US2601763A - Apparatus for dispensing a liquefied gas - Google Patents

Description

July 1, 1952 p PEFF 2,601,763

APPARATUS FOR DISPENSING A LIQUEFIED GAS Filed Jan. 5, 1949 IN V EN TOR. PETER PEFF BY y mafiadaag ATTORNEYS Patented July 1, 1952 OFFICE ABPARATU SLFOR DISPENSING'fAZC LIQUEFIED GAS This'invention.relates=to apparatusfor storing, v transportingand dispensing a liquifiedgas= from a container, andto' a method of sub-coolin such liquified "gas, preferably"'adjacent the" point of withdrawal from the containers lli'i's apparatus and: method are particularly suitableforliquifid gases having 1 boiling i point "temperatures" at atmosphericipressure"below 273 Kij one'example of which is liquid. oxygen'au SIM) with which this invention-us =concerne'd7 were storedn and transported at:relatively low -pres sures in insulated containers; However? a certain-- amount of evaporation is inevitable because -of unavoidable heat leaks-4n the'insulation. Many times thisigas or a considerable portion thereofy hassbeen: exhausted and 1ost-= when the pressure hasurisen to a predetermined degree.-

Prior to :the present-time"; relatively expensive and complicated means has= been emplo'y'ed to sub-cool the liquid gas before' pumping th'e samefrom; the container: in rorderwto insure-"proper operation :ofathe pump;

One. of the .robjects of the present "invention-is the provisioniof :improvedapparatu's and an im':

proved method for utilizingthegas'ofevaporationrfor sub-coolingthe liduid in the containerto insure proper roperationrrofithepump. ---Thus, -the gas; of :evaporationzis n'otwasteda nor is apparatus" required; sfor :bottling th'e' same in: :ord'en to 'save suchrr possible zwaste; and at -the :sametime; "the liquid gas is sub-cooled.

Anotherohj ect of theinvention is the provisi'om of an improved construction and arrangementmf comnonentadevices apparatus orthe characterlwdescribedawhereby? the storingntransporting andidispensing ofsliquified gasris more eflici'entlyand: simplyiefl'ectedithan heretofore. 1

Anothermobjectzof the inventionis the provisiorl of simple and :efi'ective :means -for converting the abling the control of gas pressure within said" tank Ito facilitate apumpingzliquid gasrtherefro'm It is a well'rkn'own' :fact: rthat the 'standardz reciprocatingtliquid oxygen pumps will'not pump 7 within said chamber at a Ievelabovethe opening liquid oxygemunless theoxygen is cooled down'to a temperature :belowits boiling pointunder what--- ever pressure is onithel'liquid' oxygen-inithe pump" chamber: Thereasontfor' thisvis thatthe liquid oxygen pump l5 has its lower oxygenkeeps evaporating all-the time 'andtcauses vapor-clock in-"the-pump: By' sub-cooling the liquid:oxygemthat is .deliv'eredvto the inlet valve" of therpump; vapor-lock: is eliminated:

One of the objects of"this inve'ntion is to-" eliminate vapor lock-inan efilcient mann V employment of the gas of evaporation in tli'e liquid gas" container from which "the liduidg'a is pumped.

Other objects and advantages will apq5fe the description and in the drawing and be understood that the invention' is not t' restrioted to oxygen gas,- since it would ab ipl i'cable to gases having the-same character t'i'c off 'liquification at relatively low 'tempera'tu The drawingis diagrammatic,andis illust tive of the invention I V p In the drawing, l represents-the inner shell-ofb a container-generally designated 2; adapted to receive and holda charge 3 of liquifidfgaa-suc as oxygen,-vv i-th'=a space 4 above the level oftli liquid in said container in whichgas ofe'vapora tion is held, 'and which gasapplies-a pressure'onthecharge3k 4 Said shell I is enclosed by-heat insulation terial 5 that'is-betweeninner shell i ans-as outer'shelltx g Y Communicating' with the interior of jth e m" container 2 is a pump chamber 1. A passage'wa 8 connects the chamber -1 with the interior container 2 through the bottom ofthe* 1atter. j Chamber! and passageway 8 are enclosed by heat insulation material 9. 7

Connected withthe container: 2 at"the top thereof'is a-safety valve In and pressure gauge? H for' respectively effecting a releasefo f gas o evaporation within thecontainer should thepr surei'ncrease to the danger point, and to indicat the pres'su're "within said tank." These are coir ventional devices on practicallyalltanks ott general nature: h

A pipe 1 2 thatc'arri'es the gauge ll sm vawe [0 also constitutes the means" for filling-the tainer wh'ena cap -13 closing said pipe is re moved. v

The outer shell 6 of"container 2 is alsopr videdwitha conventional relief valve ford charging any "gas that may leak-into the s ace containing the insulation 5.

Passageway-B opens intothe upper'end of-the pump chamber 1 so that there will be no spac of passageway 8 into *saidchambe'r. v

A conventional reciprocating or plunger type end 'proj ecting' into saidchamber I. An inlet'lfi provided with the j usual inlet valve is at the lower end of pump [5 and an outlet llprovided with theconventionall outlet valve'is also at the lower end or the'pumd and in chamber?- h An outlet pipe I8 connects with the outlet and may lead through any suitable vaporizer IQ for evaporation of the liquid oxygen, and from said vaporizer the oxygen may be pumped into the conventional containers or piped elsewhere for use.

From the upper end of container 2 extends a conduit that extends spirally around the inner shell I in a downward direction, being imbedded in the insulation material 5, but progressively moving outwardly from the inner shell I toward the outer shell 6 from the upper to the lower end of the spiral portion thereof that is between said shells. At its lower end the conduit 20 passes outwardly through the outer shell at a point adjacent the lower end of the container 2.

From the above structure it will be seen that the portion of conduit 29 that is between shells I, 6 progressively moves to a warmer zone in the insulation material as it moves toward the point of emergence from the outer shell 5.

This conduit 20 is adapted to carry the oxygen of evaporation from the space 4 above the liquid oxygen 3 in container 2, and this oxygen is the oxygen-reaches the compressor it is at substantially room temperature, and said oxygen is drawn into the compressor where it is compressed to a medium pressure.

Inasmuch as there will be an increase in the temperature of the oxygen gas due to compression, the compressed gas is conducted through a pipe through anysuitable heat exchanger 25, where it is cooled. This heat exchanger may use air or a cooling fluid or any conventional cooling means.

From the heat exchanger, thepipe 25 passes into the container 6 through conduit 20, being spaced within said conduit. By this arrangement there will be a heat exchange between the outfiowing gas and the incoming compresed gas, the latter being progressively cooled as it flows back through pipe 25 counter to the flow of gas outwardly through conduit 20.

The pipe 25 passes into container 2 through the upper end thereof and then through the liquid oxygen 3 within said container to passageway 8, and through passageway 8 into the pump chamber 1 where it is provided with an expansion valve 21. A hand wheel 28 accessible from outside the container and chamber 1 is provided for manually manipulating said valve.

In certain installations the valve 21 may be positioned within the body of liquid that is in the container, in which case the pipe 25 would terminate within said container.

The compressed oxygen from the compressor thus flows through the pipe 25 counter or opposite to the direction of flow of the gas of varporization in conduit 20. 1

From conduit 20 the pipe 25 extends into the liquid oxygen, and is gradually cooled down to the temperature of the liquid oxygen, becoming liquid, and after such liquification it is expanded by means of expansive valve 21 and is discharged into the pump chamber 1 or within the container 2, according to the installation. The use of a pump chamber and the discharge of the liquid oxygen from pipe25 into the liquid oxygen in the pump chamber is preferable. If the liquid were discharged into the body of liquid '25 outside said container.

within the container 2, sub-cooling of said body would occur, but it would be slower.

In order to provide for a rapid and eflicient regulation of the pressure in container 2, a second pipe may extend through conduit 20' to outside the container 2, and connect with pipe A manually manipulatable valve 3| in pipe 30 outside the container 2 is provided to enable gas from pipe 25 to be admitted into the container 2 through pipe 30. The pipe 30 preferably terminates within container 2 above the level of the liquid in the latter.

The pipe 30 may pass directly through the container walls to the outside without passing through conduit 20, if desired, or in some installations, the valve could be connected in pipe 25 Within the container and above the level of the liquid within said container. In any event, when and if desired, the above structure is intended to provide means for releasing compressed oxygen from pipe 25 within the container 2 and into space 4, which would be helpful when the pump I5 is in operation by creating some back pressure for said pump.

Compression of the gas phase of the liquid in containers similar to that shown herein is known to the trade, but for the purpose of reducing the pressure in the container, or to produce a certain amount of refrigeration by causing the liquid in the container to evaporate, or for increasing the purity of the liquid oxygen in the system. Sometimes this evap'orated'oxygen gas has been compressed and either returned to the oxygen producing column or it has been delivered to a gas holder or to a high pressure oxygen compressor to compress it for storing into cylinders. However, I am not aware that anyone has heretofore compressed the evaporated gas, precooled, and expanded the same in the manner and for the purpose described in this invention.

It is obvious that in certain instances the liquified gas, after compression and cooling could be expanded in the container 2, particularly where the pump is in said container. The pump chamher is preferable, however.

It is also obvious that the conduit 20 need not in all instances be imbedded in the insulation between shells l, 6 in its spiral course. In some instances the coil could be positioned outside the container, although the structure shown is usually preferable.

A drain valve 32 may also be provided in the pump chamber.

; The evaporator l9 may be of any desired type. In some instances, the heat from the exhaust gases from the engine of a vehicle is employed for supplying the heat, particularly where the container is mounted on such vehicle, it being understood that the present invention is particularly adapted for being mounted on a truck or vehicle during transportation of the liquid gas from one place to another. The invention is not, however, to be restricted to such use.

I claim:

1. Apparatus for dispensing gas'material'that has a boiling point temperature below 273 K.

which comprises a thermally insulated container for holding a charge of said material below its boiling point temperature under-a predetermined pressure of such gas material in said container in the gaseous phase, a discharge pump having an inlet in communication with such charge in said container, a conduit opening at one end into the upper end of said container for communicating with the said gas in such gaseous phase and amines;

terminating at its opposite end within the charge adapted-to 'be held in said container, said con-'- cluit 'e'xtendingoutwardly of said container be-' 1 tween "its opposite end: portions andincluding" a I compressor for withdrawing and compressing" adjacent said opposite endbeing positioned within said cha'rge' for a substantial distance and in direct heat transfer relation with suchcharge for reduc'ing the'temp'erature' of the gas' therein to below 273 a valve in said c'ondu-it 'and po-- sitioiied within saidcharge for controlling the dischargeof liquified gas material therefrom into 1 said- Ichargeand'under the pressure of saidcom' 2. Apparatus for dispensing gas material that has a boiling pointtemperature below 273K.

Which-comprises a thermally insulated container for'holding a charge of said material below its boiling point temperatur under a predetermined pressure of such gas material in said container'in the gaseous phase, a discharge pump having an inlet in communication with such charge in said container, a conduit opening at one end into the upper end of said container for communicating with the said gas in such gaseous phase and ter-.

minating atitsopposite end within-the charge adapted to beheld in said container, said conduit extending outwardly of said container between its opposite end portions and including a com pressor for withdrawing and compressing part of said gasinits gaseous phase, a heat exchanger between said compressor and said container for cooling the ga compressed by said compressor,

and the end portion of said conduit that is adjacent said opposite end being positioned within,

said charge for a substantial distance and in di-'" rect heattransfer relation with'the charge for reducing the temperature of the gas therein to below 273 K., a valve in said conduit and positioned within said charge for controlling the discharge of liquified gas material therefrom into said charge and under the pressure of said compressor, a substantial length of said conduit between said valve and said heat exchanger being spaced within and extending longitudinally of a corresponding length of the conduit extending from the upper end of said container to said compressor, whereby said lengths will be in heat exchange relationship to each other.

3. Apparatus for dispensing gas material that has a boiling point temperature below 273 K. which comprises a thermally insulated container for holding a charge of said material below its boiling point temperature under a predetermined pressure of such gas material in said container in the gaseous phase, a discharge pump having an inlet in communication with such charge in said container, a conduit opening at one end into the upper end of said container for communicating with the said gas in such gaseous phase and terminating at its opposite end within the charge adapted to be held in said container, said conduit extending outwardly of said container between its opposite end portions and including a compressor for withdrawing and compressing part of said gas in its gaseous phase, a heat exchanger between said compressor and said container for cooling the gas compressed by said compressor, and the end portion of said conduit that is adjacent said opposite end being positioned within said charge for a substantial distance and in direct- "heat transier -relation with "the: charge for reducing'the"temperature of the gas therein" 1:- to below 273 K; a valvein saidconduitfor: con

trolling*the' discharge of cliq'uified gas material therefrom into "said charge and under the pres sure'of said compressona heat insulated well be-: low -saidcontainer "and: in communication there-1 with and a' passageway communicating. between-x the bottom of "said container and saidwellcfor 1' conducting-said material into said well; said inlet:

and sai'd valvbeingflin said well.

4. Apparatus for dispensing liquid gas .matei rial :that :has boiling point temperature "below: 273 which comprises a thermally insulated container for holding:a charge of said materialibelow.- its boilingxpoint itemperature under the pressure of the gas of evaporation from said gas a material in said container, a discharge .pumpr." having: an inlet 'in communication with such 7 charge in said. containerja conduit openinginto 1 the upper 'end of said. container at one end for conducting said gas of evaporation from said: 1 container, a compressor connected with said con-"- duit for compressing the 1 gas so conducted from said container, heat exchange means for "cooling theigas' 'compressedby said compressor, a pipe extending fromisaid compressor and l'lGttBX-i changer-" into "saidcontainer. and through: the liquid: gasmaterial in said-container.under the: pressure: o'f-said compressor-for reducing the temperature of said material in said. pipe to substantially the temperature of the charge'in said container "and below 'the- .boiling point 1 thereof means comprisin said compressor for applying 1 a greatei 'pressure to the liquified gas material in said pipe than that of the pressure of the gas of evaporation'in said container; said pipe extending to a point a'djacent said inlet, and a valve in. said pipe and positioned within. said 1 charge i'for: releasing- :the liquified gas material therein intdthe -liqiiidgas-= material in said con- .container, a compressor connected with said conduit for compressing the gas so conducted from said container, heat exchange means for cooling the gas compressed by said compressor, a pipe extending from said compressor and heat exchanger into said container and through the liquid gas material in said container under the pressure of said compressor for reducing the temperature of said material in said pipe to substantially the temperature of the charge in said container and below the boiling point thereof, means comprising said compressor for applying a greater pressure to the liquified gas material in said pipe than that of the pressure of the gas of evaporation in said container, a branch from said pipe opening into said container, and a valve in said pipe and positioned within said charge for releasing the liquified gas material therein into the liquid gas material in said container, a valve in said branch to permit release of gas material gaseous phase in said branch into said container for increasing the gas pressure on said charge as desired, said branch being connected with said pipe at a point where the material in said pipe is still in the gaseous phase.

6. Apparatus for dispensing gas material that has a boiling point temperature below 273 K. which comprises a thermally insulated container for holding a charge of said material below its boiling point temperature under a predetermined pressure of such gas material in said container in the gaseous phase, a discharge pump having an inlet in communication with such charge in said container, a conduit opening at one end into the upper end of said container for communicating with the said gas in such gaseous phase and terminating at its opposite end adjacent said inlet and in communication with a charge adapted to be held in said container, said conduit extend-' ing outwardly of said container between its opposite end portions and including a compressor for withdrawing and compressing part of said gas in its gaseous phase, a heat exchanger between said compressor and said container for cooling the gas compressed by said compressor, and the end portion of said conduit that is adjacent said inlet being positioned within said charge for a substantial distance and in direct, heat transfer relation with the charge for reducin the temperature of the gas therein to below 273 K., a valve in said conduit adjacent said inlet for controlling the discharge of liquified gas material therefrom into said charge and under the pressure of said compressor.

'7. Apparatus for dispensing gas material that has a boiling point temperature below 273 K. which comprises a thermally insulated container for holding a, charge of said material below its boiling point temperature under a predetermined pressure of such gas material in said container in the gaseous phase, a discharge pump having an inlet in communication with such charge in said container, a conduit opening at one end into the upper end of said container for communicating with the said gas in such gaseous Phase and terminating at its opposite end adjacent said inlet and in communication with a charge adapted to be held in said container, said conduit extending outwardly of said container between its opposite end portions and including a compressor for withdrawing and compressing part of said gas in its gaseous phase, a heat exchanger between said compressor and said container for cooling the gas compressed by said compressor, and the end portion of said conduit that is adjacent said inlet being positioned within said charge for a substantial distance and in direct heat transfer relation with the charge for reducing the temperature of the gas therein to below 273 K., a valve in said conduit adjacent said inlet for controlling the discharge of liquified gas material therefrom into said charge and under the pressure of said compressor, a heat insulated well in communication with said container and a passageway communicating between the bottom of said container and said well for conducting said material into said well, said inlet and said valve being in said Well.

PETER PEFF.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,371,427 Kerr Mar. 15, 1921 1,905,971 Davisson et al Apr. 25, 1933 2,033,094 De Motte Mar. 3, 1936 2,389,106 Marshall et a1 Nov. 13, 1945 2,451,151 Byram Oct. 12, 1948 FOREIGN PATENTS Number Country Date 8,661 Australia 1932

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