a top plan view of the discharge pipe section as
illustrated in FIG. 24;
[0048] FIG. 26 is an enlarged side elevational and partial
sectional view of the upper end of the retrofit pump assembly
having been fully installed onto the tank 10;
[0049] FIG. 27 is an enlarged side elevational view of the upper
end of the discharge pipe illustrated in FIG. 26;
[0050] FIG. 28 is a bottom plan view of a lower flange disposed at
the lower end of the discharge pipe assembly illustrated in FIG.
27;
[0051] FIG. 29 is a side elevational and partial sectional view of
another retrofit pump assembly;
[0052] FIG. 30 is a side elevational and partial sectional view of
the assembly of FIG. 29 with the discharge pipe thereof having been
drawn out of the adapter assembly along with a collar for aiding in
the assembly of the discharge pipe to a further discharge pipe;
[0053] FIG. 31 is another embodiment of an additional discharge
pipe that can be connected to the discharge pipe illustrated in
FIG. 30;
[0054] FIG. 32 is a top plan view of the discharge pipe section
illustrated in FIG. 31;
[0055] FIG. 33 is a side elevational view of another discharge pipe
section having a length different from the discharge pipe section
illustrated in FIG. 31;
[0056] FIG. 34 is a top plan view of the discharge pipe section
illustrated in FIG. 33;
[0057] FIG. 35 is a side elevational and partial sectional view of
the upper end of the second retrofit pump assembly being fully
installed on the tank 10.
[0058] FIG. 35A is a side elevational and partial sectional view of
a modification of the retrofit pump assembly of FIG. 29 including
an optional anti-rotation device;
[0059] FIG. 36 is a cross-sectional view of an expansion joint unit
for use with the retrofit pump assembly.
[0060] FIG. 37A is a cross-sectional view of a pipe member of the
expansion joint unit.
[0061] FIG. 37B is a cross-sectional view of a connector of the
expansion joint unit.
[0062] FIG. 37C is a cross-sectional view of an assembly of the
pipe member shown in FIG. 37A and the connector shown in FIG.
37B.
[0063] FIG. 37D is an enlarged view of a cross-sectional portion of
the pipe member shown in 37C identified by the circle D.
[0064] FIG. 37E is a top view of the assembly of the pipe member
and connector shown in FIG. 37C.
[0065] FIG. 38A is a cross-sectional view of a connector of the
expansion joint unit.
[0066] FIG. 38B is a cross-sectional view of a support member of
the expansion joint unit.
[0067] FIG. 38C is a cross-sectional view of an assembly of the
connector illustrated in FIG. 38A and the support member
illustrated in FIG. 38B.
[0068] FIG. 38D is an enlarged view of the portion of the connector
of FIG. 38C identified by the circle D.
[0069] FIG. 38E is a top view of an assembly of the connector shown
in FIG. 38A and the support member shown in FIG. 38B
[0070] FIG. 39A is an elevational view of an anti-rotation device
of the expansion joint unit.
[0071] FIG. 39B is a top view of the anti-rotation device
illustrated in FIG. 39A.
[0072] FIG. 39C is a side elevational view of a beam member of the
anti-rotation device illustrated in FIG. 39A.
[0073] FIG. 39D is a top view of the beam member shown in FIG.
39C.
[0074] FIG. 39E is a top view of a flange member of the
anti-rotation device shown in FIG. 39A.
[0075] FIG. 39F is a cross-sectional side view of the flange member
shown in FIG. 39E.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0076] With reference to FIGS. 2-26, a retrofit pump assembly 100
is described for removing residual liquid natural gas RLNG from a
conventional liquid natural gas tank 10. The retrofit pump assembly
100 can be used with other types of tanks where it is desired to
remove liquid from the bottom thereof. The present retrofit pump
assembly 100 provides particular benefits for use in large storage
tanks for cryogenic liquids and thus is described in the
environment of a liquid natural gas storage tank. However, it is to
be understood that certain features, aspects, characteristics, and
benefits of the retrofit pump assembly 100 can be achieved when
used with other types of tanks.
[0077] As shown in FIG. 2, the instrument assembly 50 has been
removed from the valve 54 and the retrofit pump assembly 100 has
been inserted through the valve 54. Where it is desired to prevent
gas from exiting the vessel 22 through the guide tube 52, the valve
54 preferably is closed during the installation of the retrofit
pump assembly 100.
[0078] After the initial portion of the pump assembly 100 is
installed as shown in FIG. 2, additional sections of discharge pipe
can be inserted through the valve 54 until the pump assembly at the
lower end of the assembly 100 reaches the residual liquid natural
gas RLNG at the bottom of the vessel 22 (See FIG. 3).
[0079] FIG. 4 illustrates a further schematic representation of the
retrofit assembly 100 being fully installed into the tank 10 and
connected to a pump drive 102 and a discharge conduit 104 for
directing liquid pumped from the tank 10 to a desired location.
[0080] FIG. 4 schematically illustrates a pump assembly 106
disposed at a lower end of the assembly 100. The pump assembly 106
includes an electric motor 108 driving a pump 110. In the
illustrated embodiment, the pump 110 is disposed below the motor
108 so as to achieve a lowest possible position within the tank 10
adjacent the bottom wall 26 of the tank 10. As such, the pump 110
can remove a maximum amount of residual liquid natural gas RLNG
from the vessel 22. Preferably, the pump 110 includes an inducer to
aid in feeding the pump 110 with liquid. Of course, any suitable
pump 110 and motor 108 can be used.
[0081] The size and capacity and performance of the pump 110 and
motor 108 will depend on the size of the guide tube 52, the type of
valve 54, (i.e., full bore, such as reciprocating ball or gate-type
valve, or obstructed flow, e.g., butterfly-type valve), the height
of the tank 10, the type of liquid to be pumped from the vessel 22,
and the desired flow rate. For certain typical liquid natural gas
applications, the pump 110 and motor 108 preferably are configured
to deliver 20 gallons per minute at 180 ft. of head. However, this
is merely an exemplary pump capacity. Other pump capacities can be
used depending on the desired speed.
[0082] In the illustrated embodiment, the motor drive 102 is a
variable frequency drive. However, this is merely one type of drive
that can be used for a particular electric motor 108. Other types
of motors 108 can be used and other types of drives 102 can be
used. It is to be noted that an electrical conduit 112 extending
from the drive 102 to the electric motor 108 should be sealed in
accordance with normal techniques well known in the art for
preventing gases or liquids from traveling between the insulation
of the conduit 112 and the electrical conductor extending
therethrough and thereby flowing out of the tank 10 and into the
junction boxes, e.g., junction boxes 114, 116, or into the drive
102.
[0083] FIG. 5 illustrates the retrofit assembly 100 in an initial
stage of installation onto the tank 10. As shown in FIG. 5, the
valve 54 is a gate-type full bore valve. Thus, the passage through
the valve 54 is completely unobstructed when in an open position. A
valve member 120 is illustrated in a retracted position indicating
an open position of the valve 54. It is to be noted that the valve
54 is constructed in accordance with typical plumbing tolerances.
Thus, the valve 54 typically will not include polished inner
surfaces. Rather, the inner surfaces of the valve 54 are likely to
be somewhat rough, depending on the manufacturing method used.
[0084] At its upper end, the retrofit assembly 100 includes an
adapter member 122. The adapter member 122 is attached to an upper
end of the valve 54. The adapter member 122 preferably includes an
inner diameter that is approximately equal to that of the valve
54.
[0085] An insertion tube 124 extends through the adapter 122, the
valve 54, through the instrument guide tube 52, and into the vessel
22 of the tank 10. As shown in FIG. 5, the electric motor 108 and
pump 110 are connected to a discharge pipe 126. The discharge pipe
126 is fluidly connected with the pump 110 such that liquid
discharged from the pump 110 travels around the electric motor 108
and into the discharge pipe 126 to be discharged upwardly out of
the tank 10. Typically, such a motor will include a cooling passage
allowing some of the pumped liquid to be passed along the motor for
cooling purposes, as is well known in the art.
[0086] At the point in the installation of the assembly 100
illustrated in FIG. 5, the discharge pipe 126 can be secured to the
insertion tube 124 with a retainer member 128. In the illustrated
embodiment, the discharge pipe 126 includes an upper flange 130
with appropriate bolt holes for receiving bolts 132 for connection
to the retaining plate 128. Additional holes on the retainer 128
are connected to an upper flange of the adapter 122 and an upper
flange of the insertion tube 124, described in greater detail
below. As such, the assembly 100 can be inserted into the valve 54
and guide tube 52 as a single unit, i.e., the pump 110, motor 108,
insertion tube 124, and discharge pipe 126 being coupled together
as a unit to be inserted into the valve 54 and the guide tube
52.
[0087] The assembly 100 also includes a plurality of seal
assemblies 134 configured to cooperate with the insertion tube 124
to prevent gases from within the vessel 22 from passing upwardly
through the insertion tube 124 between an inner surface of the
insertion tube 124 and an outer surface of the discharge pipe 126,
described in greater detail below.
[0088] The discharge pipe 126 can be provided with a movable seal
136 for preventing gases from passing through the pump 110, through
the discharge pipe 126 into the atmosphere. In the illustrated
embodiment, the movable seal 136 is in the form of a balloon 138
that can be inflated through an inflation conduit 140. In the
illustrated embodiment, the conduit 140 includes a valve 142 for
allowing air to be pumped into the balloon 138, causing the balloon
130 to expand against the inner surfaces of the discharge pipe 126,
thereby forming a seal to prevent gases in the vessel 22 from
passing therethrough. In the illustrated environment of a liquid
natural gas vessel, the pressures within the tank 10 are relatively
low, i.e., 1 to 2 pounds per square inch. Thus, the balloon 138 can
be sized and configured to provide sufficient anchoring force
against such a pressure while disposed within the discharge pipe
126.
[0089] With reference to FIGS. 6-9, the adapter 122 is described in
greater detail. In the illustrated embodiment, the adapter 122
includes a pipe section 150, an upper flange 152, and a lower
flange 154. The pipe section 150 can be formed from standard pipe
having an inner diameter approximately equal to the inner diameter
of the valve 54. With reference to FIG. 9, the inner surface 156 of
the adapter 122 is configured to provide a seal with an outer
surface of the insertion tube 124 (FIG. 5). As such, the adapter
122 and the insertion tube 124 cooperate to prevent gas within the
vessel 22 from passing upwardly between the outer surface of the
insertion tube 124 and the inner surface 156 of the adapter
122.
[0090] In the illustrated embodiment, the adapter 122 includes an
upper O-ring groove 158 and a lower O-ring groove 160. However,
this is merely one type of sealing structure that can be provided
on the inner surface 156 of the adapter 122. Other types of seals
can also be used. Where the upper and lower O-ring grooves 158, 160
are used to form a seal with the outer surface of the insertion
tube 124, the O-ring grooves 158, 160 and the O-rings used
therewith are chosen based on the environment of use, as is well
known in the art. As noted above, the pressure within the vessel 22
can be quite low in certain environments, such as the typical
pressure used in liquid natural gas containers of about 1 to 2 psi.
In some embodiments, a single O-ring groove can be used.
[0091] A further advantage is provided where the adapter 122 is
configured to allow the assembly 100 to be flushed. For example,
the adapter 122 can be configured to allow a non-reactive gas to be
circulated within at least a portion of the assembly 100 to ensure
that any leak of a gas from the vessel 22 is diluted as quickly as
possible as it travels up through the assembly 100.
[0092] In the illustrated embodiment, the adapter 122 includes an
inlet 162 and an outlet 164. The inlet and outlet 162, 164 can be
connected to an inert gas circulation system (not shown). Such a
circulation system can be used to circulate an inert gas, such as,
for example, but without limitation, nitrogen gas, into the space
between the inner surface of the insertion tube 124 and the outer
surface of the discharge pipe 126. For example, as shown in FIG. 5,
an inert gas IG flows into the adapter 122 through the inlet 162,
circulates within a space between the inner surface of the
insertion tube 124 and an outer surface of the discharge pipe 126,
and is then discharged through the outlet 164 of the adapter 122.
As such, by filling the space between the outer surface of the
discharge pipe 126, the inner surface of the insertion tube 124,
and the space above the upper-most seal 134, any natural gas that
may leak into the space is immediately diluted with the inert gas,
thereby reducing the ignition potential of said gas as quickly as
possible.
[0093] With reference again to FIGS. 6-9, the adapter 122 also
includes a plurality of bolt holes 166 on the upper flange 152 and
a plurality of bolt holes 168 on the lower flange 154. The bolt
holes 166, 168 are configured to provide a means for attaching the
adapter 122 to the valve 54 as well as other devices, including the
insertion tube 124 and the retainer 128.
[0094] With reference to FIG. 10, the insertion tube 124 includes a
pipe section 170 and a mounting flange section 172. The pipe
section 170 can be formed from any type of material suitable for
the environment in which it is used. In the illustrated embodiment,
the insertion tube 124 is used in a liquid natural gas environment.
Thus, the material of the insertion tube 124 should be appropriate
for a cryogenic environment, which can be as cold as -260.degree.
F. Thus, for example, the pipe section 170 can be made from
stainless steel or aluminum, or numerous other materials as is well
known in the art.
[0095] In order to provide the desired seal with the inner surface
156 of the adapter 122, and the O-rings provided in the grooves
158, 160, the outer surface of the pipe section 170 should be
polished as smooth as practicable.
[0096] With reference to FIGS. 12-14, sectional views of the
insertion tube 124 are illustrated therein. As shown in FIGS. 11
and 14, a lower end 172 of the pipe section 170 includes a tapered
area 174. The tapered portion 174 comprises an area of reducing
thickness along an inner surface 176 of the insertion tube 124.
This provides an additional advantage when removing the discharge
pipe 126 from the insertion tube 124.
[0097] With reference again to FIG. 11, at an upper end 178 of the
pipe section 170, an aperture 180 is disposed for allowing
circulation of an inert gas as described above with reference to
FIG. 5.
[0098] With reference to FIGS. 15 and 16, the flange portion 172 of
the insertion tube 124 includes a central aperture 180 in a
plurality of bolt holes 182. The upper end 178 of the pipe section
170 can be connected to the aperture 180 through any appropriate
means. For example, the upper end 178 can be connected to the
aperture 180 with an interference fit. Alternatively, or in
addition, the upper end 178 can be connected to the aperture 180
through bonding, welding, adhesives, and the like. The bolt holes
182 are configured to be aligned with the bolt holes 166 of the
upper flange 152 of the adapter 122. Additionally, a lower facing
surface of the flange 172, i.e., the surface of the flange 172 that
abuts against the flange 152, can include a seal, e.g., a gasket,
for creating a seal against the flange 152.
[0099] As noted above with reference to FIG. 5, the assembly 100
includes seals 134 for defining seals between the outer surface of
the discharge pipe 126 and the inner surface of the insertion tube
124. As shown in FIG. 20, the seals 134, in the illustrated
embodiment, comprise a disk member 190, having a central aperture
192, and an outer circumferential edge 194 that is configured to
define a seal with the inner surface 176 of the insertion tube 124.
In the illustrated embodiment, the outer peripheral edge 194
includes an O-ring groove 196 configured to cooperate with an
O-ring (not shown) for forming an appropriate seal against the
inner surface 176 of the insertion tube 124 with sufficient sealing
strength to prevent the subject gas from leaking there-past.
[0100] The central aperture 192 is configured to form a sealing
engagement with the outer surface of the discharge pipe 126. In the
illustrated embodiment, the central aperture 192 can be sized to
form an interference fit with the outer surface of the discharge
pipe 126. Alternatively, the central aperture 192 can be provided
with a clearance with the outer surface of the discharge pipe 126
and then welded thereto with a continuous weld so as to form a gas
tight seal.
[0101] A further advantage is provided where the disk member 190
includes an accessory aperture 198. In the illustrated embodiment,
the aperture 198 is sized to allow an electrical conduit to pass
therethrough. In the illustrated embodiment, the aperture 198 is
configured to allow the electrical conduit 112 to pass therethrough
(See FIG. 5). Optionally, the aperture 198 can be further sized to
accept a sealing grommet for providing a seal between the inner
surface of the aperture 198 and the outer surface of the conduit
112. For example, as shown in FIG. 5, grommets 200 are illustrated
as extending through the seals 134. These grommets 200 extend
through the apertures 198 illustrated in FIGS. 17 and 20 so as to
provide a seal between the inner surface of the aperture 198 and
the outer surface of the conduit 112.
[0102] With reference to FIG. 20A, an initial operation for
installing the assembly 100 onto the tank 10 is illustrated
therein. As shown in FIG. 20A, the valve 54 is closed such that the
valve member 120 is in the deployed position and extends into the
interior of the valve 54. Additionally, the adapter 122 is bolted
to the upper end of the valve 54. A lower end of the assembly 100
is illustrated as extending through the adapter 122 such that the
outer surface of the pipe section 170 of the insertion tube 124
contacts O-rings 210, 212 disposed in the O-ring grooves 158, 160
of the adapter 122. Thus, the outer surface of the pipe section 170
is sealed to the inner surface 156 of the adapter 122.
[0103] With reference to FIG. 5, although the assembly 100 is
illustrated in a different position, it is to be noted that the
seals 134 maintain a seal between the outer surface of the
discharge pipe 126 and the inner surface 176 of the insertion tube
124. Finally, it is to be noted that the balloon 138 is disposed
within the interior of the discharge pipe 126. With the assembly
100 positioned as such, the valve member 120 can be withdrawn from
the valve 54, thereby opening the valve 54 to the interior of the
vessel 122. With the valve 54 open, the assembly 100 can be slid
downwardly into the guide tube 52 until it reaches the position
illustrated in FIG. 5.
[0104] As noted above with reference to FIG. 11, the aperture 180
in the pipe section 170 is disposed at the upper end 178 of the
insertion tube 124. Thus, with the assembly 100 in the position
illustrated in FIG. 5, the inert gas IG can be injected into the
inlet 162 and then be circulated within the space above the
uppermost seal 134 and between the outer surface of the discharge
pipe 126 and the inner surface 176 of the insertion tube 124. After
any circulation of inert gas is performed, the retainer 128 can be
removed. For example, with reference to FIG. 21, the retainer 128
has been removed and the discharge pipe 126 has been pulled
upwardly from the insertion tube 124. Another retainer 230 is
illustrated as supporting the discharge pipe 126 against the
mounting flange 172 of the insertion tube 124.
[0105] As such, the retainer 230 supports the weight of the
discharge pipe 126, the electric motor 108, and the pump 110. Thus,
an additional discharge pipe 126A can be connected to the upper end
of the discharge pipe 126. Prior to connecting the additional
discharge pipe 126A to the discharge pipe 126, the air filling tube
140 can be threaded through the discharge pipe 126A. After
connecting the discharge pipe 126A, the retainer 230 can be removed
and the two discharge pipes 126, 126A can be lowered down into the
vessel 22. During or after the discharge pipes 126, 126A have been
lowered further into the insertion tube 124, the balloon 138 can be
moved upwardly through the discharge pipe 126A. For example, the
balloon 138 can be partially deflated by releasing some of the air
from within the balloon through the valve 142. Once the balloon 138
is dislodged, the balloon 138 can be slid upwardly through the
discharge pipe 126A until it reaches a position near the upper end
thereof. At that point, additional air can be reinserted into the
balloon 138 to secure its position and continue to provide a seal
against the outflow of gas from the vessel 22.
[0106] Additionally, as the discharge pipes 126, 126A are lowered
into the insertion tube 124, the inert gas IG can continuously be
circulated within the spaces between the seals 134 and the outer
surface of the discharge pipes 126, 126A and the inner surface 176
of the insertion tube. As such, the atmospheric air that initially
is drawn into the insertion tube 124 as the discharge pipes 126,
126A are lowered into the tube 124, is continuously diluted. Of
course, if desired, the discharge pipes 126, 126A can be stopped at
various positions wherein the seals 134 define discrete chambers
within the insertion tube 124 such that these discrete chambers are
in communication with the inlet and outlet 162, 164 so as to
completely dilute and refill these chambers with an inert gas. As
such, the inert gas prevents any air fuel mixtures forming where
the gas within the vessel 22 is a potential fuel.
[0107] It is to be noted also that the conduit 112 can be made from
a single piece of conduit and continuously thread through the seals
134 and grommets 200 as additional discharge pipe sections 126,
126A are connected together. With reference to FIGS. 22-25,
exemplary discharge pipes 126, 126A are illustrated therein.
[0108] As shown in FIG. 22, the discharge pipes 126, 126A can
comprise a commercially available one and half-inch (1{fraction
(1/2)}") pipe 240. Of course, the type of pipe 240 used can be
changed in accordance with the environment of use, as is well known
in the art.
[0109] The discharge pipes 126, 126A also include mounting flanges
242 at both the upper and lower ends thereof. The mounting flanges
242 can comprise commercially available flanges for standard
piping.
[0110] With reference to FIG. 23, each of the flanges 242 include a
notch 244 for allowing the electrical conduit 112 to extend
thereby. Additionally, each of the flanges 242 include apertures
246 for receiving bolts for connecting the flanges 242 to the
flanges 242 of adjacent discharge pipes 126, 126A.
[0111] FIGS. 24 and 25 illustrate a shorter discharge pipe 126,
126A which may be used in conjunction with the longer discharge
pipes 126, 126A illustrated in FIG. 22. This provides greater
flexibility in installing the assembly 100 into the tank 10. For
example, the discharge pipes 126, 126A illustrated in FIG. 22 can
be a standard length, for example, but without limitation, 10 feet
long. Thus, if it is desired to reach a depth into the tank 10 that
is not a multiple of 10 feet, another size discharge pipe 126, 126A
can be used to reach the final depth.
[0112] Optionally, the flanges 242 can be provided with seals
similar to that of the seals 134. As such, the assembly 100
provides further sealing against the leaking of gas from the vessel
22 to the atmosphere.
[0113] With reference to FIG. 26, as the final depth is approached,
a final discharge pipe assembly 300 can be connected to the top of
the previously installed discharge pipe 126A. As shown in FIG. 26,
a lower end of the final discharge pipe 300 includes a standard
flange 242 which can be identical to the uppermost flange 242 of
the discharge pipe 126A. Thus, a further description of the
connection therebetween is not described further.
[0114] At its upper end, the final discharge pipe 300 can include a
headplate 302 which is configured to form a complete seal over the
upper flange 156 of the adapter 122. The headplate 302 can include
a gland nut assembly 304 for sealing the outer surface of the final
discharge pipe assembly 300 against an aperture formed in the
headplate 302. As such, the final depth of the pump 110 within the
tank 10 can be adjusted on site. Then, once the final depth is
reached, the gland nut assembly 304 can be tightened to thereby
provide a gas tight seal at the upper end of the adapter 122.
[0115] The upper end of the final discharge pipe 300 also includes
a valve 306. The valve 306 can be configured to allow the balloon
138 to pass therethrough after the final discharge pipe 300 has
been secured to the headplate 302. Thus, with the valve 306 open,
the balloon 138 can be pulled to the position illustrated in FIG.
26 in a slightly deflated state. After the balloon has reached the
position illustrated in FIG. 26, the valve 306 can be closed and
the balloon 138 can be removed. As such, the balloon 138 can be
used to maintain a seal of the discharge pipe assemblies during the
installation process.
[0116] FIGS. 27 and 28 illustrate the final discharge pipe assembly
300 in greater detail.
[0117] With reference to FIG. 29, a further advantage is provided
where each discharge pipe assembly 126 is provided with a valve 310
that can replace the balloon 138. For example, as shown in FIG. 29,
the discharge pipe 126' includes a valve 310. The valve 310 can be
any type of valve to be installed in-line along the pipe forming
the discharge pipe 126'. At the stage of installation illustrated
in FIG. 29, which corresponds generally to the position illustrated
in FIG. 5, the valve 310 is closed. Thus, no gas from the vessel 22
can escape.
[0118] With reference to FIG. 30, after the retainer 128 has been
removed and the retainer 230 has been installed, the discharge pipe
126A' can be connected to the upper end of the discharge pipe 126'.
At this point, the valve 310A of the discharge pipe 126A' is
closed. Thus, the valve 310 on the discharge pipe 126' can be
opened. As such, the valve 310A maintains the seal within the
discharge pipe to prevent the discharge of any fluids from the tank
10. As such, the valves 310, 310A provide further protection
against leaks of fluid from the vessel 22. For example, it is known
that a balloon such as the balloon 138 can be operated improperly
and thus, due to human error, can be allowed to slip out. However,
if one of the valves 310, 310A are accidentally left open, they can
simply be closed.
[0119] With reference to FIGS. 31-34, further detail of the
discharge pipes 126', 126A' are illustrated therein. However, no
further description of FIGS. 31-34 are necessary for one of
ordinary skill in the art to make and use the inventions disclosed
herein.
[0120] FIG. 35 illustrates a final discharge pipe 300' installed in
the assembly 100. The final discharge pipe 300' can be constructed
in accordance with the description of the final discharge pipe 300
illustrated in FIGS. 26-28. Thus, no further description of the
discharge pipe 300' is necessary for one of ordinary skill in the
art to make and use the inventions disclosed herein.
[0121] A further advantage can be achieved by including an
"expansion joint" section in the discharge pipe 126 above the
electric motor 108. A schematic illustration of an expansion joint
in FIG. 35A is identified generally by the reference numeral 312.
Such expansion joints are commercially available for non-cryogenic
uses. However, because this joint will be placed inside the tank 10
during use, the joint 312 can leak during use. Of course, it is
preferable that such an expansion joint be optimized so as not to
leak during use. Preferably, the expansion joint 312 will allow the
discharge pipe 126' to expand enough so that the pump 110 remains
on the lower surface 26 of the vessel 22. In the illustrated
embodiment, the dome 18 can rise about one foot due to the thermal
expansion of the outer walls 14 caused by the change of night to
day when sunlight strikes, and thereby expands, the walls 14. As
such, the adapter 122 rises by the same amount, thereby causing the
pump 110 to move away from the bottom 26 of the vessel 22.
[0122] Thus, in the illustrated embodiment, the expansion joint 312
can allow the pipe 126' to expand about one foot, thereby allowing
the pump 110 to remain as close to the bottom 26 as possible.
[0123] FIG. 36 illustrates another embodiment of an expansion joint
unit 312, identified generally by the reference numeral 312'. The
expansion joint unit 312' preferably comprises a pipe member 320
sized to receive a fixed connector 330 and a movable connector 340
therein. In this embodiment, the movable connector 340 is sized to
slidingly move within the pipe member 320. In FIG. 36, the arrow E
identifies the extension direction and the arrow R identifies the
retracting direction of the expansion joint unit 312'.
[0124] The movable connector 340 is preferably fastened to a
support member 350 and houses a seal 360 therebetween, as is
further described below. Additionally, a retaining member 365 is
preferably disposed on the pipe member 320 to substantially limit
the motion of the movable member 340. FIG. 36 illustrates the fully
extended position of the expansion joint 312'. In the fully
extended position, the moveable connector 340 abuts against the
retainer member 365. In the fully retracted position, the moveable
connector 340 abuts against the fixed connector 330. An
intermediate position of the moveable connector 340 (in phantom
line) is also illustrated in FIG. 36.
[0125] In some embodiments, the retaining member 365 can comprise a
snap ring. However, in other embodiments, the retaining member 365
can be any structure configured to substantially limit the motion
of the movable member 340, such as a detent or protrusion on the
pipe member 320.
[0126] A further advantage is provided where the expansion joint
unit 312' comprises an anti-rotation device 370 configured to
prevent rotation of the lower end of the assembly relative to the
upper portion of the assembly 100. For example, the pump 110 can
include a shaft rotating about a vertical axis. Thus, the pump 110
can generate a torque, tending to cause the lower end of the
discharge pips 126' to rotate relative to the upper end of the
discharge pipe 126'. If this rotation occurs, the conduit 112 would
be the only structure that could resist such a rotating motion,
thereby imparting an undesirable stress on the conduit 112. Thus,
by including an anti-rotation device in the expansion joint 312',
such undesirable stresses can be avoided.
[0127] In some embodiments, the anti rotation device 370 can be
fastened to the fixed connector 330 via fasteners 380. In the
illustrated embodiment, the fasteners 380 consist of bolts.
However, in other embodiments, the anti-rotation device 370 can be
fastened to the fixed connector 330 using other fastening
mechanisms, such as screws, adhesives, or welds. In still another
embodiment, the fixed connector 330 and anti-rotation device 370
and be an integral unit.
[0128] In the illustrated embodiment, a fixation member 390 is
disposed between at least a portion of the fixed connector 330 and
the pipe member 320, as discussed further below. The fixation
member 390 preferably maintains the fixed connector 330 in a
substantially fixed position relative to the pipe member 320. In
the illustrated embodiment, the fixation member 390 consists of at
least one set screw. In other embodiments, the fixation member 390
can be a weld disposed between the fixed connector 330 and the pipe
member 320. In another embodiment, the fixation member 390 can be
an adhesive disposed between the fixed connector 330 and the pipe
member 320. In still another embodiment, the fixed connector 330
can be connected to the pipe member 320 via a press-fit
connection.
[0129] With reference to FIGS. 37A-E, the pipe member 320 and fixed
connector 330 of the expansion joint unit 312 are illustrated in
greater detail. As shown in FIG. 37A, the pipe member 320 has a
length L1 that extends between a proximal end 320a and a distal end
320b of the pipe member 320.
[0130] The proximal end 320a preferably connects to the movable
connector 340, as shown in FIG. 36. Similarly, the distal end 320b
preferably connects to the fixed connector 330.
[0131] With reference to FIGS. 37A-D, the pipe member 320 defines
an inner surface 320c that preferably extends circumferentially
about an axis X1 of the pipe member 320 at a diameter 320d. In the
illustrated embodiment, the inner surface 320c is preferably a
cylindrical surface, with a circular cross-section. However, in
other embodiments the inner surface 320c can have other
cross-sectional shapes, such as square or polygonal, with a
corresponding effective diameter 320d.
[0132] As shown in FIGS. 37C and 37D, the pipe member 320
preferably comprises a slot 322 on the inner surface 320c and
disposed substantially at the proximal end 320a of the pipe member
320. The slot 322 preferably receives the retaining member 365
therein. In one embodiment, the slot 322 lockingly engages the
retaining member 365. Preferably, the slot 322 extends
substantially continuously along the inner surface 320c of the pipe
member 320. In another embodiment, the slot 322 can consist of a
number of discreet slots 322 disposed along the inner surface 320c
of the pipe member 320.
[0133] As shown in FIG. 37A, the inner surface 320c of the pipe
member 320 also defines a recess 324 having a diameter 324a at the
distal end 320b of the pipe member 320. Preferably, the diameter
324a of the recess 324 is greater than the diameter 320d of the
inner surface 320c. In the illustrated embodiment, the recess 324
extends substantially continuously about the circumference of the
inner surface 320c. In another embodiment, the recess 324 consists
of discreet recesses 324 disposed about the circumference of the
inner surface 320c.
[0134] With reference to FIG. 37B, the fixed connector 330 extends
from a proximal end 330a to a distal end 330b, and has inner and
outer surfaces 332. 334. In the illustrated embodiment, at least a
portion of the inner surface 332 has a first diameter 332a, and at
least second portion of the inner surface 332 has a second diameter
332b. Preferably, the second diameter 332b is greater than the
first diameter 332a, so as to define a retaining surface 332c on
the inner surface 332.
[0135] Likewise, at least a portion of the outer surface 334 has a
first diameter 334a, at least a second portion of the outer surface
334 has a second diameter 334b, and at least a third portion of the
outer surface 334 has a third diameter 334c. Preferably, the first
diameter 334a is greater than the second diameter 334b, so as to
define a first retaining surface 335a, and the second diameter 334b
is greater than the third diameter 334c, so as to define a second
retaining surface 335b. In another embodiment, the diameters 334a,
334b, 334c can have substantially the same dimension. In still
another embodiment, at least two of the diameters 334a, 334b, 334c
can have the same dimension.
[0136] In the illustrated embodiment, the inner surface 332 defines
a passage 336 through the fixed connector 330. Preferably, the
passage 336 consists of a proximal section 336a and a distal
section 336b. In one embodiment, the first diameter 332a of the
inner surface 332 defines the proximal section 336a. Likewise, the
second diameter 332b of the inner surface 332 defines the distal
section 336b. Additionally, at least one fastener opening 338 is
formed on the proximal end 330a of the fixed connector 330. The
fastener openings 338 preferably receive the fasteners 380 therein,
as discussed above and shown in FIG. 36. For example, in one
embodiment the fastener openings 338 can have a threaded surface
that engages a corresponding thread on the fasteners 380.
[0137] As illustrated in FIG. 37C, the first diameter 334a of the
outer surface 334 is preferably about the same dimension as the
inner diameter 320d of the pipe member 320. In one embodiment, the
first diameter 334a can be slightly larger than the inner diameter
320d of the pipe member 320 so that the fixed connector 330 and
pipe member 320 are joined via a press-fit connection. In another
embodiment, the first diameter 334a is smaller than the inner
diameter 320d of the pipe member 320. With the fixed connector 330
disposed in the pipe member 320, at least one of the portions of
the outer surface 334 having second and third diameters 334b, 334c
defines a slot 326 between the pipe member 320 and the fixed
connector 330, as shown in FIG. 37C. The slot 326 preferably
receives the fixation member 390, as discussed above. In a
preferred embodiment, the slot 326 extends substantially
continuously about the circumference of the fixed connector 330. In
another embodiment, the slot 326 consists of a number of discreet
slots 326 disposed circumferentially about the outer surface 334
and between the fixed connector 330 and the pipe member 320.
[0138] In the illustrated embodiment, as shown in FIGS. 37B and C,
the distal section 336b of the passage 336 preferably receives at
least a portion of the pump assembly 106 therein. In one
embodiment, said portion of the pump assembly 106 extends into the
distal section 336b so as to contact the retaining surface 332c. In
another embodiment, the portion of the inner surface 332 having
second diameter 332b can be threaded to engage a corresponding
threaded surface on the pump assembly 106. In still another
embodiment, said portion of the pump assembly 106 can be press-fit
to the distal section 336b of the passage 336. In yet another
embodiment, the pump assembly 106 can be welded to the distal
section 336b of the passage 336.
[0139] As shown in FIGS. 37E, the inner and outer surfaces 332, 334
of the fixed connector 330 are preferably circular. However, in
other embodiments the inner and outer surfaces 332, 334 can have
other shapes, such as square and polygonal. Preferably, the outer
surface 334 has the same shape as the inner surface 320d of the
pipe member 320. Similarly, the inner surface 332 that defines the
distal section 336b of the passage 336 preferably has the same
shape as the portion of the pump assembly 106 that is inserted
therein.
[0140] FIGS. 38A-E further illustrate the movable connector 340 of
the expansion joint unit 312. As illustrated in FIG. 38A, the
movable connector 340 extends between a proximal end 340a and a
distal end 340b and preferably comprises a base 342 at the distal
end 340b. In the illustrated embodiment, the base 342 defines at
least one fastener opening 342a and a primary opening 342b, wherein
the openings 342a, 32b extend through the base. Each fastener
opening 342a preferably receives a fastener 400 therethrough (see
FIG. 38C). As shown in FIG. 38C, the fastener 400 can be a threaded
anchor. However, in other embodiments, the fasteners 400 can be
dowels, bolts, screws, adhesives, welds, brackets, braces or any
other fastening mechanisms suitable for use in a cryogenic
environment.
[0141] Likewise, the primary opening 342b preferably slidingly
receives the anti-rotation device 370 therethrough. As shown in
FIG. 38E, the base 342 preferably has at least one slot 342c formed
therein that extends outward from the primary opening 342b. Said
slots 342c preferably receive the anti-rotation device 370
therethrough, as further discussed below.
[0142] As best illustrated in FIG. 38D, the base 342 also
preferably has a chamfer 342d at the distal end 340b of the movable
connector 340 that is oriented at an angle .alpha. relative to the
base 342. The chamfer 342d can be at any angle.
[0143] With reference to FIG. 38A, the movable connector 340 also
preferably comprises a circumferential wall 344 that extends from
the base 342 to a free end at the proximal end 340a of the movable
connector 340. The wall 344 has an inner surface 344a with an inner
diameter 344b, and an outer surface 346 with an outer diameter
346a. The inner surface 344a and the base 342 define a cavity 347
therebetween.
[0144] In the illustrated embodiment, at least one protrusion 348
having a width 348a extends outward from the outer surface 346 of
the wall 344 to an outer diameter 348b. In one preferred
embodiment, the protrusion 348 extends substantially continuously
about the circumference of the outer surface 346 and the width 348a
extends radially outward from the outer surface 346 of the wall
344. In another embodiment, the protrusion 348 consists of a number
of discrete protrusions 348 that extends radially outward from the
outer surface 346 of the wall 344. Preferably, the outer diameter
348b of the protrusion 348 is smaller than the inner diameter 320d
of the pipe member 320, so that the movable connector 340 can
slidably move within the pipe member 320.
[0145] In some embodiments, the cavity 347 receives one end of the
discharge pipe 126' therein. The inner diameter 344b of the wall
344 is generally about the same dimension as the outer diameter of
the discharge pipe 126'. In another embodiment, the inner diameter
344b of the wall 344 can be slightly smaller than the outer
diameter of the discharge pipe 126' to join the movable connector
340 and the discharge pipe 126' via a press-fit connection. In
still another embodiment, the inner surface 344a can be threaded to
engage a corresponding thread on the outer surface of the discharge
pipe 126'. In yet another embodiment, the inner surface 344a of the
movable connector 340 can be welded to the outer surface of the
discharge pipe 126'. In still other embodiments, the movable
connector 340 can be fastened to the discharge pipe 126' via other
fastening mechanisms, such as bolts, screws, adhesives, brackets
and braces.
[0146] FIG. 38B illustrates a support member 350 that is preferably
fastened to the base 342 of the movable connector 340. In another
embodiment, the support member 350 and movable connector 340 can be
manufactured as an integral unit. The support member 350 has a
diameter 352 that is preferably smaller than the inner diameter
320d of the pipe member 320, so that the support member 350
slidably moves within the pipe member 320. In the illustrated
embodiment, the support member 350 has a diameter 352 of
approximately the same dimension as the outer diameter 348b of the
protrusion 348. However, in other embodiments, the support member
350 can have a diameter 352 smaller or larger than the diameter
348b of the protrusion 348.
[0147] The support member 350 comprises a number of fastener
openings 354 therethrough, wherein each opening 354 can be aligned
with the corresponding fastener opening 342a in the base 342 of the
movable connector 340. The support member 350 also comprises a
primary opening 356 that preferably aligns with primary opening
342b in the base 342 of the movable connector 340 when the movable
connector 340 and the support member 350 are adjacent each other.
The support member 350 also preferably comprises at least one slot
358 formed therein and extending outward from the primary opening
356, wherein said primary opening 356 and slots 358 slidingly
receive the anti-rotation device 370 therethrough.
[0148] FIG. 38C illustrates an assembly of the movable connector
340 and support member 350. In the illustrated embodiment, the
fasteners 400 extend through the fastener openings 342a, 354 to
connect the movable connector 340 and support member 350 together.
Though the illustrated embodiment shows the fasteners 400 as
threaded inserts, the fasteners 396 can comprise other fastening
mechanisms, as discussed above.
[0149] With further reference to FIG. 38C, the protrusion 348
defines a space 359 between the support member 350 and movable
connector 340. In a preferred embodiment, the sealing member 360 is
disposed in the space 359, as shown in FIG. 36. In one embodiment,
the seal 360 comprises Teflon rope. However, in other embodiments,
the seal 360 can be made of other materials suitable for used in
cryogenic environments. Preferably, the seal 360 substantially
prevents the leakage of fluid through the space 359 between the
support member 350 and the protrusion 348 of the movable connector
340.
[0150] FIG. 38D shows an enlarged view of a section of the base 342
of the movable connector 340. Preferably, the chamfer 342d defines
a slot 349 between the base 342 and the support member 350 when the
support member 350 is adjacent the movable connector 340. In a
preferred embodiment, the slot 349 receives a seal disposed between
the movable connector 340 and the support member 350. In another
embodiment, the slot 349 can receive a weld therein to fasten the
support member 350 to the movable connector 340 and substantially
prevent leakage of fluid through the slot 349.
[0151] FIG. 38E shows a top view of the support member 350 and
movable connector 340 assembly. In the illustrated embodiment, the
slots 342c disposed along the periphery of the primary opening 342b
of the movable connector 340 and the slots 358 disposed around the
periphery of the primary opening 356 of the support member 350, are
substantially aligned with each other. The slots 342c, 358
preferably receive at least a portion of the anti-rotation device
370 therethrough. Although the illustrated embodiment shows four
slots 342c, 358 in the primary openings 342b, 356 of the movable
connector 340 and support member 350, respectively, the number of
slots 342c, 358 can be fewer or greater.
[0152] FIG. 37E also illustrates the position of the fastener
openings 342a, 354 in the movable connector 340 and support member
350. Although four fastener openings 342a, 354 are shown, the
movable connector 340 and support member 350 can have fewer or more
fastener openings 342a, 354.
[0153] FIGS. 39A-F further illustrate one embodiment of an
anti-rotation device. In the illustrated embodiment, the
anti-rotation device 370 comprises an elongated beam member 372
that extend between a proximal end 372a and a distal end 372b and
defines a length L2 therebetween. Preferably, the beam member 372
extends about an axis X2.
[0154] As shown in FIG. 39D, in the illustrated embodiment the beam
member 372 has a cross-section generally in the shape of a cross
extending from a center 372c to ends 372d. Preferably, the ends
372d are sized to slidably move within the slots 342c, 358 of the
movable connector 340 and support member 350. Additionally, the
ends 372d are preferably sized to have an effective diameter 372e
that is lower than the inner diameter of the discharge pipe 126'.
However, the beam member 372 can have other cross-sectional shapes,
such as square, triangular, or polygonal.
[0155] With reference to FIGS. 39B, and E-F, the anti-rotation
device 370 also preferably comprises a base 374 with a diameter
374a that connects to the distal end 372b of the beam member 372.
In the illustrated embodiment, the base 374 connects to the beam
member 372 via a weld. In other embodiments, the base 374 can be
connected to the beam member 372 with other fastening mechanisms,
such as adhesives, bolts, screws, brackets or braces. In still
another embodiment, the base 374 and beam member 372 can be an
integral unit.
[0156] The diameter 374a of the base 374 preferably has
approximately the same size as the first diameter 334a of the outer
surface 334 of the fixed connector 330. In another embodiment, the
diameter 374a of the base 374 can be lower than the first diameter
334a of the fixed connector 330. In another embodiment, the
diameter 374a of the base 374 can be greater than the first
diameter 334a of the fixed connector 330. Additionally, the
diameter 374a of the base 334 is preferably approximately the same
size as the inner diameter 320d of the pipe member 320.
[0157] The base 374 preferably defines a number of primary openings
374b disposed about a center 374c of the base 374 on either side of
arms 374d of the base 374. In a preferred embodiment, the arms 374d
of the base 374 support the ends 372d of the beam member 372 and
the center 372c of the beam member 372 generally aligns with the
center 374c of the base 374. Though the illustrated embodiment
shows four primary openings 374b having a generally triangular
shape, the base 374 can have more or fewer primary openings 374b
having other shapes suitable for allowing fluid flow
therethrough.
[0158] The base 374 also preferably defines fastener openings 374e
disposed circumferentially along the base 374 and sized to receive
the fasteners 380 as discussed above. The fastener openings 374e
preferably align with corresponding fastener openings 338 on the
fixed connector 330 of the expansion joint unit 312, as illustrated
in FIGS. 36, and 37B, E. Though the illustrated embodiment shows
four fastener openings 374c, the base 374 can have more or fewer
fastener openings 374e.
[0159] The expansion joint unit 312 is preferably made of materials
suitable for use in cryogenic environments. For example, in one
embodiment, the expansion joint unit 312 can be made of stainless
steel. In another embodiment, the expansion joint unit 312 can be
made of aluminum. In other embodiments, the expansion joint unit
312 can be made of high strength materials appropriate for a
cryogenic environment.
[0160] During use, the expansion joint unit 312 can better maintain
the pump 110 in contact or in close proximity with the lower
surface 26 of the vessel 22. For example, during operation, the
expansion joint unit 312 is preferably fastened to the discharge
member 126' and to the pump assembly 106, as described above. The
discharge member 126', expansion joint unit 312, and pump assembly
106 are then lowered into the vessel 22 until the pump 110
substantially contacts the lower surface 26 of the vessel 22.
[0161] Preferably, the discharge member 126' is further lowered so
that the movable connector 340, to which the discharge member 126'
is attached, movably slides within the pipe member 320 of the
expansion joint unit 312, and so the beam member 372 of the
anti-rotation device 370 extends into the discharge member
126'.
[0162] In a preferred embodiment, the discharge member 126' is
lowered about one foot into the pipe member 320 of the expansion
joint unit 312. In another embodiment, the discharge member 126'
can be lowered less than one foot into the pipe member 320 of the
expansion joint unit 312. In still another embodiment, the
discharge member 126' can be lowered less than one foot into the
pipe member 320 of the expansion joint unit 312. In yet another
embodiment, the discharge member 126' can be lowered into the pipe
member 320 of the expansion joint unit 312 by at least an amount
corresponding to the expected rise of the dome 18 of the vessel 22
due to thermal expansion. Accordingly, as the dome 18 of the vessel
22 rises due to thermal expansion, as discussed above, said
expansion also causes the discharge pipe 126' to withdraw from the
expansion joint unit 312. However, in a preferred embodiment said
withdrawal of the discharge pipe 126' does not displace the pump
110 from the lower surface 26 of the vessel 22.
[0163] The expansion joint unit 312 preferably also substantially
prevents the rotation of the pump assembly 106 relative to the
discharge pipe 126'. As discussed above, the ends 372d of the beam
member 372 preferably slidably move within the slots 342c, 358 of
the movable connector 340 and support member 350. Accordingly, the
ends 372d and slots 342c, 358 operate as a key and keyway system,
preventing the rotation of the beam member 372 within the pipe
member 320. Accordingly, any rotational force generated by the
electric motor 108 does not cause the rotation of the anti-rotation
device 370 relative to the discharge pipe 126'.
[0164] The expansion joint unit 312 preferably allows the pump 110
to remove RLNG from the vessel 22. The RLNG preferably flows
through the passage 336 of the movable connector 330. The RLNG then
flows through the primary openings 374b of the base 374 of the
anti-rotation device 370. Subsequently, the RLNG passes through the
pipe member 320 and the primary openings 342b, 356 of the movable
connector 340 and support member 350. The RLNG then flows into the
discharge pipe 126' for withdrawal from the vessel 22 as described
above.
[0165] Although the inventions disclosed herein have been disclosed
in the context of certain preferred embodiments and examples, it
will be understood by those skilled in the art that the inventions
disclosed herein extend beyond the specifically disclosed
embodiments to other alternative embodiments and/or uses of the
inventions and obvious modifications and equivalents thereof. Thus,
it is intended that the scope of the inventions disclosed herein
should not be limited by the particular disclosed embodiments
described above, but should be determined only by a fair reading of
the claims that follow.
* * * * *