US2101656A

US2101656A - Refrigerating machine

Info

Publication number: US2101656A
Application number: US2912A
Authority: US
Inventors: Steenstrup Christian
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1935-01-22
Filing date: 1935-01-22
Publication date: 1937-12-07
Anticipated expiration: 1954-12-07

Description

Dec. 7, 1937. g STEENSTRUP I 4 2,101,656 I REFRIGERATING MACHINE Filed Jan. 22, 1955 2 Sheets-Sheet l I Inventory ChHstiah Ste'enstrmp,

is Attbr-ney Dec. 7, 1937. C.STE:NS RUP 1 2,101,656

I REFRIGERATING MACHINE Filed Jan. 2,2, 193s 2 Sheets- 8116912 Inventom Christian Steenstrup,

His AttOF'neld.

Yawn De f 1,1937

UNITED STATES was.

PATENT- OFFICE aamrcnaa'rma momma Christian Steenstrup, Schenectady, N. 'r., as-

signor to General Electric Company, a corporation of New York Application January 22, loss, Serial No. 2.912

18 Claims. (01. 62-99) My invention relates to refrigerating machines.

/ In many types of refrigerating machines and particularly in those designed for domestic use,

it is necessary to make provision for the storage 6 and preservation of alarge variety of perishable articles and it is also desirable to provide appa ratus for freezing ice and the like therein. Some perishable articles, such as me at, which are to be stored for a relatively long period of time can 10 be most easily preserved by maintaining them at a temperature below 32F. Other articles, such as milk, should be maintained at a somewhat.

higher temperature. In addition, it is necessary to make provision for the storage of vegetables of various kinds, which also need' not be kept at' a temperature below 32" F., but which aresubject to rapid deterioration through dehydration unless kept under proper conditions of temperature and humidity. .In commercial cold storage establishments it is possible to provide a large number of separate refrigerating machines, each being designed to maintain the particular temperature and humidity conditions required by the particular variety of articles tobe preserved therein. It is obvious, however, that such an arrangement is not economically feasible for domestic use or for use in small restaurants, and the like.

erating device and that the entire apparatus be preferably housed in a single cabinet.

Refrigerating machines of the primary-sec ondary type are particularly. adapted for the purpose described. In refrigerating machines of the primary-secondary type a primary refrigerant syst'em o'r circuit is provided which includes a primary evaporator supplied with liquid refrigerant from a suitable source or refrigerant 4o circulating device of any. of the wellknown types.

The secondary refrigerant system or circuit also includes an evaporator.- Ifhe refrigerant pass sages of the two refrigerant circuits are not in communication with each other, but "portions of 1 the two refrigerant-circuits are, however, ar-

ranged in heat exchanged relationship. so. that the primary evaporator abstracts heat. from the refrigerant contained in the secondary refrigerant circuit. Because of the independence of the circulatory systems of the two refrigerant cir--.

cuits it is possible to maintain the evaporator contained-in each'circuit at a different temperature from the other. i x

It is an object of my invention to provide a- 6 refrigerating machinehavin'g a single refrigerant Limitations of space'and cost make it necessary that the refrigerating apparatus for in- 3o stallations of this type contain but a. single refrigscription proceeds and the features of novelty which characterize my invention will be pointed outwith particularity in the claims annexed to 15 .and forming a part of this specification.

For a better understanding of my invention reference may be had to the accompanying drawings, in which Fig. 1 is a front elevation partly in section -of a refriger lng machine embodying 20 my invention; Fig. 2 is side elevation partly in section of the refrigerating machine shown in Fig. 1.; Fig. 3 is an exploded view of the refrigerating machine shown in Fig. 1 the lower portion thereof being partly cut away; and Fig.1! is a sectional detail view of a modified form of heat conducting member which maybe used in the refrigerating machine shown-in Figs. 1, 2, and 3. Referring to the drawings,' in Fig. 1 I have shown ja refrig'erating machine embodying my 30 invention having a smooth walled rectangular cabinet made up of separable upper and lower portions l 'andZ, respectively.. The upper por- -tion I of'the cabinet is provided with an outer sheet metal shell 3 and has a rectangular food storage or freezing compartment 4 formed therein. The side wallsand top of the freezing compartment 4 are surrounded by heat insulation ii.

- 'I'he lower portion 2 of the cabinet, which sup ports the upper portion: I, is provided with an. 40

outer sheetmetal shell'B, and has a rectangular food storage or cooling compartment I formed therein. The side walls and bottom wall of 'the compartment I are surrounded by heat 'ins'ula tion- 8. The metal shell 3 is provided with a 5 downwardly extending rectangular flange Ia,

which surrounds the upper periphery of the metal I shell 6,}thereby forming aflrm telescopic Joint between the" upper and lower portions I and 2 respectivelyf'of the cabinet, and effectively pre- 50 vents theirrelative lateral displacement. A rectangular rubber gasket 9 rests on the inturned. rectangular upper edge of the metal shell 8 and is firmly pressed thereon by the weight of the upper portion l of the cabinet. An air-tight so joint is thus formed between the upper and lower portions of the cabinet and in that way the ingress of air to the .space between them is. prevented. It is necessary thus to exclude moistureladen-air from the space between the walls of the cabinet containing insulation both to prevent the formation of frost therein and also to prevent the deposit of moisture in the insulation, because the insulation is usually made of some dry fibrous material, the heat insulating properties of whicha're radicallyreduced when it absorbs a substantial amount of moisture.

' The freezing compartment 4 is provided with a metallic liner ll cooperating with a corrugated metal sheet 12, which surrounds the liner II on four sides thereof to form a refrigerant,evaporator Ill associated with the freezing compartment 4.. The inwardly projecting ridges of the corrugations formed in the sheet I2 are in contact with the smooth sheet metal liner Ii and are welded; brazed or otherwise secured thereto throughout their length. The transverse corrugations in.the plate i2 cooperate with the liner II to form refrigerant passages l3 which are connected at their opposite ends with a header M, the latter being formed by opposed portions of the liner l I and the metal sheet l2.

An evaporator structure consisting of a smooth cooled by natural draft. I Liquefied refrigerant leaves the condenser I! through a conduit I8 and passes through a flow controlling float valve l9 flowing therefrom through a conduit 20 to an inlet 2l in the side of the evaporator Ill. The

liquid refrigerantis thus injected into the evaporator lll by'the inlet 2| from the conduit 20 and reclrculates through the refrigerant passages l3 of the evaporator l0 and its header l4. Liquid refrigerant in the refrigerant passages I3 is vaporized by the absorption of heat from articles contained in the freezing compartment 4 and the upper wall of the lower compartment I and the bubbles of vaporized refrigerant flow therej through to the header [4 where they are collected above the level of the liquid refrigerant therein. The vaporized refrigerant collected in the header I4 is returnedto the compressor in. the casing l5 through a suction line 22, which is connected to the top of header l4 and above. the level of the liquid refrigerant therein.

The cooling compartment 1 has a metallic liner 26, which is surrounded on four sides by a metal sheet '21 provided with transverse corrugations cooperating with the liner 28 to form the refrigerant passages of a secondary evaporator or container 25 associated with the cooling compart- -ment I and constituting a secondary refrigerant system. The inwardly extending ridges of contact with the smooth sheet metal liner 26 and are welded, brazed or otherwise secured thereto throughout their length. A body of liquid vaporizable refrigerant is contained in the secondary side portions thereof, and as it absorbs .heat

from articles contained in the cooling compartment I it is vaporized, the bubbles of vaporized refrigerant passing upwardly through the vertical refrigerant passages of the evaporator 25 and being collected in the upper horizontal portion 28 thereof. d

The top of the secondary evaporator 25 and the bottom of the primary evaporator ID are arranged adjacent the opening in the interior of the refrigerator cabinet between the freezing compartment 4 and the cooling compartment 1 and a corrugated resilient metal plate 29 is placed between the top of the secondary evaporator 25 and the bottom of the primary evaporator I0, which plate together with the top of the secondary evaporator 25 and the bottom of the primary evaporator l0 form a dividing wall between the freezing compartment 4 and the cooling compartment I. The corrugated metal plate 29 thus forms a resilient heat conducting member between the primary and secondary evap'orators to facilitate heat exchange between the two refrigerant circuits.

As best shown in Fig. 3, the corrugations in the metal plate are arranged transversely of the parallel corrugations in sheets l2 and 21 in order to improve the contact between adjacent surfaces thereof. The clearance between the sheets 12 and 21 is made slightly less than the unstressed depth of the corrugations in the metal plate 29, so that when the respective parts are in position the metal plate 29 will be somewhat flattened, accordion fashion, thus insuring a tight contact between the abutting surfaces of sheets I2 and 21 and the metal plate 29. I have also found it advantageous to cover these abutting surfaces with a thin film of grease which improves the contact and aids in preventing the formation of frost therebetween.

ator 25 is liquefied and then drains back to the lower portion thereof where it again absorbs heat from articles stored in the cooling compartment and is vaporized. As best shown'inFigs. 1 and 3, the top portion of evaporator 25 slopes to one side so as to facilitate the return flow of liquid refrigerant therefrom to the lower portion of the evaporator.

The heat conductivity of the plate 29 is pro- I portioned by varying its constituent material, the

temperature of the primary evaporator It be substantially lower than that of the secondary evaporator 25 for the proper operation of the machine. The'primary evaporator it should be maintained at a temperature of from 0 to 10 FJwhile the temperature of the secondary evap'- orator-25 should be maintained about 32 F.

of these evaporators with relation to the proper preservation of the materials contained in the compartments 4 and I, respectively, is pointed out. more in detail below.. The desired diflerence in temperature between the evaporators l0 and 25 may also be attained by proportioning the amount of liquid refrigerant contained in each of them. used as the-refrigerant in both evaporators, the amount of liquid refrigerant in the secondary evaporator 25 may be proportioned with respect to its total volume in such manner that only the lower portions of the refrigerant circulatory passages of the secondary evaporator 25 formed between the sheets of metal 25 and 21 are filled with liquid refrigerant. Then, since the portion of the evaporator containing liquid refrigerant performsthe. major part of: the cooling, the total amount of heat dissipated from the cooling compartment I is decreased and the averagetemperature prevailing in the cooling compartment is increased.

I have thus provided meansfor abstracting heat from the contents of both the freezifig and cooling compartments 4 and I in such manner that each is maintained at its appropriate tem- 29 described above. The resilient heat conducting member 30 comprises a body of thermally conducting masses 3i, which may. be metallic shot of spherical configuration made of lead or steel, or the like, and which are bonded together by a resilient matrix of rubber, or some similar binding material. The metallic spheres areso arranged that their adjacent peripheral portions are in direct contact thus forming a heat transfer path between the sheets i2 and 21 while the rubber matrix allows a suflicien-t resilience in the member at that its upper and lower surfaces 5 will form a tight contact with the adjacent irregular surfaces of the sheets It and It. It will be obvious to those skilled in the art that other forms of resilientheat conducting members may be substituted for the forms which I have illustrated. The ai'nountof heat transferred through the member I0 maybe limited, for the purposes noted above, by varying the number of thermally conducting masses 3| and the distance between this upper portion I of the cabinet 'may be easily attached and removed from the lower portion 2 for purposes of sssembiyand repair. The separable arrangement of the upper and lower portions l and 2'01' the cabinet and-the corrugated 'plate 29 is best shown'in'Fig. 3. The secondary evaporator 25 isarranged to be-easiiy inserted or removed through the opening in the. top of insulatingcasing I thus further taking advantage of the separable construction of the cabinet.

As will be seen from an inspection of Fig. 2, the" freezing and cooling compartments 4 and I are If sulphur dioxide, for example, is

and I have found- 40 tively, in the front walls thereof which may be closed by thedoors 34 and 3 5. The

openings

32 and 33 provide a convenient means of access to their respective compartments. Cuts of meat,

' or other perishable articles which should be maintained at a temperature of below 32 F., usually within the range of from 0 F. to 10 F., in order to 'ment 4. Trays of water to be frozen, ingredientsfor ice cream and the like, may alsobe placed in the freezing-compartment 4. The cooling compartment I is provided with horizontal shelves 36 which are supported on the projections 31 formed on the interior lateral walls of the metallic liner 26. Bottles of milk, vegetables and the like, may be preserved in the cooling compartment I at a temperature above 32 'F. and below F. F. to be a desirable average. operating temperature. It will be noted that the secondary evaporator 25 surrounds four walls of the cooling compartment I thus providing a relatively large cooling area in proportion to the cubic contents of the cooling compartment I. Thus, it is possible to cool the contents of compartment I witha relatively small temperature differential, that is in the order of about .5" F..- between the'compartment and the secondaryevaporator 25. The use of an evaporator surrounding at least four walls of the compartment I has a further advantage in maintaining a small temperature differential between the contents of the compartment and the evaporator which cools it. This advantage results from thefact that heat leaking into the compartment I through the insulated walls 8 thereof. is intercepted on at least four sides by the evaporator 25. This heat,

which leaks into the cabinet, is thus absorbed directly by the evaporatorsurfaces. In the case of a conventional type of refrigerator in which a large compartment is cooled by a relatively small and compact evaporator, heat," which leaks into the cooling compartment through the walls thereof, must be transferred through the air contained in the compartment to the evaporator thus further increasing the temperature differential between the air in the compartment and the.

evaporator. By means of the arrangement described, the interior walls of the evaporator 25 i 3 I provided with alined openings .32 and 33, respec may be maintained at a temperature above 32 F. and thus frosting of the walls of the evaporator 25 and hence dehydration of the contents of the cooling compartment I, is avoided. Dehydration of vegetables and similar articles is of prime importance to their'proper preservation, since dehydration is one of the principal causes of their wilting and taking on an unpalatable appearance. In the illustrative form of myinvention the primary evaporator I0 is also provided with a relatively large cooling area in proportion to the cubic contents of the freezing'chamber 4 in order to reduce the frosting thereof. That is, if we assume a fixed rate of dehydration, the thickness of the layer of frost formed on the evaporator lfl'will be inversely proportional to its area.

While I have shown a particular embodiment tion to be limited to the particular construction shown and described and I intend in the appended What I claim as new and desire to secure by Letters Patent of the United States is:

. of m'yjnvention inconnection with a'compression refrigerating machine, I do not desire my invenwith said cooling compartment for cooling-the l. A refrigerating machine comprising a heat insulated cooling compartment, a separable heat insulated freezing compartment mounted adjacent said cooling compartment, said compartments being mounted as a unitary structure and the exterior wall of said compartments defining a smooth walled rectangular cabinet, means including a refrigerant evaporator having a portion thereof associated with saidfreezing compartment for cooling the contents thereof to a relatively low temperature, means including a second refrigerant evaporator having a portion thereof associated means including a refrigerant evaporator having a portion thereof associated with said freezing compartment for cooling the contents thereof to a relatively low temperature, means including a second refrigerant evaporator having a' portion thereof associated with said cooling compartment for cooling the contents thereof to a temperature above freezing, and means including a portion of the first mentioned evaporator for abstracting heat from refrigerant contained in said second evaporator.

3. A refrigerating machine comprising a heat insulated cooling compartment, a separable heat insulated freezing compartment supported on the top of said cooling compartment and cooperating therewith to form a unitary cabinet structure, means including a refrigerant evaporator having a portion thereof associated with said freezing compartment for cooling the contents thereof to a relatively low temperature, said evaporator having a second portion thereof extending along the bottomof said freezing compartment, and means including a secondary refrigerating apparatus having a portion thereof associated with said cooling compartment for cooling the contents of said cooling compartment to a temperature above freezing, said secondary refrigerating apparatus having a refrigerant passage extending along the top ofsaid cooling compartment in heat exchange relationship with the adjacent portion of said first mentioned evaporator. I V

4. A refrigerating machine comprising heat insulated cooling and freezing compartments,

means including a refrigerant evaporator having a portion thereof associated with said freezing compartment for cooling the contents thereof to a relatively low temperature, said evaporator having a second portion thereof extending along the exterior side of oneof'the walls of said freezing compartment, means including a secondary "refrigerating apparatus having a portion thereof frigerating apparatus sage extending along the top of said cooling com- 5. A refrigerating machine comprising a heat insulated cooling compartment, a separable heat insulated freezing compartment mounted on top of the said cooling compartment, means including a refrigerant evaporator having a portion thereof associated with said freezing compartment for cooling the contents thereof to a relatively low temperature, said evaporator having a second portion thereof extending along the bottom of said freezing compartment, means including a secondary refrigerating apparatus having a portion thereof associated with said cooling compartment for cooling the contents of said cooling compartment to a temperature above freezing, said-secondary refrigerating apparatus having a refrigerant passage extending along the top of said cooling compartment, and means including a corrugated sheet of resilient heat conducting material for transmitting heat from said secondary refrigerant apparatus refrigerant passage to the adjacent portion of said first mentioned evaporator.

6. A refrigerating machine comprising a heat insulated cooling compartment, a separable heat insulated freezing compartment mounted on the top of said cooling compartment, means includa refrigerant evaporator having a portion thereof associated with said freezing compart ment for cooling the contents thereof to a relatively low temperature, said evaporator having a secondportion'thereof'extending along the bottom of said freezing compartment, means including a secondary refrigerating apparatus having a portion thereof associated with said cooling compartment for cooling the contents thereof to a temperature above freezing, said secondary rehaving a refrigerant passaid secondary refrigerating apparatus refrigerant passage to the adjacent portion of said first mentioned evaporator.

7. A refrigerating machine comprising separable freezing and cooling compartments mounted adjacent each other, a rectangular metallic liner forsaid freezing compartment, a refrigerant evaporator extending about at least four sides of said liner, an insulating casing surrounding said freezing compartment and having an aperture therein exposing a portion of an exterior side of said refrigerant evaporator, a rectangular metallic liner for said cooling compartment, a second refrigerant evaporator extending aboutat least four sides of said last mentioned liner, an insulating casing surrounding said cooling compartment and having an aperture therein adjacent the aperture in the first mentioned insulating casing exposing a portion of an exterior side of said secondary refrigerant evaporator, and means including a resilient heat conducting member for transmitting heatbetween the exposed portions of said evaporators.

8. A refrigerating machine comprising separable freezing and cooling compartments mounted adjacent each other, said freezing compartment having a rectangular metallic liner, a corrugated metallic sheet surrounding said liner on at least four sides, said liner and said sheet defining a refrigerant passage between the juxtaposed faces thereof, an insulating casing surrounding said freezing compartment and having an aperture therein exposing a portion of an exterior surface of said refrigerant passage, a rectangular metallic frigerant passages.

9. In a refrigerating apparatus having a primary refrigerant evaporator and a secondary refrigerant evaporator containing a body of liquid refrigerant, means for supplying liquid refrigerant to said primary evaporator and means including'a resilient heat conducting member arranged between said primary and secondary evaporators in heat exchange relationship therewith for transferring heat from the refrigerant in said secondary evaporator to the refrigerant in said primary evaporator.

, 10. In a'refrigerating apparatus having a primary refrigerant evaporator and a secondary refrigerant evaporator containing a body of liquid refrigerant, means for supplying liquid refrigerant to said primary evaporator, and means in, cluding a resilient heat conducting member comprising a body of thermally conducting masses arranged between said primary and secondary evaporators in heat exchange relationship therewith for transferring heat from the refrigerant in said secondary evaporator to the refrigerant in said primary evaporator.

11. In a refrigerating apparatus having a pri mary refrigerant evaporator and a secondary refrigerant evaporator containing a body of liquid refrigerant, means for supplying liquid refrigerant to said primary evaporator, and means including a corrugatedsheet of resilient heat conducting material arranged between said primary and secondary evaporators in heat exchange relationship therewith for transferring heat from the refrigerant in said secondary-evaporator to the refrigerant in said primary evaporator.

12. In a refrigerating apparatus having a primary refrigerant evaporator and a secondary re-' frigerant evaporator containing a body of liquid refrigerant, means for supplying liquid refrigerant to said primary evaporator, and means ineluding a resilient heat conducting member comprising a" body of metallic spheres bonded together by rubber arranged between said primary I and secondary evaporators in heat exchange relationship therewith for transferring heat from the refrigerant in said secondary evaporator to l the refrigerant in said primary evaporator.

13. A refrigerating machine comprising heat insulated freezing and cooling compartments having an opening therebetween, means including a prlmary evaporator having a portion thereof associated with said freezing compartment for cooling the contents thereof to a relatively low temperature, said. primary evaporator having a further portion thereof extending across said open .ing, means including a secondary refrigerating apparatus provided with a secondary evaporator having a portion of relatively large area associated with said cooling compartment for cooling the contents of said cooling compartment to a 4 temperature above freezing and for maintaining a relatively small differential in temperature be 75 tween said secondary evaporator and the contents of said cooling compartment to prevent dehydration thereof', said secondary refrigerating apparatus also including a refrigerant passage in heat exchange relationship with the portion of said primary evaporator extending across said opening between said compartments.

14. A refrigerating machine comprising a heat insulated cooling compartment, a separable heat insulated freezing compartment supported on top "of said cooling compartment and cooperating therewith to form a unitary cabinet structure, means including a refrigerant evaporator having .a portion thereof associated with said freezing compartment for cooling the contents thereof to a relatively low temperature, said evaporator hav ing a second portion thereof extending along the bottom of said freezing compartment, means including a secondary refrigerating apparatus having a portion thereof associated with said cooling compartment for cooling the contents of said cooling compartment to a temperature above freezing, said secondary refrigerating apparatus having a refrigerant passage extending along the top of said cooling compartment, and means transferring alimited amount of heat from said secondary evaporator to said primary evaporator for maintaining said secondary evaporator at a relatively higher temperature than said primary evaporator.

15. A refrigerating machine comprising a heat insulated cooling, compartment and a heat insulated freezing compartment, said compartments being mounted in separable superposed relationship yvith the exterior vertical walls thereof arranged in alignment, means including a peripheral flange extending about the edge of one of said compartments adjacent the other of said compartments .for preventing lateral displacement between said compartments, means including a refrigerantevaporator having a portion thereof associated with said freezing compartment for cooling the, contents thereof to a relatively low temperature, means including a second refrigerant evaporator having a portion thereof associated with said cooling compartment for cooling the contents thereof to' a temperature above freezing, and means including a portion of the first mentioned evaporator for abstracting heat from refrigerant contained in said second evaporator.

16. A refrigerator comprising a heat insulated 'cablnet means for dividing the interior of said cabinet into a plurality of food storage compartments to be cooled to different temperatures, means including a primary refrigerating system for cooling one of said compartments to a relatively low temperature, means including a secondary refrigerating system for cooling the other of said compartments to a relatively higher temperature, and means including a portion of said I primary refrigerating system and a portion of said secondary refrigerating system arranged in heat exchange relationship and forming at least a portion of said dividing means for transferring heat from said secondary refrigerating system to said primary refrigei ating system.

17. A refrigerator comprising a heat insulated cabinet, means for dividing the interior of said cabinet into a plurality of food storage compartments to be cooled to different temperatures, means including a primary refrigerating system for cooling one of said. compartments to a relatively low temperature, means including a secondary refrigerating system for cooling the other of said compartments to a relatively'higher temperature, and means including a portion of said primary refrigerating system forming at least a portion of said dividing means for transferring heat from said secondary refrigerating system to 5 said primary refrigerating system.

18. A refrigerator comprising a heat insulated cabinet, means for dividing the interior of said cabinet into a plurality of food storage compartments to be cooled to different temperatures,

10 means including a primary refrigerating system for cooling one of said compartments to a relatively low temperature, means including a secondary refrigerating system for cooling the other of aid compartments to a relatively higher temper lture, and means including a portion of said secondary refrigerating system forming at least a portion of said dividing means for transferring heat from said secondary refrigerating system to said primary refrigerating system.

CHRISTIAN STEENSTRUP.