US3271967A

US3271967A - Fluid handling

Info

Publication number: US3271967A
Application number: US433906A
Authority: US
Inventors: Joseph T Karbosky
Original assignee: Phillips Petroleum Co
Current assignee: Phillips Petroleum Co
Priority date: 1965-02-19
Filing date: 1965-02-19
Publication date: 1966-09-13
Anticipated expiration: 1983-09-13

Description

Sept. 13, L1966 J. T. KARBOSKY FLUID HANDL ING Filed Feb. 19, 1965 United States Patent O 3,271,967 FLUID HANDLING Joseph T. Karbosky, Bartlesville, Okla., assignor to Phillips Petroleum Company, a corporation of Delaware Filed Feb. 19, 1965, Ser. No. 433,906 9 Claims. (Cl. 62-51) This invention relates to a method and apparatus for removing a fluid from a source thereof. In one aspect this invention relates to a method and apparatus for coroling a iiuid, particularly before storage of that fluid.

Although this invention will, for the sake of brevity, be described relative to the treatment, storage and withdrawal of propane it is to be noted that the invention is broadly applicable to fiuids and in particular liquids.

Propane is generally removed from very large storage facilities such as underground Caverns and stored in smaller containers such as metal tanks before being introduced into the necessary transportation means such as tanker ships, railroad cars, pipelines and the like. Heretofore problems have been encountered in the loading of large transportation means such as tanker ships in that large amounts of propane must be supplied in a relatively short time. Here the foremost problems encountered are that the iiow rate from the tank container must be decreased as that tank container is gradually emptied to prevent collapse of the tank due to the reduced pressure therein and that the refrigeration system employed to cool the propane before it is introduced into the tank container is generally of an inadequate capacity to handle the large amount of propane necessary to fill a tanker ship or similar large transportation means.

It has now been found that the rate of withdrawal of propane from a tank container can be maintained substantially constant or even increased notwithstanding high withdrawal rates if propane which is Warmer than that propane present in the tank container is introduced into the tank container when the pressure therein falls below a predetermined minimum value necessary to maintain the desired rate of withdrawal of propane therefrom.

The apparatus necessary for carrying out the above meth-od includes a supply conduit connected to a source of relatively Warm propane and a valved conduit connecting the supply conduit with a tank container from which transportation means are to be loaded. The valve in the valved conduit is operated by a means responsive to pressures prevailing in the tank container.

It has also been found that cooling of the propane prior to introduction of same into the tank lcontainer can be more effectively carried out if that propane is passed in heat exchange relationship through two separate heat exchangers, the first heat exchanger operating at a pressure lower than the pressure of the refrigerant being supplied thereto and the second heat exchanger operating at a pressure lower than the pressure of operation of the first heat exchanger. Thus, relatively warm refrigerant can be passed into the first heat exchange zone and, due to the lower pressure and therefore lower boiling point of the refrigerant in that heat exchange zone, be cooled and be used to cool the propane then passing through that heat exchange Zone. Liquid refrigerant is then removed from the first heat exchange zone and passed into the second heat exchange zone and, due to the lower pressure on the refrigerant in the second heat exchange zone, will be cooled further and therefore cool the propane then passing through that heat exchange zone. Refrigerant vapors from both heat exchange zones are removed, compressed, cooled sufficiently to substantially liquefy same and then returned to the first heat exchange zone.

The apparatus for carrying out the above method in- ICC cludes first and second heat exchangers connected in series and interconnected with a compression and cooling means for forming liquefied refrigerant at elevated pressures. The refrigerant under high pressure is preferably first passed through a receiver to allow for the settling out or other removal of impurities, such as compressor lubricant, prior to introduction of same into the first heat exchanger.

Accordingly, it is an object of this invention to provide a new and improved method and apparatus for removing a fluid from a source thereof. It is another object of this invention to provide a new and improved method and apparatus of cooling a fluid, particularly before that uid is introduced into a storage zone.

Other aspects, objects and advantages of the invention will be readily apparent to those skilled in the art from the description, the drawing, and the appended claims.

In the drawing there is shown diagrammatically a system embodying this invention.

More specifically, there is shown conduit 1 which contains a stream of p-ropane from an underground cavern or similar storage zone which has been treated as desired, e.g. dehydrated, and which must be cooled before being stored in a relatively smaller storage zone such as a tank container. The propane flows through valved conduit 1 into heat exchange relationship with heat exchanger 2 and from heat exchanger 2 through valved conduit 3 into heat exchange relationship with heat exchanger 4. From heat exchanger 4 the now sufciently cooled propane passes through conduit 5 into tank container or storage tank 6. The ow of prop-ane through conduit 5 is controlled by motor valve 7 which in turn is controlled through 8 by pressure controller 9. Pressure controller 9 is responsive through 10 to the pressure in conduit 5 and through 11 and 12 to the pressure in tank 6. Thus, if the pressure in tank 6 should fall below a preset minimum value pressure controller 9 would pinch down valve 7 thereby at least slowing the flow of propane into tank 6 and open valve 16 to allow warm liquid propane to flow therethrough. Under normal conditions a predetermined pressure is maintained in line 5 fby valve 7 and valve 16 is closed.

Propane is removed from tank 6 through conduit 13 by pump 14 and passed to the waiting transportation or other storage means.

When the pressure in tank 6 falls below a preset minimum value due to the rapid removal of propane through conduit 13 and pressure controller 18 opens valve 16 thereby admitting relatively warm propane into tank 6, this relatively warm propane, in substantially liquid form, will flash since it is generally pumped through conduit 1 at a substantially higher temperature than it is stored in tank 6 and at a pressure sufiicient to maintain the propane at in the liquid state at said substantially higher temperature. The flashing of the warm propane increases the pressure in tank 6 and, depending `on the amount of propane introduced through 15, can be used to maintain or increase the rate of withdrawal of propane through conduit 13.

Relatively warm propane from conduit 1 can also pass through conduit 20 into receiver 21. The ow of propane through 20 is controlled by liquid level controller 22 on receiver 21 which through 23 controls motor valve 24. Thus, if the liquid level in receiver 21 should fall below a preset minimum level, liquid level controller 22 will open valve 24 thereby admitting more propane from 20. This propane is used in the refrigeration system for tank 6 and therefore acts as a refrigerant.

Receiver 21 is operated at a relatively high temperature and pressure as compared to the temperatures and pressures in heat exchangers 2 and 4 and the temperature and pressure in tank 6. The warm, high-pressure, refrigerant propane from receiver 21 passes through line 25 into heat exchanger 2. The rate of flow of refrigerant propane through 25 is controlled by liquid level controller 26 which through 27 controls motor valve 28 in a manner similar to that described with refreence to liquid level controller 22. Heat exchanger 2 is maintained at a pressure suflcient to cause the refrigerant propane to boil or vaporize at the desired cooling temperature of that heat exchanger. Thus, some of the refrigerant propane in 25 flashes after passing through valve 28 and the boiling temperature of that propane in heat exchanger 2 is lowered dueto the lower pressure maintained in that heat exchanger. The pressure on the refrigerant propane in heat exchanger 2 is of a magnitude such that the boiling temperature of that propane is lower than the temperature of the propanebeing passed in heat exchange relationship therewith by conduit 1. Since the boiling temperature of the refrigerant propane in heat exchanger 2 is lower than the temperature of the propane in conduit 1 the propane in conduit 1 will be cooled.

Liquid refrigerant propane from heat exchanger 2 is removed by conduit 30 and passed into heat exchanger 4. The rate of flow of refrigerant propane through 30 is controlled by liquid level controller 31 which through 32 controls motor valve 33 in a manner similar to that described with reference to liquid level control 22. Heat exchanger 4 is maintained at an absolute pressure substantially below the pressure maintained in heat exchanger 2, -i.e. no more than 40 percent, preferably from about 10 to about 35 percent, of the absolute pressure in heat exchanger 2.- Thus, liquid refrigerant propane in 30 ilas'hes after passing through valve 33 and the pressure in heat exchanger 4V is such that the -boiling temperature of the liquid refrigerant propane therein is lower than the boiling temperature of the liquid refrigerant propane in heat exchanger 2. Thus, the temperature of the refrigerant propane in heat exchanger 4 is lower than both the temperature of the refrigerant propane in heat exchanger 2 and the temperature of the propane passing from heat exchanger 2 through 3 into heat exchanger 4. Thus, cooled liquid propane passing from heat exchanger 2 through conduit 3 is further cooled by heat exchanger 4 before being passed through S into tank 6.

Refrigerant propane vapors from heat exchanger 4 are removed therefrom by 34 to scrubber 35. In scrubber 35 liquid material, such as compressor oil and liquid propane, is separated from the vapors and removed through valved line 36 to protect

compressors

38 and 44 and for disposition as desired. The vapors are removed from 35 through 37 to compressor 38 which compressor sets the pressure in scrubber 35 and heat exchanger 4. The compressed vapor is passed from compressor 3S through 39 into scrubber 40. Refrigerant propane vapors from heat exchanger 2 which are ata higher pressure than the vapors from heat exchanger 4 pass from heat exchanger 2 through conduit 41 and conduit 39 into scrubber 40. Liquid similar to that found in 35 is separated from the vapors in scrubber 49 and removed therefrom by valved line 42 for disposition as desired. Vapors are removed from scrubber 40 through conduit 43 into compressor 44 wherein they are compressed and then passed by 4SV through heat exchanger 46. In 46 they are substantially completely condensed to the liquid state at their compressed (elevated) pressures. The liquid refrigerant propane discharged from compressor 44 and after condensing in `46 is at a temperature and pressure substantially higher than the liquid refrigerant propane in heat exchanger 2. The compressed and substantially liquefied refrigerant propane passes from heat exchanger 46 through 47 into receiver 21.

Propane vapors, which can contain substantial quantities of lower boiling materials such as ethanes, formed in tank 6 pass therefrom through conduit 5G, desuperheater spray -1 and into conduit 52. Normally, the vapors pass from 52 through conduit 53 into scrubber 54. The vapors can also pass through valved conduit 55. Normally closed motor valve 56 in conduit 55 is controlled through 57 by pressure controller 58 which is responsive through 59 to pressures in tank 6. Thus, if the pressure in tank 6 should exceed a preset maximum value pressure controller 58 will open valve 56 and allow propane vapors to be removed through conduit 55 for a flare or other desired disposition. Liquid removed from the vapors in scrubber 54 pass through valved line 62 into accumulator 63 and from 63 through

valved conduits

64 and 65. The rate of ow of propane through 65 is controlled by motor valve 66 which is controlled through 67 by pressure controller 68 which is responsive through 69 to pressures in conduit 65. A preset pressure is maintained upstream of valve 66. Thus, when the pressure upstream of valve 66 exceeds a preset maximum value pressure controller 68 will further open motor valve 66 thereby allowing more propane to flow therethrough. Propane for the desuperheater spray 51 is supplied from 65 through valved conduit 70.

Propane vapors from scrubber 54 pass through 71 to compressor 72 and from compressor 72 through 73 into heat exchange relationship with heat exchanger 4. The cooled propane then passes from heat exchanger 4 through conduit 74 into cond-uit 65.

Compressed propane discharged from compressor 44 can be returned at least in part through conduit to conduit 81 or conduit 82 or both. The flow of propane from Sil through S1 to 34 is controlled by motor valve 83 which is controlled through 84 by pressure controller 85 and which is responsive through 86 to pressures in conduit 37 and scrubber 35. Thus, if the pressure in conduit 37 drops below a preset minimum value necessary for feeding

compressor

38 or 44 pressure controller 85 will open valve 83 thereby admitting heated propane discharged from compressor 44. If desired, hot propane discharged from compressor 44 can 4be admitted by way of S2 into accumulator 63 and thereby, in effect, pass into tank 6. A similar compressor discharge return system can be employed for compressor 72 between conduits '73 and 53 responsive to pressure variation in tank 6.

Propane vapor from receiver 21 can pass through conduit 90 to 53 and into scrubber 54. The flow of propane through 90 is controlled by motor valve 91 which is controlled through 92 by pressure controller '93 which is responsive through 94 to pressures in receiver 21. Thus, if the pressure in receiver 21 should exceed a preset maximum value pressure controller 93 will open motor valve 91 thereby allowing vapor to pass into 90.

Impurities in the propane in receiver 21 such as oil picked up from

compressors

38 and 44 settle out and are removed from the system by valved conduit 95.

If precleaning of the propane in 25 before introduction of same into heat exchanger 2 is necessary, for example to remove additional oil or other impurities therefrom, a heat exchanger similar to heat exchanger 2 can be employed in conduit 25 whereby refrigerant propane in line 25 is cooled by passing in heat exchange relationship with evaporating liquid refrigerant propane supplied from heat exchanger 4. Oil or other impurities can be removed from the bottomcf this additional heat exchanger and the vapors formed therein can be combined with the vapors flowing in conduit 34 for treatment in scrubber 35 and'compressor 3S. 7

Although the drawing has been described with the use of propane as a refrigerant in heat exchangers 2 and 4, it is to be noted thatra refrigerant separate and distinct from the material ilowing through conduits 1, 3 and 5 and being cooled by heat exchangers 2 and 4 can be employed. It will be apparent that if a separate and distinct refrigerant is employed

conduits

20 and 82 can be omitted if desired. Also, in such a case conduit 9) would be disconnected from 53 and connected to a separate vessel for collection of refrigerant :if an excessive pressure requires the opening of motor valve 91.

Example Commercial propane passes through 1 at 90 F., 225 p.s.i.g. and 182 gallons per minute. Tank 6 is maintained at 50 F. and from 3.5 to 8.5 inches of water pressure. Tank 6 has a capacity of 180,000 barrels of propane and no propane normally passes from 1 through 15 into tank 6. When tank 6 is being used to load a large transportation means such as a tanker ship (which can require a load-ing rate of as much as 5,145 gallons per minute) approximately 2,000 barrels per day of propane, 42 volume percent of which fiashes to vapor after passing through valve 16, must be passed from 1 through 15 to maintain the pressure in tank 6.

The propane in 1 containing about 4 mol percent ethane passes into heat exchanger 2 at a temperature of 90 F. and leaves through 3 at a temperature of 31 F. The propane in 3 passes through heat exchanger 4 and leaves therefrom at a temperature of 34 F. to pass through 5 into tank 6. The pressure of the liquid propane in 5 as it leaves heat exchanger 4 is 205 p.s.i.g.

Liquid propane at 90 yF. and 225 p.s.i.g. in 1 passes through 20 into receiver 21 which is maintained at 102 F. and 185 p.s.i.g. Relatively warm, high pressure propane passes from receiver 21 through 25 to valve 28 at a temperature of 102 F. and a pressure of 180 p.s.i.g. and at a rate of 177 gallons per minute. The liquid propane upon passing through valve 28 ashes 29 volume percent of the liquid to vapor. Heat exchanger 2 is maintained at a pressure of 40 p.s.i.g. which causes the temperature of the propane therein to be maintained at 21 F. Liquid propane leaves heat exchanger 2 through 30 at a temperature of 21 F. and a pressure of 40 p.s.i.g. at a rate of 86 gallons per minute and passes through valve 33 at which point 19.6 volume percent is flashed to vapor. Heat exchanger 4 is maintained at a pressure of about 14.7 p.s.i.a. or 20 to 30 inches of water pressure and therefore a consequent temperature of about 44 F. Propane vapors leave heat exchanger 4 through 34 at a rate of 4,160,000 standard cubic feet per day at a temperature of 44 F. and a pressure of less than 0.1 p.s.i.g. Substantially the same amount of propane vapors leaves scrubber 35 through 37 and enter compressor 38. The propane is discharged from compressor 38 at a temperature of 70 F. and a pressure of 40 p.s.i.g. Propane vapors leave heat exchanger 2 through 41 at a rate of 4,374,000 standard cubic feet per day at a temperature of 21 F. and a pressure of 40 p.s.i.g. The combined vapors from 41 Iand compressor 38 are compressed in compressor 44 to -a temperature of 175 F. and a pressure of 190 p.s.i.g. These hot, compressed vapors pass through heat exchanger 46 and are cooled to 102 F. and reduced to a pressure of 185 p.s.i.g. About 41,959 pounds per hour of propane passes through 47 into the receiver 21.

About 1,349,000 standard cubic feet per day of propane vapors containing about 80 volume percent propane and about 20 volume percent ethane at 20 F. and a pressure of less than 0.1 p.s.i.g. passes from tank 6 through 53 into scrubber 54 which is maintained at 20 F. and 14.7 p.s.i.a. Substantially all of these vapors pass from 54 through 71 into compressor 72 from which they are discharged at a temperature of 80 F. and a pressure of 35 p.s.i.g. They then pass through 73 into heat exchanger 4 and are removed therefrom as a liquid at a temperature of 34 F. and a pressure of 30 p.s.i.g. for return to tank 6 through 74, 65 and 5.

Reasonable variations and modifications are possible within the scope of this disclosure without departing from the spirit and scope of the invention.

I claim:

1. A method for cooling a liquid comprising providing a source of refrigerant under an elevated pressure, passing said refrigerant into a first heat exchange zone in which said refrigerant is maintained at a lower pressure than `said refrigerant source to lower the boiling temperature and therefore the temperature of the refrigerant in said zone, passing said liquid in heat exchange relationship with said refrigerant in said first heat exchange zone to cool same, removing liquid refrigerant from said rst heat exchange zone and passing same into a second heat exchange zone in which said refrigerant is maintained at a lower pressure than the pressure on said refrigerant in said first heat exchange zone to further lower the boiling temperature and therefore the temperature of same in said zone, removing said liquid from said first heat exchange zone and passing same in a heat exchange relationship with said refrigerant in said second heat exchange zone to further cool said liquid, removing said Iliquid from said second heat exchange zone, removing refrigerant vapors from said second heat exchange zone and compressing same substantially to the pressure maintained `in said first heat exchange zone, combining said compressed vapors from said second heat exchange zone with refrigerant vapors from said first heat exchange zone, compressing said combined vapors and cooling same to form at least in part a refrigerant `liquid at a temperature and a pressure substantially the same as that of said source of refrigerant under elevated pressure, and introducing said compressed and cooled combined refrigerant vapors into said source.

2. A method according to claim 1 wherein the refrigerant in said source is passed through an additional heat exchange zone prior `to passing through said first heat exchange Zone to preclean said refrigerant by collecting in said additional heat exchange zone liquified impurities, said `additional Iheat exchange zone being cooled by evaporation of liquid refrigerant supplied from said second heat exchange zone.

3. A method for removing a fluid from `a first source thereof and cooling additional fluid being yintroduced into the same source comprising withdrawing said fiuid from said source, introducing into said first source during said' withdrawal `at least part of said additional fiuid at a temperature and pressure higher than said fluid in said first source when the pressure in said source drops be- Ilow a predetermined minimum value, providing a second source of refrigerant under an elevated pressure, passing said refrigerant into a first heat exchange zone in which the refrigerant is maintained at a lower pressure than said refrigerant source to lower the temperature of the refrigerant in said zone, passing at least part of said additional fluid in a heat exchange relationship with said refrigerant in said first heat exchange zone, removing said refrigerant from said first heat exchange zone and passing same into a second heat exchange zone in which the refrigerant is maintained at a lower pressure than the refrigerant in said first heat exchange zone -to further lower the temperature of said refrigerant, removing said additional fluid from said first heat exchange zone and passing same in a heat exchange relationship with said refrigerant in said second heat exchange zone, removing said refrigerant vapors from said first and second heat exchange zones, compressing and cooling said vapors to form at least in part a liquid refrigerant at a temperature and pressure substantially the same as said second source of refrigerant, and introducing said at least in part liquid into said second source.

4. A method for removing a liquid from a first source thereof and precooling additional liquid with liquid refrigerant of the same kind before introducing the additional liquid into the same source comprising introducing a first part of said additional liquid into said first source at a temperature and pressure higher than the liquid already present in said first source when the pressure in said source drops below a `minimum value necessary to at least maintain the desired rate of withdrawal of liquid therefrom, passing a second part of said additional liquid into a separate second source of warm liquid refrigerant under an elevated pressure, passing said liquid refrigerant from said second source into a first lheat exchange zone which is maintained at a pressure lower than said liquid refrigerant in said second source `to lower the boiling temperature .and therefore the temperature of the refrigerant liquid in said first heat exchange Zone, passing a third part of said additional liquid in heat exchange relationship with said liquid refrigerant in said first heat exchange zone, removing said -liquid refrigerant from said first heat exchange zone and passing same into a second heat exchange zone which is maintained at a pressure loWer than the pressure on said refrigerant in said first heatexchange zone to further lower the temperature of said liquid refrigerant, removing the cooled third part of additional Iliquid from said first heat exchange zone and passing same in a heat exchange relationship with the liquid refrigerant in said second heat exchange Zone to further cool said additional liquid, removing said further cooled third part of additional -liquid from said second heat exchange zone into said first source, removing refrigerant vapors from said second heat exchange zone and compressing same to a pressure substantially the same as the pressure maintained in said first heat exchange zone, removing refrigerant vapors from said first heat exchange Zone and lcombining same with the compressed refrigerant vapors from said second heat exchange zone, compressing and cooling said cornbined refrigerant vapors to form a substantially liquid refrigerant `at a temperature and pressure substantially the same as the temperature and pressure of said second source of Warm liquid refrigerant under elevated pressure, and introducing the compressed and cooled, substantially liquid refrigerant into said second source.

5. A method according to claim 4 wherein the sole liquid employed is propane, the additional propane is at a temperature of 90 F. and a pressure of 225 p.s.i.g., the first source is at a temperature of 50 F. and a pressure of less than 0.1 p.s.i.g., the second source is at a temperature of about 102 F. and a pressure of about 185 p.s.i.g., .the first heat exchanger is at a temperature of about 21 F. and a pressure of about 40 p.s.i.g., the second heat exchanger is at a temperature of about 44 F. and 'a pressure of less than 0.l p.s.i.g., the vapors from the second heat exchanger are compressed to a temperature of about 70 F. and a pressure of about 40 p.s.i.g., the combined vapors are compressed to a ternperature of about 175 F. and a pressure of about 190 p.s.i.g., the combined vapors are cooled and returned to the second source at a temperature of about 102 F. and a pressure of about 185 p.s.i.g.

' 6. Apparatus for cooling a liquid comprising a storage container adapted to hold a supply of Warm refrigerant liquid under an elevated pressure, a first heat exchanger, a valved conduit openly connecting said container and said first heat exchanger, means for regulating the opening of the valve in said conduit responsive to liquid level in said first heat exchanger, a second heat exchanger, a valved conduit openly connecting sai-d first heat exchanger and said second heat exchanger, means for regulating the opening of said valve in said con-duit responsive to liquid level in said second heat exchanger, conduit means for passing a liquid to be cooled through said first heat exchanger and then through said second heat exchanger, first compression means for compressing refrigerant liquid vapors from said second heat exchanger, conduit means openly connecting said second heat exchanger with said first compression means, second compression means for compressing refrigerant liquid vapors from said first heat exchanger, conduit means openly connecting said first heat exchanger with said second compression means, conduit means openly connecting said first compression means with said second compression means, means for cooling compressed refrigerant vapor discharged from said second compression means, conduit means openly connecting said second compression means and said cooling means, and conduit means openly connecting said cooling means and said container.

7. Apparatus for cooling a liquid comprising a first storage container adapted to hold a supply of Warm refrigerant liquid under an elevated pressure, a first heat exchanger, a first valved conduit openly connecting said first container and said first heat exchanger, means for regulating the opening of the valve in said conduit responsive to liquid -level in said first heat exchanger, a second heat exchanger, a second valved conduit openly communicating with said first valved conduit in said first heat exchanger and said second heat exchanger, means for regula-ting the opening of said valve in said conduit responsive to liquid level in said second heat exchanger,

third conduit means for passing a liquid to be cooled through said first heat exchanger and then through said second heat exchanger, first means for compressing refrigerant liquid vapors from said second heat exchanger, four-th conduit means openly communicating with said second heat exchanger and said first compression means, second means for compressing refrigerant liquid vapors from said first heat exchanger, fifth conduit means openly communicating With said first heat exchanger and said second compression means, sixth conduit means openly connecting said first compression means with said second compression means, means for cooling the compressed refrigerant vapor discharged from said second compression means, seventh conduit -means openly connecting said second compression and said cooling means, eighth conduit me-ans openly connecting said cooling means and said first container, `a second container, third means for compressing vapors from said second container, ninth conduit means connecting said second container and said third compression means, tenth conduit means for passing the discharge from said third compression means through said second heat exchanger and into said second container.

S. Apparatus for removing a fiuid from a source thereof and for 4cooling that fluid before introduction of same into said source comprising a first container, a first conduit openly connected to said container for removal of fluid therefrom, a second conduit for supplying warm liquid to be cooled and stored to the system, a third conduit openly connecting said second container and said first container, a valve operatively mounted in said -third conduit, means for opening said valve when the pressure in said first container drops below a predetermined minimum value, a second container for holding Warm liquid to be used as refrigerant at an elevated pressure, a valved conduit openly connecting said second conduit and said second container, a first heat exchanger, a valved conduit openly connecting said Vsecond container and said first heat exchanger, a second heat exchanger, a valved conduit openly connecting said first heat exchanger and said second heat exchanger, conduit means for'passing Warm liquid to be cooled from said second conduit first through said first heat exchanger and then through said second heat exchanger and finally into said first container, means for compressing refrigerant vapors from said first and second heat exchangers, conduit means openly connecting said first and second heat exchangers with said cornpression means, means for cooling said compressed refrigerant vapors, conduit means openly connecting said compression means and said cooling means, and conduit means openly connecting said cooling means and said second container.

9. Apparatus for removing a liquid from a source thereof and for precooling the same liquid prior to introduction of same into said source comprising a first storage container, a first conduit openly connected to said container .for removal of liquid therefrom, a second conduit for supplying liquid to the system to be cooled and stored, a third conduit openly connecting said second conduit and said first storage container, a normally closed motor valve operatively mounted in said third conduit, pressure-sensing means operatively connected to the inferior 0f said first storage container and to said motor Valve and adapted to regulate the opening of said valve responsive to the pressure in said first storage container including opening said valve when the pressure in said first storage container drops below a preset minimum value, a second container for holding at an elevated pressure warm liquid to be used as refrigerant, a first valved conduit openly connecting said second conduit and said second container, means for regulating the opening of the valve in said first valved conduit responsive to the liquid level in said second container, a first heat exchanger, a second valved conduit openly connecting said second container and said first heat exchanger, means for regulating the opening of the valve in said second valved conduit responsive to the liquid level in said first heat exchanger, a second heat exchanger, a third valved conduit openly connecting said first heat exchanger and said second heat exchanger, means for regulating the opening of the valve in said third valved conduit responsive to the liquid level in said second heat exchanger, conduit means for passing liquid to be cooled from said second conduit through said first heat exchanger and then through said second heat exchanger and finally into said first storage container, first means for compressing refrigerant vapors from said second heat exchanger, conduit means openly connecting said second heat exchanger and said first compression means, second means for compressing refrigerant vapors from said first heat exchanger, conduit means openly connecting said first heat exchanger and said second compressing means, conduit means openly connecting said first compression means and said second compression means, means for cooling compressed refrigerant vapors, conduit means openly connecting said second compression means and said cooling means, and conduit means openly connecting said cooling means and said second container.

References Cited by the Examiner UNITED STATES PATENTS 2,964,916 12/ 1960 Keeping 62-55 X 2,976,695 3/1961 Meade 62-55 X 3,058,314 10/1962 Gardner 62-52 X 3,058,315 10/1962 Schuftan 62-53 X 3,106,827 10/ 1963 Schlumberger 62-55 X 3,148,966 9/ 1964 Kitchen 62-21 3,163,992 1/1965 Becker 62-55 3,191,395 6/1965 Maher et al, 62-52 X 3,195,316 7/1965 Maher et al. 62-52 ROBERT A. OLEARY, Primary Examiner. LLOYD L. KING, Examiner.

Claims

1. A METHOD FOR COOLING A LIQUID COMPRISING PROVIDING A SOURCE OF REFRIGERANT UNDER AN ELEVATED PRESSURE, PASSING SAID REFRIGERANT INTO A FIRST HEAT EXCHANGE ZONE IN WHICH SAID REFRIGERANT IS MAINTAINED AT A LOWER PRESSURE THAN SAID REFRIGERANT SOURCE TO LOWER THE BOILING TEMPERATURE AND THEREFORE THE TEMPERATURE OF THE REFRIGERANT IS SAID ZONE, PASSING SAID LIQUID IN HEAT EXCHANGE RELATIONSHIP WITH SAID REFRIGERANT IN SAID FIRST HEAT EXCHANGE ZONE TO COOL SAME, REMOVING LIQUID REFRIGERANT FROM SAID FIRST HEAT EXCHANGE ZONE AND PASSING SAME INTO A SECOND HEAT EXCHANGE ZONE IN WHICH SAID REFRIGERANT IS MAINTAINED AT A LOWER PRESSURE THAN THE PRESSURE ON SAID REFRIGERANT IN SAID FIRST HEAT EXCHANGE ZONE TO FURTHER LOWER THE BOILING TEMPERATURE AND THEREFORE THE TEMPERATURE OF SAME IN SAID ZONE, REMOVING SAID LIQUID FROM SAID FIRST HEAT EXCHANGE ZONE AND PASSING SAME IN A HEAT EXCHANGE ZONE TO FURTHER COOL SAID LIQUID, REHEAT EXCHANGE ZONE TO FURTHER COOL SAID LIQUID, REMOVING SAID LIQUID FROM SAID SECOND HEAT EXCHANGE ZONE, REMOVING REFRIGERANT VAPORS FROM SAID SECOND HEAT EXCHANGE ZONE AND COMPRESSING SAME SUBSTANTIALLY TO THE PRESSURE MAINTAINED IN SAID FIRST HEAT EXCHANGE ZONE, COMBINING SAID COMPRESSED VAPORS FROM SAID SECOND HEAT EXCHANGE ZONE WITH REFRIGERANT VAPORS FROM SAID FIRST HEAT EXCHANGE ZONE, COMPRESSING SAIDDCOMBINED VAPORS AND COOLING SAME TO FORM AT LEAST IN PART A REFRIGERANT LIQUID AT A TEMPERATURE AND A PRESSURE SUBSTANTIALLY THE SAME AS THAT OF SAID SOURCE OF REFRIGERANT UNDER ELEVATED PRESSURE, AND INTRODUCING SAID COMPRESSED AND COOLED COMBINED REFRIGERANT VAPORS INTO SAID SOURCE.