US1982789A

US1982789A - Method of refrigeration and apparatus therefor

Info

Publication number: US1982789A
Application number: US591524A
Authority: US
Inventors: Clark Walter Gordon
Original assignee: Air Ice Res & Dev Corp
Current assignee: Air Ice Res & Dev Corp; Air Ice Research & Development Corp
Priority date: 1932-02-03
Filing date: 1932-02-03
Publication date: 1934-12-04
Anticipated expiration: 1951-12-04

Description

- Dec. 4, 1934. w. G. CLARK 1,982,789

METHOD OF REFRIGERATION AND APPARATUS THEREFOR Filed Feb. 8, 1932 3 Sheets-Sheet l fn'uentor 1 ltorneyS 3 Sheets-Sheet 2 Inventor 1 l/UI'IIQVA Dec. 4, 1934. w. G. CLARK METHOD OF REFRIGERATION AND APPARATUS THEREFOR Filed Feb. 8, 1932 METHOD OF REFRIGERAiION AND APPARATUS THEREFOR Filed Feb. 8, 1952 5 Sheets-Sheet 3 ZHIHH PatentecLDec. 4, 1934 METHOD OF REFRIGERATION AND APPARATUS THEREFOR' Walter Gordon Clark,

Los Angeles, Calif., as-

signor to Air Ice Research 8; Development Corp., Los Delaware Application February 8,

25 Claims.

This invention relates to novel methods of utilizing gasifiable refrigerants and to certain forms ofapparatus wherein the methods of this invention may be effectively carried out. 'The' in- 5 vention also relates to methods and apparatus in which various physical properties of gasifiable refrigerants and of liquids are made available in the performance of novel functions and results.

By' the term gasifiable refrigerants" as used 10 hereinafter, reference is made to material such as liquefied or solidified carbon dioxide, sulfur dioxide, methyl chloride, etc. For purposes of lucidity, the subsequent description of the methods and apparatus embraced by this invention will be particularly directed to methods and apparatus capable of being carried out or used.

- stand pressures of 900 pounds or more, with an additional satisfactory margin of safety. A container of dimensions suflicient to receive blocks 1 of solid carbon dioxide of commercial size, would under the above state of conditions, be exceedingly heavy. Furthermore, it is extremely difficult to provide a gas-tight seal without resorting to threaded or bolted joints which are slow and ture either contemplated extremely heavy and complicated devices, or did not fully utilize the refrigerating capacity of the materials.

This invention, on the other hand, provides means for storing and dispensing gasifiable refrigerants such as solid carbon dioxide, in a simple and effective manner. The pressure generated by vaporization or sublimation of a gasiflable refrigerant is utilized in sealing, strengthening and heat insulating the containers in which it is kept. The vaporization or sublimation of the refrigerants is controlled so as to maintain the Angeles, Calif., a corporation of 1932, Serial No. 581,524

refrigerant at any desired and predetermined maximum pressure. Furthermore, the expansion of the gasifiable refrigerant is controlled for the purpose of regulating the production of further quantities of gasified refrigerant in quantities commensurate with theamount of refrigeration required.

In addition, the gasified refrigerant may be caused to perform useful work so that not only may a proper refrigerating temperature be main: tained in refrigeration chambers, but the refrigerant may be caused to disseminate, mix with and circulate within any enclosure which it is desired to maintain at a relatively low temperature.

Moreover, the invention relates to a method of regulating the pressure of gasiflable refrigerants within a container by means of secondary refrigerants or freezable liquids. It concerns itself with novel methods of heat insulating refrigerators, refrigeration chambers or other compartments which it is desired to maintain at a low temperature; The methods of this invention may be applied to the insulation of cold storage receptacles, dispensing containers, refrigeration chambers, etc., and with the regulated supply of gasifled refrigerants to enclosures, rooms, box cars, and the like, for the purpose of keeping such enclosures cool.

arrangements ofyelements whereby the various objects and results to which the methods of this invention are directed, may be attained. It relates, for example, to the production of means whereby gasifiable refrigerants may be maintained at any predetermined maximum pressure within light weight dispensing containers; to the construction of refrigeration control units; to the construction of refrigerators; to the provision of means whereby the expansion characteristics of gasifiable refrigerants may be utilized to best advantage; to the provision'of means whereby gasified refrigerants may exert a controlled refrigerating effect and thereafter function to produce and maintain heat insulators, etc.

An object of this invention is to disclose and provide methods of utilizing gasifiable refrigerants for the refrigeration of chambers, cold storage containers, enclosures, and the like.

Another object of this invention is to disclose and provide a method of circulating gasified refrigerants within enclosures which it is desired to supply with a gasified refrigerant.

Another object of this invention is to disclose and provide a method of storing and dispensing gasified refrigerants.

An object of this invention is to disclose and provide a method of storing and dispensing refrigerants from limited containers in which said The invention also concerns itself with novel refrigerants are maintained at or below a predetermined maximum pressure.

A further object of this invention is to disclose and provide a method of utilizing the heat absorbing capacity of vaporization of gasifiable refrigerants for maintaining said refrigerants at a desired pressure and for utilizing refrigerating capacity of said refrigerants most effectively.

'Another object is to disclose and provide a. method of utilizing the heat absorbing capacity of vaporization of gasiflable refrigerants for the purpose of maintaining a secondary refrigerant in refrigerating relation to the gasiflable refrigerant, said secondary refrigerant acting as a structural material and at the same time acting as a heat insulating material.

Furthermore, it is an object of this invention to disclose and provide a method of insulating refrigeration chambers, cold storage receptacles, dispensing containers for gasiflable refrigerants, and similar objects or bodies with a freez- 1 novel means for regulating the able liquid.

Moreover, it is an object of this invention to disclose and provide means whereby the various objects enumerated hereinabove, as well as others, may be readily attained. For example, it is an object of this invention to disclose and provide a novel and effective construction for dispensing containers for gasifiable refrigerants.

Another object of this invention is to disclose and provide a novel cold storage or refrigerator construction.

A still further object is to disclose and provide gasiflable refrigerants.

These and other objects, uses, advantages, functions and results of this invention will become apparent to those skilled in the art from the following'description of the invention.

Although the invention may assume a great variety of forms and may be applied to a plurality of different uses, the detailed description will be limited to certain illustrative embodiments shown in the appended drawings, in which Fig. 1 is-a vertical section through one form of dispensing container for gasiflable refrigerants.

Fig. 2 is an enlarged longitudinalsection through a form of thermostatically controlled valve regulating means.

Fig. 3 is a front elevation, partly broken away, of a portion of a refrigerator embodying the invention. 1

Fig. 4 is a side elevation, partlybroken away, of the refrigerator illustrated in Fig. 3. 4

Fig. 5 is a front elevation, partly broken away, of a refrigeration control unit particularly adapted for use in cold storage houses, box cars, etc.

Fig. 6 is a side elevation, partly broken away, of the refrigeration control unit illustrated in Fig. 5.

As shown in Fig. 1, a suitable dispensing container for gasiflable refrigerants may consist of a cylindrical container 1 provided with a bottom 2. The container 1 may be provided with an inlet and in the case of cylindrical containers, the openend of the cylinder may comprise the inlet. A suitable closure membergor cap is provided for the inlet to the container. Preferably, the closure member is in the form of a cap adapted to encircle a portion of the container adjoining the inlet. As shown in Fig. 1, the cap 3 may be provided with a downwardly extending flange 4. The cap preferably flts loosely over the inlet to the container. A plurality of circum'ferentially vaporization of arranged. spacing pins or othersuitable spacing means such as protuberances 5, may extend inwardly from the flange 4 so as to space the flange 4 from the container 1. A plurality of outwardly extending circumferentially spaced pins or flange segments may extend from the upper edge of the container 1. The purpose of these spacing means 5 will be evident from the subsequent description. The closure member 3 may be provided with an outlet 6. Furthermore, the closure member may be provided with a suitable heating means such as, for example, an electrical resistance coil 7 carried within a cavity within the closure member. Preferably, the resistance coil is carried both in the top and in the flange of the closure member. A suitable terminal or plug 8 is carried by the closure 3, facilitating the supply of electrical energy to the coil 7 whenever it is desired to heat the coil. The container 1 is preferably positioned ina case 10. The case 10 may well be made of light metal and'provided with expansion joints r corrugations capable of permitting the case to expand slightly. The container 1 is preferably spaced from the walls of the case 10, suitable spacing means being provided to insure'this result. Although any form of spacing means may be used, Fig. 1 indicates bent metal spacers 11 for this purpose. Any suitable liquid is placed in the space between the container 1 and the case 10, the liquid extending up to about the top of container 1 and being permitted to enter the space between the flange 4 of the closure and the container 1. I I

If a container of this general character is fllled with a gasiflable refrigerant, such as solid carbon dioxide, and a closure placed over the inlet, (it being assumed for purposes of discussion that the closure is provided with an aperture or outlet such as the outlet 6), and the filled container then in' serted into, a case filled with water, the vaporization of the solid CO: within the container 1 will quickly cause the water to freeze. The ice thus formed substantially encloses the container 1 and seals the closure 3 upon the inlet to the 'container 1. In this manner, the temperature within the container 1 is maintained at about 32 F. and for this reason, the pressure within the con- .tainer is automatically limited to approximately 500 pounds per square inch. It has been found that an ice seal of the character employed between the container and the closure, has a strength of about 250 pounds per square inch and therefore pressures which are much in excess of 500 pounds per square inch, could be maintained within a container and the container sealed with ice, whenever ice is the seal between a closure member and the container. Furthermore, it has been found that ice below 32 F; has a thermal conductivity of only about 1.88 B. t. u.

per square foot per hour per 1 inch thickness per 1 F., and is therefore comparable to cork insulation in effectiveness. Moreover the ice en'- circling and substantially enclosing the container 1 materially increases the strength of the'container.

It is evident, therefore, that the container construction described he'reinabove employs a frozen liquid to perform a plurality of novel functions. The frozen liquid not only acts as a seal but insulates the container and strengthens-it. Furthermore, the maximum pressure capable of being developed within the container is regulated by the freezing point of the liquid exteriorly of the container. Instead of .using'water, saturated or supersaturated solutions, brine, alcohol solutions,

glycerine solutions, and other freezable liquids. or mixtures may be employed. In this manner, the maximum pressure of a gasifiable refrigerant within a limited container may be regulated by varying the freezing point of a body of liquid substantially enclosing said container. .The heat absorbing capacity of vaporization or sublimation of the gasifiable refrigerant is therefore utilized in maintaining a secondary refrigerant in refrigerating relation to the gasifiable refrigerant, and as long as suflicient heat absorbing capacity exists within the container 1 to maintain the liquid frozen, a pressure corresponding to the vapor pressure of the refrigerant at the freezing temperature of the liquid surrounding the container, will be maintained in the container.

As the maximum pressure capable of being generated within the container is thus controlled, it is not necessary to employ heavy construction for the container 1. When handling the solidified CO2 and using water ice as the sealing means, it has been found that the container may be made of steel to A" in thickness. The exterior case 10 may be extremely light, being capable of only withstanding a pressure of 4 or 5 pounds per square inch.

When the frozen liquid seal melts so that the cap is moved upwardly by the action of the gas pressure within the container 1, the cap is prevented from being completely blown off by interengagement of the inwardly extending flange sections 5 and the outwardly extending flange sections or pins carried by the upper edge of the container 1. It is to be understood that it'is necessary to partially rotate the cap upon the container 1 before the cap may be removed.

Whenever it is desired to refill the container 1, a current may be supplied to the resistance coil 7 in the closure member, thereby melting the seal and permitting'the cap to be removed. Preferably, a pressure release valve is carried by the closure member 3 so that a pressure of say 500 pounds, is liberated before the closure is heated and unsealed from the container.

Although in the description given hereinabove reference" has been made to a cylindrical container 1, it is to be understood that the containers may be of any desired shape or size. Cylindrical forms are preferred because of their compactness, adaptability and high strength.

Dispensing units of the type illustrated in Fig. 1 may be utilized wherever it is desired to store or dispense a gasifiable refrigerant. For example, they may be installed in refrigerated showcases, soda fountains and carbonated beverage dispensers, refrigerators, cold storage rooms, and the like. When it is desired to dispense carbon dioxide-from a container of this sort in regulated quantities so as to maintain a desired low temperature in an enclosure such as a refrigerator, the container may be inserted into the refrigerator, the closure member being then provided with a thermostatic valve 12 positioned in a conduit leading to the container 1. For example, the valve 12 may be connected to the outlet .6 formed in the ,closure member 3.- The body portion of the valve f2 may be provided with a conical seat 13 and a conical valve 14 adapted to cooperate with said seat. The valve member 14 may be in the form of a rod made of a metal having negligible coeflicient of expansion. The upper end of the rod may be provided with an 'exteriorly threaded head 15 held in position within a tubular member 16 attached to the body 12 of the valve. The tubular member 16 may be made of brass or other metal end of a rear vertical partition 28 joining the or alloy, having appreciable coefficient of ex pansion. Means may be provided for adjustably positioning the valve member 14 within the tubular member 16 as, for example, the groove 17, whereby the head 15 and the rod 14 may be rotated within the tube 16, thus longitudinally moving the-valve member 14. An outlet 18 may lead away from the valve body 12.

By exposing. the thermostatic valve 12, and particularly the tubular portion 16 thereof, to the action of gases within the chamber which it is desired to refrigerate or cool, the volume of carbon dioxide or other gasifled refrigerant discharged from the container 1 through the outlet 18 into expansion conduits, cooling coils, or the like, may be automatically controlled. Variations in the temperature of the gases within the chamber being refrigerated cause the member 16 to expand and contract, thus changing the setting of the valve and regulating the passage of gasified refrigerant therethrough.

Figs. 3 and 4 illustrate one form of refrigerator of high capacity, embodying forms of construction and methods embraced by this invention. A refrigerator of the type there shownis particularly adapted for use in hotels, homes, railroad dining cars, etc. It preferably comprises a suitable exterior housing 20 lined with insulating material 21. A thin metallic but water-tight liner 22 is positioned within the case..

Vertical partitions

23 and 24 are then positioned within the refrigerator, the partition 23 being spaced from the interior sheathing 22 as by means of

tie members

25 and 26. The

tie members

25 and 26 may be corrugated so as to permit expansion. The sheathing or liner 22 as well as the

partitions

23 and 24 may also be of corrugated metal.

A'horizontal member 27 may connect the lower ends of

partitions

24 and 23 as well as the lower rear portions of

side partitions

23 and 24. Inv effect, therefore,

partitions

23, 24 and 28 form an'enclosure connected to the front of the refrig erator and supported above the inner liner 22" by means of expansible supporting members 29.

The

vertical side partitions

23 and 24 may be connected together by means of

members

30 and 31, these members supporting suitable glazed or

enameled refrigeration chambers

32 and 33. The open ends of these

refrigeration chambers

32 and 33 may be fastened to the front wall 34 of the refrigerator and be provided with suitable doors by means of which access may be gained thereto. The refrigeration chamber 35 maybe supported above the bottom partition 27 by means of suitable supports 36. r A suitable container for gasiflable refrigerants, such as the container 1', may be positioned in the refrigerator, said container being provided with a closure member 3 bearing a relief valve 40. Conduit means may communicate with the interior of the container 1 such as, for example, the conduit 41, said conduit leading to a thermostatic-ally controlled valve 42 exposed to the gases in one of the'refrigerating chambers of the re- 1 frigerator.

As shown in Figs. 3' and 4, the thermostat tube 16 of the thermostat valve 42 extends 'into the refrigeration chamber 32; the gasified refrigerant passing through the valve 42 passes through suitable coils suround'i'ng the

refrigeration chambers

33 and 35. The refrigerant, after passing through thermostat valve 42, may be discharged by conduit 43 and pass through a series of co ls 44 around the lowermost refrigeration chamber i 35 andthen through coils 45 around the intermediate refrigeration chamber 33. The partially-expanded refrigerant may then pass by conduit 46 into the upper part of the refrigerator and be discharged into the insulation 21 therein. In actual operation, the space within the resfrigerator, that is, the space within the inner lining or sheathing 22 and between said sheath- ,ing and the

interior partitions

23, 24, 28 and 27,

is filled with water or other suitable liquid. Such water preferably extends upwardly to a height sufficient to substantially encircle and cover the container for gasifiable refrigerants 1'. The liquid level is indicated in Figs. 3 and 4 at 50. The gasifiable refrigerant vaporizes in thecontainer l' and is discharged through conduit 41. The vaporization of the refrigerant causes the water or other liquid surrounding the container 1', to freeze, thereby sealing the closure member 3' and permittingthe generation of pressure within the container 1'.

The thermostatic valve 42 responds to the temperature of the air within the refrigeration compartment 32 and permits the discharge of gasifled refrigerant through the valve 42 and through conduit 43 into the coils 44 and 45, thereby reducing the temperature in

refrigeration chambers

35 and 33 to a desirable low point. Inasmuch as the refrigerant is being. expanded in close proximity to the water-filled walls of the refrigerator, the water or other liquid therein freezes, forming a heat insulating layer surrounding the

refrigeration chambers

33 and 35. The partially expanded refrigerant is then discharged by conduit 46 into the layer of insulating material 21 contained in the outer envelope of the refrigerator. Preferably, the heat insulating material 21 is porous and permits the passage of carbon dioxide therethrough.

It has been found that layers of corrugated paper, loosely packed mineral wool, and similar materials form very effective insulation. In-

.sulating boards or panels made of corrugated paper are particularly effective. The carbon 4 dioxide sinks downwardly through the insulation,

displacing the moisture laden air generally existing in the pores of any insulating material, and

eventually the expanded carbon dioxide or other gasifiable refrigerant is discharged through suitable apertures 51 formed in the sub-floor of the refrigerator.

It will benoted that in a refrigerator of the .type shown in Figs. 3 and 4, the refrigeration chambers are insulated by means of a freezable liquid. Furthermore, the freezable liquid assists in retaining and forming a container for the gasifiable refrigerant. The gasified refrigerant controls its own rate of escape from the container 1' as the thermostatically controlled valve 42 responds to variations in temperature changes and such temperature changes are occasioned by the expanding refrigerant. thermore, the vaporization or sublimation of the refrigerant in container 1 forms a body of ice or secondary refrigerant around said container, the further expansion of the refrigerant in the expansion conduits or coils reduces the temperature of the refrigeration chambers and freezes the insulating layers of ice, and the final stage of expansion of the refrigerant in the insulating lining 21 materially assists in maintaining the contents of the refrigerator at a uniformly low temperature. Ordinary heat insulating materials contain mo'sture laden air, as has been stated hereinbefore, and moisture laden air has Fur a relatively high specific heat and is not an effective insulator. When solid carbon dioxide is the refrigerant used, the carbon dioxide gas is not only inherently at a low temperature when pass.ng through the insulation 21, but in addi'- tion it is dry and therefore has a relatively low specific heat. It displaces the moisture laden air originally existing in the insulation.

The appreciable quantity of icesurrounding the refrigeration chambers and the container 1' not only acts as a heat insulator, but in addition functions as a cold storage so that in the event the supply of carbon dioxide becomes depleted, a conditioned refrigerant is available from the ice.

It is to be understood that whenever reference has been made to ice, other freezable liquids are also contemplated. Furthermore, the arrangement of refrigeration chambers, coils and other details of construction may be materially altered without departing from the invention, the form of apparatus shown in the drawings being merely illustrative of one type of device. Moreover, it is not necessary that the specific form of gasifiable refrigerant be employed in conjunction with refrigeration chambers which include wall spaces filled with a freezable liquid. A mechanical refrigeration unit could be substituted for the container for gasifiable refrigerants in a refrigerator of the type shown in Figs..3 and 4 and merely the freezable liquid surrounding the refrigeration chambers utilized.

Figs. 5 and 6 relate to a refrigeration control unit embodying the invention, this refrigeration control unit being particularly adapted for use in cold storage houses, refrigerated box cars used 110 for the shipment of perishables, etc. As there shown, the refrigeration control unit may comprise a heat insulated housing 55 which may advantageously be mounted on castors 56. Within said housing one or more expansible casings 57 115 may be positioned, said casings being preferably spaced from the interior walls of the housing 55. Within the casing 57 containers 58 for the gasifiable refrigerant are positioned, the space between the containers 58 and the casings 57 being 120 filled with a freezable liquid extending upwardly so as to contact with capping members-59. Such capping members may be provided with a heating means. The housing 55 may also be provided with a motor means such as, for example, the turbine wheel 60. A conduit 61.is provided for conveying vaporized refrigerant from the container 58 to the turbine 60. A suitable pressure regulating valve 62 is preferably positioned in the conduit 61. The valve 62 may be a thermostatic valve. The gases partially expanded in the motor 60 are discharged into expansion conduits surrounding the containers 58 and casings 5'7.

For example, the gases expanded in the motor 60 may be discharged as by means 63 into the

expansion conduits

64, 65 and 66. The expanded gases may then be discharged from the housing 55 through apertures or conduits 67. These gases may be discharged directly into the room or refrigerator 'car in which the unit is positioned, or they may be-discha'rged into operative relation with a fan 68 adapted to mix the gases with air and circulate the mixture within the enclosure to be cooled. The fan 68 may advantageously'be driven by the motor 60, thereby utilizing the expansive force of the refrigerant not only in creating a reduced temperature, but also furnishing power for circulating the refrigerant and mixing the same with air within the enclosure being cooled.

Means may be provided, such-as

valved conduits

69 and 70,.foradmitting or discharging liquid from between the casings'7 and the container 58. Furthermore, valved gas conduit means 71 may be provided for liberating pressure from within the containers 58 whenever it is desired to refill said containers with additional solidified or liquefied refrigerant.

Refrigeration control units of the type described hereinabove and illustrated in Figs. 5 and'fi, employ the heat absorbing capacity of the,

gasifiable refrigerants most efiectively. It is to be noted that the heat absorbing capacity of the refrigerants is utilized in .creating a desirable pressure within the containers 58 in forming a body of secondary refrigerant such as ice, which seals said containers and insulates them against heat transfer, in generating power and in cooling. an enclosure. Solidifled or liquefied carbon dioxide is particularly adapted for use in devices of this type as, for example, in maintaining controlled temperatures in passenger compartments of railway cars or steamships, or in the refrigeration of ship compartments or railway .cars containing perishables, as the carbon dioxide not only acts as a refrigerant, but in addition exerts a preservative effect.

Having thus fully described the invention and a number of its modifications, it is to be understood that the invention is not limited to the specific embodiments described hereinabove but an enclosure to be cooled.

instead includes all such changes, modifications, uses and adaptations as come within the scope of the appended claims.

I claim:

1. A refrigeration control unit, comprising a heat insulated housing provided with a container for gasifiable refrigerants, a body of freezable liquid substantially enclosing said container, 8. motor means, conduit means connecting said container with said motor means, a pressure control valve in said conduit, gas expansion conduits in close proximity to said body of freezable liquid,

means for conveying partially expanded gas from said motor means to said expansion conduits; a

fan operably connected to said motor means, means for directing gas from said expansion conduits to said fan, said fan being adapted to mix expanded gas from said motor means with air and circulate the mixture within an enclosure to be cooled.

2. A refrigeration control unit comprising a heat insulated housing provided with a container for gasifiable refrigerants, a body of freezable liquid substantially enclosing said container, a

- motor means, conduit means connecting said container with said motor means, gas expansion conduits in close proximity to said body of freezable liquid, means for conveying partially expanded gas from said motormeans to'said expansion conduits; a fan, and means for directing gas from said expansion conduits to said fan, saidfan being adapted to mix said expanded gas from said motor means with air and circulate the mixture within 3. A refrigeration'control unit, comprising a container for gasifiable refrigerants, a body of freezable liquid substantially enclosing said container,.a motor means, conduit means connecting said container with said motor means, gas expansion conduits in close" proximity to said body of freezable liquid, means for conveying partially expanded gas from said motor means to said expansion conduits; and a fan, said fan being adapted to mix expanded gas from said motor means motor means with air and circulate the mixture with air and circulate the mixture within an enclosure to'be cooled.

,4. A refrigeration control unit, comprising a heat insulated housing providedwith a container for gasifiable refrigerants a body of freezable liquid substantially enclosing said container, a motor means, conduit means connecting said container with said motormeans, gas expansion conduits in close proximity to said body of freezable liquid, means for conveying partially expanded gas from said motor means to said expansion conduits, and gas discharge means from said expansion conduits.

5. A refrigeration control unit, comprising a storage container for gasifiable refrigerants, gas expansion conduits in heat exchange relation to said container, conduit means connecting said container with said expansion conduits, a pressure control valve in said conduit means adjacent said container, a motor means, conduit means connecting said expansion conduits with said motor means, and a fan operably connected to said motor means, said fan being adapted to mix gas expanded in said motor means with air and circulate the mixture within an enclosure to be cooled.

6. A refrigeration control unit, comprising a storage container for gasifiable refrigerants, gas expansion conduits in heat exchange relation to said container, conduit means connecting said container with said expansion conduits, a motor means, conduit means connecting said expansion conduits with saidmotor means, and a fan, said fan being adapted to mix gas expanded in said within an enclosure to be cooled.

'7. A refrigeration .control unit, comprising a heat insulated housing provided with'a storage container for gasifiable refrigerants, gas expansion conduits, a body of freezable liquid substantially enclosing said container and between said container and expansion conduits, conduit means connecting said container with said expansion conduits, a motor means; conduit means connecting said expansion conduits with said motor means, and a fan, said fan being adapted to mix gas expanded in said motor means with air and circulate the mixture within an enclosure to be cooled.

8. A refrigeration control unit, comprising a heat insulated housing provided with a storage container for gasifiable refrigerants, gas expansion conduits, a body of freezable liquid substantially enclosing said container and between said container and expansion conduits, conduit means connecting said container-with said expansion conduits, and a pressure control valve in said conduit means adjacent said container.

9. A refrigeration control unit, comprising a. heat insulated housing provided with a container for gasiflable refrigerants, gas expansion conduits in heat exchange relation to said container, conduit means connecting said container with said expansion conduits, a motor means, and conduit means connecting said expansion conduits with said motor means.

10. A refrigeration control unit, comprising a storage container for gasifiable refrigerants, a bodyof freezable liquid substantially enclosing said container, gas expansion conduits in close proximity to said body of freezable liquid, conduit means connecting said container with said expansion conduits, a pressure control valve in said conduit means, and a gas discharge means from said expansion conduits.

11. A refrigeration control unit, comprising a heat insulated housing provided with-a storage container forgasifiable refrigerants, a body of freezable liquid substantially enclosing said 'container, gas expansion conduits in close proximity to said body of freezable liquid, conduit means connecting said container with said expansion conduits, a pressure control valve in said conduit means, and a gas discharge means from said expansion conduits.

12. A refrigeration control unit, comprising a storage container for gasifiable refrigerants, said container being provided with an inlet, a cap member over said inlet, a body of freezable liquid substantially enclosing said container and in contact with said container and cap member, gas expansion conduits in close proximity to said body of freezable liquid, conduit means connecting said container with said expansion conduits, and gas discharge means from said expansion conduits.

13. A refrigeration unit, comprising a storage container for gasifiable refrigerants, a body of freezable liquid substantially enclosing said container, gas expansion conduits, conduit means connecting said container with said expansion conduits, a pressure control valve in said conduit means, and gas discharge means from said expansion conduits.

14. A refrigeration unit, comprising a container for gasifiable refrigerants, a body of freezable liquid substantially enclosing said container, a motor means, conduitmeans connecting said container with said motor means, gas expansion conduits, and means for conveying partially expanded gas from said motor means to said expansion conduits.

15. A refrigeration unit, comprising a storage container for gasifiable refrigerants, a body of freezable liquid substantially enclosing said container, gas expansion conduits, conduit means connecting said container with said expansion conduits, a thermostatically controlled valve in said conduit means, and a discharge means from said expansion conduits.

16. In a refrigerator, the combination of a heat insulated housing, a storage container for gasifiable refrigerants, refrigeration compartments in said housing, expansion conduits for a gasified refrigerant in said housing and in heat absorbing relation to said refrigeration compartments and storage container, an admission conduit connecting said expansion conduits with said storage container, a body of frozen liquid between said housing and refrigeration compartments, and a thermostatically controlled pressure valve in said admission conduit, said thermostatically controlled valve being adapted to regulate the flow.

of gasified refrigerant from said storage container into said expansion conduits to keep said body of liquid frozen.

17. In a method of refrigeration, the steps of gasifying a gasiflable refrigerant in a limited storage chamber, expanding said refrigerant to form a heat insulating body around said cham- .ber, passing the partially expanded refrigerant through a motor, mixing the expanded refriger ant with air, and circulating the mixture within an enclosure to be cooled.

-18. In a method of maintaining gasifiable refrige'rants below a predetermined maximum pressure, the steps of storing a gasifiable refrigerant in a storage chamber sealed with a freezable medium, and regulating the maximum pressure within said chamber by varying the freezing temperature of thesealing medium.

19. In' a method of refrigeration, the steps of gasifying a 'gasifiable refrigerant in a limited chamber, partially expanding said refrigerant to freeze a liquid around said limited chamber, further expanding said refrigerant for refrigerating purposes in operative relation to refrigerating chambers, then passing the partially expanded refrigerant through a motor, mixing the expanded refrigerant with air, and circulating the mixture within an enclosure to be cooled.

20. In a method of refrigeration, the steps of gasifying a gasifiable refrigerant ina storage chamber provided with-a removable seal, and restricting the escape of the gasified refrigerant from said chamber by freezing a liquid between said seal and chamber.

21. In a method of refrigeration, the steps of gasifying a gasifiable refrigerant in a storage chamber, expanding said refrigerant to refrigerate a chamber which it is desired to maintain at a low temperature, passing the partially expanded refrigerant through a motor, mixing the expanded refrigerant with air, and circulating the mixture within an enclosure other than said chamber to cool said enclosure.

22. A refrigeration control unit, comprising a storage container for gasifiable refrigerants, said container being provided with an inlet and a cap 195 member over said inlet, a body of freezable liquidin contact with said container and cap member, gas expansion conduits, conduit means connecting said container with said conduits, a motor means, conduit means connecting said expansion conduits with said motor means, and a fan, said fan being adapted to mix gas expanded in said motor means with air and circulate the mixture within an enclosure to be cooled.

23. A refrigeration control unit, comprising a 15 housing containing a storage container for gasifiable refrigerants, said container being provided with an inlet and a cap member over said inlet,

a body of freezable liquid in contact with said container and cap member, gas expansion conduits, conduit means connecting said container with said expansion conduits, and a pressure control valve in said conduit means adjacent said container.

24. A refrigeration control unit, comprising ahousing provided with a container for gasifiable refrigerants, said container beingprovided with an inlet and a cap member over said inlet, a body of freezable liquid in contact with said container and cap member, gas expansion conduits within said housing, conduit means connecting said container with said expansion conduits, a motor means, and conduit means connectingsaid expansion conduits with said motor means.

25. A refrigeration control unit, comprising a 35 housing provided with a container for gasifiable refrigerants, said container being provided with an inlet and a cap member over said inlet, a body of freezable liquid in contact with said container 'and cap member, a motor means, conduit means