US2065985A - Method and apparatus for refrigeration - Google Patents

Description

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E. RICE. JR

METHOD AND APPARATUS FOR REFRIGERATION 10 Sheets-Sheet l Filed July 5, 1936 Dec. 29, 1936. E. RICE, JR

METHOD AND APPARATUS FOR `REFR'.[C'i'lll'lION Fiied July 5 1936 10 Sheets-Shet 2 R J E m R E METHOD AND APPARATUS FOR REFRIGERATION 1o sheets-sheet 3 Filed July 3, 1936 SWW/M Edward Annina@ @am fw Dm. 29, i936. E. RncE, JR

METHOD AND APPARATUS FOR REFRIGERATION' l0 Sheets-Sheet 4 Filed July 5, 1936 121 1 id! in Lava Dec. 29, 1936. E. RICE. JR

METHOD AND APPARATUS FOR REFRIGERATION l0 Sheets-Sheet 5 Filed July 3, 1956 Dec. 29, 1936. E. RICE. JR 2,065,985

METHOD AND APPARATUS FOR REFRIGERATION Filed July s, 1936 1o sheets-sheet e 717m. 2] l l y 745 `.222

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Dec. 2 9, 1936. E. RICE. JR

METHOD AND APPARATUS FOR REFRIGERATION 10 Sheets-Sheet' '7 Filed July 3, 1956 VMM Dec. 29, 1936. E. RICE. JR Y METHOD AND APPARATUS FOR REFRIGERATION Filed July 3, 1936 10 Sheets-Sheet B www Uma Dec. 29, 193.6.

E. RlcEvJR METHOD AND APPARATUS FOR lREFRIGE'BATION V Filed July 3, 1936 10 Sheets-Sheet 9 award fue@ 10 Sheets-Sheet 10 @MWA Dec. 29, 1.936.a E. RICE, JR y METHOD AND APARATUS FOR REFRIGERATIONv Filed July 3, 1936 .I llllllll |I|||I llllllllllllllll IIJ 'www MMM.

Patented Dec. 29, 1.936 Y UNITED STATES lPmiralr'r OFFICE RIETHOD AND APPARATUS IFR REFRIGERATION Edward Rice, Jr., New York, N. Y., assignor t Internationalv Carbonio, Inc., New York, N. Y., a corporation of Delaware Application July 3, 1936, Serial No. 88,876

18 Claims.

This invention relates to improvements in methods and means for refrigerating by use of solid refrigerants, such as water ice' (solid H2O) and carbon dioxide ice (solid CO2).

5 A principal object of the invention is to provide of the volume of the refrigerant, and to this lattery end, the invention contemplates the'provision of a method for materially increasing the refrigerating efliciency of relatively small quantities of a solid refrigerant.

A More specically, an important object of the invention is the provision of a method of refrigeration by the use of a solid refrigerant which will produce effective refrigerating temperatures i in the refrigerating chamber more closely approximating the melting or subliming temperature of the ice than the heretofore known methods, and which will maintain such temperatures even when the mass of` ice has been reduced to relatively small dimensions.

. Still another object 'of the invention is the provision of a method of refrigerating by use of solid` refrigerants which will permit a rapid acceleration in the rate of ice meltage or sublimation irrespective of the volume of the refrigerant when the temperatures in the refrigerated area are increased.

VA still further-object of theinvention is to provide a method of refrigeration by means of a solid refrigerant which will permit the refrigeration of practically any desired space whether occupied with a' gas (including air), liquid, solid or a comv blnation thereof without actual contact of the refrigerant with the contents of the space whereby when required .the refrigerant may be entirely di` vorced from the refrigerated area.'

still further object of the invention is the provision of refrigerating apparatus -for use with a solid refrigerant in which the principal heat transfer tothe refrigerant takes place from the refrigerated space or mass to a conductorof high thermal conductivity and extended surface, and thence conductively to a relatively small surface of the refrigerant through a section of the conductor suiciently large to transmit the required effective refrigerating temperature.

amount of heat for maintaining a predetermined v (ci. sar-s1) The invention further contemplates the provision of refrigerating apparatus for use interchangeably with solid CO2, solid H2O or other solid refrigerannin which the principal heat transfer I to the solid refrigerant takes place from the :re-V 5 frigerated area or mass to a conductor of high thermal conductivity and extended surface,

- thence conductively tov a relatively small surface of the refrigerant through a section of the conductor of sumcient sizeto transmit anamcunt 10 of heat required for maintaining a predetermined effective refrigerating temperature and in which differences in the melting or subliming temperatures of the different refrigerants may be compensated by means of variable conductory resist- 15 ances placed between the conductor and the refrigerant.` .y Still more specifically, as regards the use of solid H2O and similar solid refrigerants of relatively high melting point, an object of the inven- 50 tion is to provide a novel method of refrigeration vwhich will produce effective refrigerating'temperatures more closely approximating the melting temperature of the ice than has heretofore been possible, and vwill maintain such temperatures gg even after the volume of the ice has been reduced to relatively small amounts.

Again specifically, and as regards the use of solid refrigerants, such as solid CO2. having a relatively low melting-point or point of sublima- .n tion, another object of the inventionis to provide a method of refrigerating with such refrigerante which shall be both highly eiiicient and capable of close and accurate regulation of the effective refrigerating temperatures, said temperatures be- 35 ing maintainableeven when the volumeof the refrigerant has been reduced to relatively A,small amounts.

A further and more specific object of the invention is the provision4 of a method of refrigeration n by the use of carbon'dicxideiceor the like which will permit the automatic maintenance .of an approximately constant temperature in the refrigerating chamber under varying conditions of outside atmospheric temperature, of contentiof refrigerating chambenand of .ice supply.

A further object of the. invention is the provision of refrigerating apparatus for use with C02, ice" or the. likev in which the principal heat transfer from the refrigerating chamber and its -contents to the "ic e takes place convectively from the chamber to a conductor of high thermal conductivity, thence 'conductively to the ice, and in which means may be provided for regulating:1 the convection currents in such a' manner 56 that an approximately constant temperature may be maintained in the refrigerating chamber.

A further object of the invention is to provide a method of and apparatus for refrigerating by the use of CO2 "ice or the like whereby an initial rapid chilling of the refrigerating chamber or the contents may be had when desirable by a comparatively rapid melting or sublimation of the ice, and thereafter the required temperature maintained by a much slower sublimation of the (licei,

A further object of the invention is the production of a refrigerating unit ofv such character that it may be employed either in household and stationary refrigerators or in the refrigeration of railway cars, motor truck bodies, or other transportation units.

Still another object of the invention is to provide simple and relatively inexpensive refrigerating units of a character adapted for use in household and other refrigerators employing solid H30 whereby my invention may be readily available for that classof refrigeration.

A sun further object or the invention 1s thev provision of a refrigerating apparatus in which heat may be absorbed from an upper portion of the space to be cooled and conducted downwardly through an all-metallic path of heat transfer to a solid refrigerant positioned at a lower level.

The invention further resides in 'certain novel and advantageous structural features and details and in specific embodiments representing various applications thereof to different classes of refrigeration, all as'hereinafter set forth and illustrated in theattached drawings, in which:

Fig. 1 is a diagrammatic sectional view illustrating the embodiment of my invention as applied to household refrigerators and similar classes of refrigerators.

Fig. 2 is a diagrammatic sectional view illustrating another embodiment of my invention.

Fig. 3 is a section on line 3-3 of Fig. 2.

Fig. 4 is a diagrammatic sectional view illustrating a further embodiment of my invention.

Fig. 5 is a diagrammatic sectional view illustrating the application of the principles of my invention to the construction of a containerfor frozen products such as icecream.

Fig. 6 is a section on line 8-8 of Fig. 5.

Fig. 7 is a diagrammatic sectional view illusvtrating a modification of the embodiment of the invention illustrated in Fig. 5.

Fig. 8 is a section on line 8--8 of Fig. 7.

Fig. 9 shows another form of refrigerator storage cabinet embodying'my invention.

Fig. 10 is a section on line IU-Ill of Fig. 9.

Fig. 11 is a vertical sectional view showing a vformv of sectional chamber 'container made in accordance with my invention.

Fig. 12 is a section on line I2-I2 of Fig. 11.

vFigs. 13 'and 14 are vertical .sectional views illustrating my invention as embodied in rela- Fig. 19 is a vertical sectional view of another form of refrigerator embodying my invention.

Fig. 23 is a horizontal sectional view of a fur- A.

ther modied form of the invention taken on line 23-23 of Fig. 24.

Fig. 24 is a vertical sectional view on line 24-24 of Fig. v23.

Fig. 25 is a front elevation of a household refrigerator constructed in accordance with my invention and adapted also for making water-ice cubes and storage of frozen products.

Fig. 26 is a horizontal sectional view on line 26-26 of Fig. 27.

Fig. 27 is a vertical-sectional view on 21 of Fig. 26.

Fig.. 28 is a horizontal sectional view on line 2l-2l o f Fig. 29, illustrating a modification of the structure shown in Figs. 25 to 27, to produce a circular refrigerator having rotating shelves.

Fig. 29 is a section on line 29429 of Fig. 28; Fig. 30 is a fragmentary vertical sectional view illustrating a modification of the invention comline 21- bining a structure similar to that mustrated 1n when the refrigerator is to contain ice cream and the like, the same being taken on line 3i-3l of Fig; 32. l n

Fig. 32 is a horizontal lsectional view on line 32-32 of Fig. 31 and showing the manner in which the extended heat-absorbing surfaces surv round the4 upper 'portion of the space to containthe material to be refrigerated.

' Fig. 33 is a perspective view of the metallic I lconductor plate upon which the solid refrigerant is maintained in heat-conductive relation and showing how the conductor and its extended sulffaces may be formed to the desired shape.

Fig. 34 is a vertical sectional view through a further modification of the invention in which the extended heat-absorbing surfaces extend around at -least a portion of the upper part of the space to be refrigerated, and

Fig. 35 is a horizontal sectional view of the form of refrigerator shown in Fig. 34.

. Water ice or solid H2O is more widely used than. any other form oi' refrigerant. rOne of the principal drawbacks in the prior methods of using this refrigerant or, in fact, any solid refrigerant is that although any given mass of the refrigerant, no matter how small, hasa ilxed refrigerating value; yet the smaller the mass becomes, the slower its refrigerating action becomes 'l'.his is due to the 'fact that the heat is usually either entirely or almost entirely brought to the ice convectivelyeitherby air or a liquid,

also.

and 'the amount of heat taken up by the refrigerant, other things being equal, depends directly on the amount of the effective surface con- .tact between the refrigerant and the circulating fluid. Obviously as the icemelts, the surface area becomes less and the refrigerating action slower. In the construction of refrigerating apparatus,

thisfeature, heretofore, has been given no con-f sideration, and no effort has been made to com-.-

pensate for the rapid decrease' in emciency as the refrigerant loses volume and surface area. As a the conductor can be with very indifferent or inferior results.

One reason that the mechanical household refrigerator has progressed so rapidly is because the ordinary water ice refrigerator cannot maintain satisfactory refrigeration unless it is continually serviced and kept practically full of ice at all times. For the'same reason, a large and growing eld for refrigeration of foodstuffs in motor 'transportation has avoided the use of water ice and other solid refrigerants. Practically the only method attempted to improve the eiciency of water ice as a refrigerant has been the use of salt, a method of limited application which apparently cannot be greatly extended.

I have discovered that the principal obstacles to the efficient use of Water ice and other solid refrigerante canv be largely overcome if the heat from the space or material to be refrigerated is picked up by comparatively extended surfaces of a metal heat conductor, such as copper, aluminum or iron, and transferred through a. substantial cross section of the metal conductor directly to a surface of the body of ice with which the metal conductor is either in immediate contact or in suitable conductive relation. I have found that bythis method, the ice can be melted at.

practically a constant rate, thus providing a constant eifec'tive refrigerating temperature practically independent of the lvolume of the refrigerant, and even with extremely small masses of the latter. I have found also that the refrigerant can be melted at an almost inconceivable rate when large amounts of heat are passed` over the extended metal surfaces. With a suflcient cross section of the conductorlmetal, as small as thirty square inches of contact surface -withv the refrigerant is sufllcient to melt enough water ice to keep a good household refrigerator below F. even on the top shelf in the vwarmest weather;

- and after the doors have been opened as long as three minutes, this refrigerator will return to its originallow temperature within twenty minutes or one-half hour. It is essential in the practice of my invention that the solid refrigerant be maintained in conductiverelation wltha substantial metal conductor having a suitably extended surface area in the refrigerated space.

While the invention is'of great importance in conjunction with the use of water ice, it is also of great value in the use of all other solid refrigerants, such as solid carbon dioxide and frozen brine. The apparatus embodying my invention need vary only slightly to meet the requirements of the particular'kind of refrigerant and the type of refrigeration required. If, for example, refrigerating temperatures around 35 to 45 F.

are desired and water ice is to be u'sed by reason' of its' cheapness and availability, then a relatively large amount of extended conductor or n surface will'be required because of the small ytemperature dierential between the waterice and the temperature required; while the same temperature can be secured by use of solid carbon dioxide with considerably less surface area by reason of the fact that with solid carbon dioxide chilled to almost any temperature required down to say minus 50 F., and accordingly a relatively largeA temperature differential be maintained between the conductor and the refrigerated space. Obviously -if temperatures are wanted near cr below the melting point of water ice, then some other solid refrigerant may be used with a subliming point that i at a temperature trol of refrigeration, ,erantit is desirable to transfer of heatv from the refrigerated space or sulciently low melting or the conductor can -be put4 affording the differential re'- quired to maintain the refrigeration wanted. Frozen brine may be used especially when put up in small and easily handled units in liquidtight metal containers. The heat transferred from the conductor to the solid brine the metal container, however, is not as constant vand controllable as in the direct contact of through water ice with the conductor or the contact of carbon dioxide ice with the conductor through a known amount of conducting resistance, as hereinafter more specifically set forth. However, as the frozen brine can be provided with a melting point practically anywherebetween 32 F. and considerably below zero and has now come into more common use and also is comparatively cheap, it is apparent that it will have a limited use as a solid refrigerantmeans in my method of refrigeration. Of course, frozenbrine directly A in solid-state can Abe used in the same way as water ice or carbon dioxide ice by permitting the melted brine to drain oi.

It will be understood that with this type of refriglimit so .far as feasible mass to that passing through the conductor. This can be accomplished by providing adequate insulation preventing transfer by radiation or by otherthan conduction through the selected conductor. By thus establishing a principal and practically sole path of transfer and utilizing in conjunction therewith suitable known resistances, a substantially perfect control may be obtained. This method of controlalso aiords a simple method for providing apparatus suitable for use with refrigerants such as water ice and carbon dioxide ice having widely different melting points. Thus a single refrigerating apparatus can be built that can use as a refrigerant either carbon dioxide or water ice or frozen brine, or, in fact, any solid refrigerant, and that can maintain practically anyrequired temperature under constant outside temperature conditions within the limits of the particular refrigerant used by a simple resistance interposed between the conductor and the refrigerant, and by providing in lthe same apparatus either manually or operated means to regulate the convection currents from the extended vconductor surfaces or fins, -the required temperature can be maintained irrespective of normal outside temperature variations. l

With reference to the drawings, -in which I have illustrated various specific applications of my invention to different types'and classes of refrigeration, and with particular reference to Fig. 1, the referencenumeral I indicates an outer known type and'having one of the upper corners for reception of the refrigerant. Inaccordance with the priorlpractice, refrigeration is obtained in this type ofrefrigerator by the convective action of air' currents circulatingin the space 5 to be cooled, as indicated by the arrows. The bottom of the compartment 3 is fcrmed of a metal casting 38,' preferably of aluminum and its thickness, with respect to the conductivity of the metal from which it is formed,

is such that heat will be conducted thereby to the lrefrigerant which is supported by the botfor maximum conmanipulation of a conductor` thermostaticallyand the side wall thereof ex posed to the convection currents in the space 5- a compartment 3 in p `,a rate suftlcient to vmaintain .the casting at a temperature suiliciently low t provide an eiIective refrigerating temperature in the space to be cooled, even when the refrigerant has been reduced to an exceedingly small volume, whereby it is possible to maintain adequate refrigerating temperatures with relatively infrequent servicings. l

The vertical side wall of the compartment 8 provides an extended surface for absorbing heat from the space to be cooled, and in order further to extend said surface it may be provided with flns 39 of a good heat-conducting metal, such as copper. v

The ice-supporting bottom of the casting 38 is inclined slightly towards the juncture with the upright wall, and in the angle outlets 4| are provided for elimination ofthe products of evaporation or sublimation.

The principal heat transfer in this embodiment of the invention takes place through the thin metallic ns 38, down the uprightV side of the casting to the bottom, or ice-supporting wall. In order to regulate the amount of heat conducted from the bottom wall to the solid refrigerant, a conductor resistance in the form of sheets 42 of a heat-insulating character may be interposed between the refrigerant and the-bottom wall upon which it is supported. 'I'he conductor resistance is of a predetermined value and selected to maintain a predetermined effective refrigerating temperature in the space 5. The solid refrigerant may be surrounded at its top and sides with insulation 43.

In Figs. 2 and 3, I have illustrated my invention as applied to a water cooler employing solid carbon dioxide as the refrigerating medium. In this instance, the conductor forming an essential part of the device consists of a solid aluminum or copper receptacle 55 which is embedded in solid insulation 56. A chamber 51 is provided in the insulation 56 for the water or y other liquid to be cooled. This chamber, as

shown invFig. 3, extends completely around the sides of the receptacle 55, but is spaced a suflicient distance from the said conductor to maintain `a desired temperature of the liquid for any predetermined temperature of the conductor. This temperature in turn is controlled by the thickness of a, conductor resistance 58 inter-` posed between the solid carbon dioxide ice and the bottom wall of the conductor. With an arrangement of this character, I have found it possible to, maintain substantially any desired temperature of the liquid within the container 51v by simple variation of the thickness of the conductor resistance 58 Whichmodifies the conductive relation between lthe conductor 55 and the refrigerant. It will be noted that in this instance the conductor while having the necessary vextended surface is not provided with fins, and

that further the surfaces 'of vthe conductor are not in direct contact with the lihuid to be cooled,v

but are in 'conductive relation therewith through the insulation separating the wallsvof the liquid container from the said conductor.

Fig. 4 shows a similarly constructed water cooler with the addition oi' a storage space 80 located below the bottom ofthe conductor, it

being possible to maintain this space at practically Iany required temperature by variation i the thickness oi'the insulatingmember 10 which constitutes conductor resistance between the space and the bottom of the conductor l5. A' more or lessvsimilar'fcrm' of conductor is shown in Figs. 5 and 6, which shows a cabinet provisions being made forV supporting the refrigerant upon the base between the said portions 84. as shown in Fig. 5. For this purpose, the refrigerant may be supported within a vertical metallic or other container open at the bottom to permit the ice to come into conductive relation with the base portion -83 of the conductor, from which it may be separated by a suitableconductor resistance member 65selected to afford a desired temperature within the receptacle 84 in which the refrigerated materialis stored. The entire conductor casting is surrounded by a suitable insulating casing 66, and provision is made in the form of removable cover plates 61 for affording access to the interior of the container 84.

In Figs. 7 and 8, I have illustrated a' similar ltype of. refrigerating apparatus which in addition includes storage chambers or receptacles 81 embedded in the insulating casing 86 in suitably spaced relation to the sides of the container 64, these compartments 61 being readily kept at a non-freezing temperature and being suitable for holding water or other substances, or materials at a relatively lowv but non-freezing temperature.

In Figs. 9 and 10, I show aform of refrigerating storage box convenient for use on store counters and under `similar conditions. In this instance, the storage space is surrounded on three sides and the bottom by the conductor 85, and the heat is picked up as it comes through the walls of the storage box and alsof from the contents and is conducted tothe bottom of the conductor, and thence to the refrigerant shown as blocks of solid carbon dioxide, which is separated from the conductor by the conductor resistance 86 generally used with this refrigerant. It will be noted that the chamber which holds` therefrigerant is separated from the storage chambers 81, 81, by insulation 88, and by varying the thickness or character of this insulation, this type of refrigerator can be used for a wide vainstance, the CO2 ice orv other refrigerant is l placed on the base of the conductor with the usual interposed conductor resistance 93 and heat absorbed from the compartment conducted downwardly thereto'by the metal of the receptacle 9|. A small removable shelf 84 is placed over the ice toY support the ice cream can or other materials -to be stored. A vent anordsescape of the sublimed gases or meltage.

- In each oi.' the refrigerating devices-shown in,`

Figs. 2 to 12, inclusive, heat will be absorbed by kthe extended heat-absorbing surfaces from thev chamber or 'spaces toV be cooled and conducted downwardly to that portion of the metal plate vwhich supports, and is maintained in heat-conductive relation with the solid refrigerant.

In the embodiment shown in Fig. 13, al small storage box adapted for use primarily with CO2 ice is shown. In this instance. the conductor takes open at one side, and provision is made for placing the refrigerant on the top wall of the c'onductor as illustrated, the usual conductor resist- -ance 91 being provided. Access to the refrigerating chamber is afforded through a removable cover 98 in the insulating casing 99, and access to the refrigerati'ng chamber is provided by a suitable removable cover member (not shown) located in the side'of the said casing.

Fig. 14 shows still another form of small storage box in which the conductor is in the form 'of a removable storage bin, this conductor being made preferably of copper or aluminum. Access to the storage space is afforded through a removable cover |02 in the top of the insulating casing |03, and this top portion |04 ofthe casing is also hinged at |05 to' permit the entire top to be turned back to permit removal of the conductor |0I. The refrigerant in thisinstance is supported upon a shelf |06 which is movable within the casing and which has legs |01 which projectl through openings in the bottom of the casing and rest upon the oor or other supporting surface. As the CO2 ice sublimes, the entire casing settles downwardly around the shelf |06, whereby the refrigerant is maintained in continuous conductive relation with the bottom of the conductor 0|. 'I'he usual conductor resistance |08 is interposed between the refrigerant and the bottom of the conductor.l

.In Figs. and 16, I have illustrated a large table or cabinet type of refrigerator adapted for use either with CO2 ice or water ice and in whichprovision is made for obtaining in the three separate compartments three dierent temperatures, when CO2 ice is used, or of two temperatures. when water ice is employed. This l refrigerator consists of an outer insulated casing having in the top a chamber for a refrigerator, the opposite sides and the bottom of which are constituted by a conductor ||2. The side walls of this conductor are provided with outwardly projecting ns ||3, and the vbottom wall is slightly elevated towards the center to create a tendency of the solid refrigerant to move by gravity towards the vertical n walls..

Access to this refrigerating chamber is had through a removable cover ||4. Three refrigerating chambers are provided numbered ||5, i8 and ||1, respectively, the chamber ||6 being located directly below the refrigerant chamber. Bailies |I0 in the chambers ||5 and ||1 extend vertically vand preferably in contact with the outer edges of the fins ||3 whereby a convective' circulation is set up in which the air moves downwardly between the ns and against the side walls ofthe conductor. The chamber ||6 is separated from the other chambers by insulating walls ||9, and in one or both of the, chambers'` ||5 a valve |20, which may be operated manually or automatically from a suitable thermostatic actuator, is provided for controllingthe movement of the convection cur-,rents downwardly past lthe walls and ns of the conductor. Where carbon dioxide ice is used, the refrigerant is surrounded in the refrigerating chamber yon four sides and the top by suitable insulation |2|, while the ice is separated from the bottom of the conductor by means of suitable conductor resistance, |22. The temperature in the chamber ||6 is controlled by the thickness and character of the conductor resistance, whereas the temperatures in the compartments |5 and ||1 are controlled not only by the conductor resistance.

but also by thelthickness and character of the insulation |2|, and may be still further con@ trolled by manipulation of the valve |20.

Figs. 17 and 18 illustrate a small shipping refrigerator box in which the conductor |26, which may suitably be made of copper or aluminum, vin effect lines the four walls and bottom ofthe casing |21. This form ofrefrigerator is particularly suited for use with CO2 ice, and it will' be noted thatthe usual protective insulation |28 and conductor resistance |29 are provided.

Referring to Figs. 19 and 20, numeral |.40 designates a refrigerating chamber having access doors I4| in the upper wall |42 thereof. The chamber walls are, of course, insulated in any usual or preferred manner and the upper wall |42 has formed therein an openingl |43.- Extending into the refrigerating chamber through this opening is an insulated cabinet |44 approximately gas tight having an open top closed by an access door |45. The bottom -wall |44a. of this cabinet has imposed thereon a conductor plate |46y which may be convenientlyconstructedfrom copper, aluminum or some other metal having a suitably high factor'of thermal conductivity.

The edges of this plate project through the cabinet walls and are provided with vertically-extending vanes |41 projecting upwardly along the sidewalls of the cabinet and preferably constructed 'integrally with the lplate |40. These vanes may have either a. plane surface or be transversely or longitudinally corrugated, the latter constructions providing an increased surl face for contact with convection currents.

Opposing the outer edges of the vanes are insulated walls |40 which combine with the cabinet to provide channels |49 through which convection currents may pass. The lower ends of these channels are closed by valves |50 regulated through a thermostat |5|. In the present instance, the valves are illustrated as pivotally connected to the lower wall of the cabinet at |52 and connected to the movable element |53 of the thermostat by a linkage generally designated at |54.,

From the interior of the cabinet a vent tube |55 may be led through the wall of the refrigerating chamber |40.- Thisl vent tubeA is made of metal of a high thermal conductivity, preferably copper, and includes a coil |55a disposed in chamber for contact with the convection currents of the chamber, preferably near the top of the chamber and where warm pockets" are liable to occur. The outlet of the vent tube isA placed below the inlet in-order to induce a ready ow of CO2 gas by syphoning, and is preferably equipped with a suitable regulating valve.

The interior of the cabinet is preferablysubdivided into a plurality of sections by vertically extending partitions |59 which may be constructed of insulating material.A These partitions are in the present instance illustrated as twoo inl number so that three "ice" spacesare the compartments have in the'bottoms thereof insulation |60 of a considrable thickness while' the third compartment has no insulation as sugvist lested in Figs. 1 9 and 20, or a'relatively thin insulation as suggested inFig. 24, .the ice" of this latter compartment will be sublimed more rapidly than that in the remaining compartments so that the ice of this compartmentacts as an initial chilling supply while that of the remaining compartments acts as a reserve supply. 'I'hus the ilrst mentioned VAice supply serves to rapidly reduce the temperature of the chamber when initially placed in operation or when a rapid reduction of temperature therein is necessary following an opening of the access4 doors |4|.

If, for example, goods are placed in vthe refrigerator at-their normal temperature and must 4been attained, the fice in the.v remaining compartments is held in reserve to 'maintain this temperature thus materially increasing the period over which refrigeration is possible and particularly adapting the apparatus for use in transportation of perishable goods where facilities for replenishing the ice store are poor.

When pre-cooled products are placed in the 'refrigerating chamber, then the bottoms of all of the compartments may be provided with insulation thus providing a maximum period of refrigeration for a given ice supply. By varying the extent to which the bottoms of the -compartments are insulated from conductor plate |46 a limited control of the rate of melting of the ice may be obtained and thereby a limited control of the temperature of the storage chamber and contents secured. l

A drip pan 6| is preferably disposed beneath the cabinet for the4 reception of water resulting from the defrosting of vanes |41 and the storage spaces of the refrigerating chamber are preferably separated from' the cabinet spaces by foraminous screens |62.

The principal amount of the heat used in melting, or subliming the ice is transferred by convection from the storage chamber and its contents to the vertically extending vanes |41, thence conductively to the plate "|46, thencev conductively directly, or through insulation |60 to the ice. A smaller amount of heat is transferred by conduction through the insulations of the ice cabinet and walls |48, and by internal convection currents within the ice -cabinet and the4 space` surrounding the vanes |41. Control of the temperature of the storage chamber and contents is secured in part by' varying the size and character of the conductor plate |46 and vanes |41, and of the insulations |44, |44a and |46 andthe insulated chamber walls and doors. However, actual changes in temperature in the contents of the storage chamber during reduction to a desired level, as well as climatic and artificial changes in temperature outside the storage chamber may require a further means for securing a constant temperaturev inside the chamber. 'I'his is achieved by the thermostatic or manual control of the convection currents through channels |49 and transferring more or less heat to conduction vanes |41 and plate |46. By these several means a variation of the rate of subliming or melting of the carbon-dioxide ice" of as' much as 1.000% can be attained which I believe is sufficient to accomplish the objects of this invention.

The structure of Figs. 21 and 22 is substantially identical with that of Figs. 19 and 20, with the exception of the fact that the chamber |40 has its access door |4|a mounted in the sideinsulating wa11sincludes one or more ducts |64 opening at the inner end through 1the Wall of channel |49 and having the outer end disposed adjacent to the wall of the chamber |40 or where warm pockets are likely to occur. A further slight modiflcation'of the control of the channel is employed in that the valves |50a instead` of being supported by the cabinet, as in Figs. 19 and 20, are directly supported from and secured to the movable member |53 of the thermostat. The thermostat has further `asso ciated therewith baille shields |65 which prevent chilled air, descending from the convection channels, from directly contacting thermostat |6| and thus causing too early a closing operationof the valves |50a.

The form shown in Figs. 23 and 24 is identical with the structure of Figs. 21 and 22, with the exception of the fact that conduction vanes are provided entirely about the cabinet walls and entrancev to the convection channels is largely through ducts |64a, the intake ends of which are disposed adjacent to the vertical walls of the chamber |40.

In Figs. 25, 26 and 27, I have illustrated refrigeration apparatus particularly adapted 'for household uses and embodying means for producing water ice cubes and for storing frozen products. From an inspection of Fig. 27, it will be noted that the conductor plate |46, which forms the false bottom of the cabinet, instead of being in direct contact with the insulating bottom |44a thereof is in vertical spaced relation thereto, with the result that a compartment |66 is produced therebeneath, which is conductively connected with the ice` compartment by the plate |46. This compartment |66 is accessible through a door |61 mounted in the Wall of chamber |40 and is adapted for the reception of freezing pans |66 for the formation -ofice cubes or use in freezing confections or for storing frozen products. The wall of the cabinet is preferably offset inwardly, as at |69, above the door openings, so that the body of the cabinet may be spaced from the front wall |10 oi' the chamber a sufiicient distance to permit the provision of radiation varies |41 between the cabinet and chamber walls thereabove. In this illustration, where the apparatus is intended for household use and supplies of ice are readily available, necessity for a construction permitting more than one column of ice, is eliminated and the entire supply may rest at its lower erd directly upon the plate |46, or upon portable insulation |60 as described above. The ice cube andifrozen storage compartment |66 may, however,.be conveniently combined with structures embodying severalvertical columns of ice as suggested in Fig. 30.

In Figs. 28 and 29, the construction' of Figs. 25 to 27 is modified to permit its adaptation to a circular refrigerator having rotatable shelving units |1|, the rotation of which will bring material stored therein opposite an access door i12, which door also is opposite, and gives access to the freezing chamber |66. y

It will be noted that in each of the constructions illustrated, the principal heat transfer tak- .ing place between the refrigerating chamber and the ice in cabinet luis obtained through conduction, the conducting element being subject to the action of convection currents passing through the channels provided by the walls |49- and the cabinet. Thermostatic regulation of this passage materially reduces the vspeed by which the refrigerant is convertedand enables the refrigerator to operate over a considerable period with a single lling. Since all gases resulting from reduction of the refrigerant are conducted to the exterior of the refrigerating chamber, they cannot come in contact with food or products stored ,therein to damage same in any Way. By regulating and maintaining automatically the temperature in the storage chamber either above or below 32. F. it is possible to refrigerate a large majority of products, particularly those perish' able products that may be damaged by freezing, and thus the uses for this method of refrigeration are numerous. Y Because of the self-contained nature of the apparatus and its adaptation to small units it is especially useful for transportation purposes. I

Figures 31 to 35 inclusive illustrate two kinds of storage boxes used for the preservation of perishable foods, for instance ice cream and other frozen foods, and are particularly adapted for the use of dry ice or brine ice. Fig. 31 is-a verticalhsection of an ice c ream cabinet using dry ice, in which 30H is the conventional insulated casing; 302 the storage compartment; 303 the metallic conductor formed preferably of a single sheet of copper or aluminum; 304 a mass of dry ice supported by that part of the conductor forming the 40- bottom of the ice compartment; 305 is any preferred form of conductor resistance interposed between the ice and the conductor to regulate the temperature of the extended heat absorbing surfaces of the conductor and hence the temperature of the refrigerated space. For this type of cabinet the conductor is usually'of 1A" thick aluminum or 1A," thick copper. It is more easily made if bent from a single continuous sheet, although the various `extended areas can be welded together. In doing so, however, it isI most important that the thickness of cross section is never decreased as the point of heat transfer with the ice is approached, asl this would form a bottle neck through which the passage of heat would be restricted. Also it is preferable not to make any joints in the conductor except by welding. If two parts of a copper conductor were soldered together there would be a large drop in temperature across the joint because solder is a much poorer heat conductor than copper. In this form of metallic.conductor installation it is preferable to have as large a proportion as possible of the total heat reaching the ice pass through the conductor l all the way to the bottom of the ice compartment and there be transferred to the bottom surface of the ice by direct contact, or through the controlled conductor resistance 305.

Another advantage of the form of conductor shown in Fig. 1 is that because it is disposed around the inside walls of the storage compartment it absorbs a great deal of the heat coming in through the walls before yit ever has an opportunity -to reach' the refrigerated goods; also being disposed mainly in the upper part of the refrigerated space the conductor tends to cut between the top and bottom o'f'the refrigerated space.

The large heat absorbing surfaces of the conductor as compared with the portion presented at the bottom of the ice compartment for transferring heat to the ice clearly is shown in Fig. 33.

Figs. 34 and 35 illustrate a cabinet similar to the combination shown in Fig. 31 and having the c ompartment, which in this particular form of the invention is adapted for dry ice, located in an updown to a minimum the temperature differential' per corner of the space to be refrigerated. In

these figures the reference character 306 indicates the cabinet having the ice compartment 301 locatedv in the upper right-hand corner .and the dry ice 303 is supported upon the conductor plate 309 which has a vertical plate-like extended portion 3i0 metallically joined to the edges therecf.

June 21, 1929; and a continuation-in-part of my application Serial No. 751,391, for Refrigeration, filed November 3, 1934, which in turn is a division I of my application Serial No. 679,435, flied July 7,- 1933, for Refrigeratiomnow Patent No. 1,980,089.

I claim: `1. The method of refrigerating by means of a solid refrigerantwhich comprisesmaintaining a solid refrigerant in heat-conductive relation with a lower portion of a solid metallic heat conductor, having a thickness so correlated to the heat conductivity of the metal from which it is formed and the area of its surface exposed for heat absorption, that it is capable of transferring heat to the solid refrigerant at a rate suiicient to maintain the heat-absorbing surface thereof at an eective refrigerating Itemperature, absorbing heat from a space to be refrigerated by an upper portion of said conductor, andtransferring the heat absorbed by the upper portion of the conductor downwardly through said conductor to the refrigerant at a rate sufficient to maintain an eective refrigerating temperature in said space.

2. In a refrigerating apparatus for use with solid Vfrom the space or material to be cooled at a relatively high level and for transferring Vsaid heat downwardly to the solid refrigerant at a relatively low level, said means including a solid heat conductor having a portion exposed at the high level for heat absorption from the space or material to be cooled, and anotherY portion to be maintained in continuousl heat-conductive relation with the solid refrigerant at the lower level, the thickness of said conductor being so correlated to the heat conductivity of the metal fro'm which it is formed and the area of its surface exposed 4for heat absorption as to'maintain said heat-absorbingportion at an effective refrigerating temperature lower `than that of `the space or material to be cooled.

Y 3. In a refrigerating apparatus for use with solid refrigerante, a refrigerant support comprising a generally horizontally disposed metallic heat conductor with which-the solid refrigerant is to be maintained in heat-conductive relation and extended surfaces extending to a higher level for absorbing heat from thespace to be `'cooled and conducting itdownwardly to the portion of the' 4. In a refrigerating apparatus for use with solid refrigerants,l a refrigerant support comprising a generally horizontally disposed metallic heat conductor with which the solid refrigerant is to be maintained in heat-conductive relation and extended surfaces extending to a higher level for absorbing heat from the space to be cooled and conducting it downwardly tothe portion of the conductor in contact with-the solid refrigerant,

the thickness of said conductor being so. correlated f to the heat conductivity of the metal from which 1 itis formed and the area of its surface exposed for heat absorption as to maintain said heat absorbing portions .at an effective refrigerating temperature lower than that of the space or material to be cooled, said extended heat-absorbing surfaces being in the form of a plate-like member metallically joined to the edge of the portion of the conductor upon which the refrigerant is supported.

5. In a refrigerating apparatus for use with solid refrigerants, a refrigerant support comprising a generally horizontally-disposed metallic heat conductor with which the solid refrigerant is to be maintained in heat-conductive relation and extended surfaces including ns extending to a higher level for absorbing heat from the space to be cooled and conducting it downwardly to the portion of the conductor in contact with the solid refrigerant, the thickness of said conductor being so correlated to the heat conductivity ofthe metal 4from which it is formed and the area of its surface exposed for heat absorption as to maintain said heat absorbing portions at an effective refrigerating temperature lower than that of the space or material to be cooled.

6. In a, refrigerating apparatus for use with solid refrigerants, a refrigerant support comprising a generally horizontally-disposed metallic heat conductor with which the solid refrigerant is to be maintained in heat-conductive relation and extended surfaces extending to a higher level for absorbing heat from the space to be cooled and conducting it downwardly to the portion of the conductor in contact with the solid refrigerant, the thickness of said conductor being so correlated to the heat conductivity of the metal from which it is formed and the area of its surface exposed for heat absorption as to maintain said heat absorbing portions at an effective refrigerating temperature lower than that of the space or material to be cooled, said extended surfaces at least partially inclosing the space or material to be cooled.

` '7. In a refrigerating apparatus adapted to be cooled by a solid refrigerant and haging a container for the refrigerant and a space to be cooled, a solid metallic heat conductor adjacent the bottom of the refrigerating container with which the solid refrigerant is to be maintained in heat-conductive relation, said conductor having extended heat-absorbing portions at least partially surrounding the space to be refrigerated, said surrounding heat absorbing portions. extending from an upper level downwardly to a level at least as low as said conductor and being metallically accasion joined with the edges thereof, the thickness of said extended portions being so correlated to the heat conductivity of the metal from which they are formed and the area thereof exposed for heat absorption as to maintain said heat-absorbing portions at an effective refrigerating temperature lower than that of the space or material to be cooled.

8'. In refrigerating apparatus, cooled by a solid refrigerant such as water ice, brine ice, or solid carbon dioxide, a solid metallic heat conductor ypresenting surfaces for heat absorption from the refrigerated space or material of greater area than the surface of .the conductor presented in the refrigerant containing space for heat transfer to the refrigerant; the capacity of said conductor to transmit heat along in the direction ofthe refrigerant Afrom the said surfaces presented for heat absorption being sufficient, vby reason of its thickness or cross section. to maintain the said heat absorbing surface areas at a lower temperature than that ofthe refrigerated space or material, said conductor consisting of a continuous thick metal plate extending in the refrigerated space froni the refrigerant containing` space, the said heat-absorbing surfaces being formed by substantially vertical portions of said plate located in the upper part of the refrigerated space, which portions extend vertically from the bottom level of the refrigerant containing space and immediately adjoin the said heat transferring surface located therein, the solid refrigerant being maintained with the said heat-transferring surface, which is located above the bottom of the refrigerated space.

9. Refrigerating apparatus comprising a thermal conductor in the form of a container, an insulating casing for said container, said conductor i having a thickness so correlated to the heat -conductivity ofv the material from whichit is formed, and the area of its surface'exposed for heat absorption as to be capable of maintaining in all parts of the contained space a substantially uni-'- form refrigerating temperature by means of a solid refrigerant in conductive association with containing space, with which portion the solid' refrigerant is to be maintained in direct contact, and other portions of which are extended exteriorly of the refrigerated space or material, the said extended portions being formed by substantially flat sections of thick metal plate metallically joined to one or more edges of, and extending for at least a portion of its length in substantially the same plane as that portion of the conductor wit-h which the solid refrigerant is to be maintained in contact; the said conductor forming a direct, allmetallic, principal path of heat transferbetween the refrigerated space or material and the refrigerant. the thickness of said extended portions being so correlated to the heat conductivity of the metal from which they are formed, and the area 'of their surfaces exposed for heat absorption as to absorb a maior amount of the heat to be transmltted by the said conductor.

11. In refrigerating apparatus for cooling by a solid refrigerant such as water ice. brine ice. or

. gravitationally in continuous conductive relation I tially flat solid refrigerant such as water ice, brine ice, orv

an effective refrigerating temperature lower solid carbon dioxide, a solid metallic heat conductor presenting extended surfaces for heat absorption from the space or material to. be cooled of greater area than the surfaces of the conductor presented in the refrigerantFcontaining space for direct contact and heat transfer with the refrigerant; the capacity of the said conductor to transmit heat along in the direction of the refrigerant from the said surfaces presented for heat absorp- :tion being sufficient, byreason of its thickness with respect to the heat conductivity of the metal from which itis formed and the area of its extended surfaces exposed for heat absorption, to maintain the said heat-absorbing surface areas at an effective refrigerating temperature lower thanA that of the space or material to be cooled, whereby the said heat-absorbing surfaces are adapted to absorb a major amount ofthe heat to be transmitted by said conductor; and the said extended heat-absorbing surfaces being formed by substansections of metal plate metallically joined to one or more edges of and extending for at least a portion of its length in substantially the same plane as that portion of the conductor with which the solid' refrigerant is to be maintained in contact. A

' 12. In refrigerating apparatus for cooling by a solid carbon dioxide, a solid metallic heat conductor presenting extended surfaces for heat absorption from the space or material to be cooled of greater area than the surfaces of the conductor presented in the refrigerant-containing space for direct contact and heat transfer with the refrigerant; the capacity of the said conductor to transmit heat along in the direction of the refrigerant from the said surfaces presented for heat absorption being sufficient, by reason of its thickness with respect to the heat conductivity'of the metal from which it is formed and the area of its extended surfaces exposed for heat absorption, to maintain the said heat-absorbing surface areas at than that of the space or material to be cooled, whereby the said heat-absorbing surfaces are adapted to absorb a major amount of the heat to be `transmitted by said conductor; and the said extended heat-absorbing surfaces being formed by substantially flat sections of metal plate metallically joined to one or more edges of the remaining portions of the conductor, and partiallysurrounding the refrigerated space.

13. In refrigerating apparatus for cooling by a solid refrigerant such as water ice, brine ice, or

solid carbon dioxide, a solid metallic heat conmit heat along in the direction of the refrigerant from the said surfaces presented for heat absorption being sumcient, by reason of its thickness with vrespect to the heat conductivity of the metal from which it is formed and `the area of its extended surfaces exposed for heat absorption, to maintain the said heat-absorbing surface areas at an effective refrigerating temperature lower than that of the space or material to be cooled, whereby the l:said heat-absorbing surfaces are adapted to absorb a major amount of the heat to be transmitted by said conductor; and the said extended heat- .absorbing surfaces being formed by substantially flat sections of metal plate metallically joined to one or more edges of and extending for at least a portion of its length in substantiallyv the same plane as that portion of the conductor with which the solid' refrigerant is to be maintained in contact, that portion of the conductor in contact with the refrigerant being located at or below the bot tom level of the refrigerated space.

14. In refrigerating apparatus for cooling by a solid refrigerant such as water ice, brine ice, or solid carbon dioxide, a solid metallic heat .Iconductor connecting the refrigerant-containing space and the space or material to be refrigerated, said conductor being formed by substantially flat sections of metal plate, a portion of which conductor is to be maintained in continuous conductive contact with the solid refrigerant, and other portions extending exteriorly of the refrigerant'- containing space and adapted to absorb the major amount of heat taken up by the solid refrigerant .from the refrigerated space or material, the said 15. In refrigerating apparatus for cooling by a solid refrigerant such as water ice, brine ice, or solid carbon dioxide, a solid metallic heat conductor connecting the refrigerant-containing space and the space or material to be refrigerated, said conductor being formed by substantially nat sections of metal plate,"a portion of which conductor is to be maintained in continuous conductive contact with the solid refrigerant, and other portions extending exteriorly of the refrigerant-v containing space and adapted to absorb the major amount of heat taken up by the solid refrigerant from the refrigerated space or material, the said latter portions being metallically joined to one or more edges of the said former portion, and par-v tially surrounding the refrigerated space, the thickness of said conductor being so correlated to the heat conductivity of the metal from which it is formed, and the.area of its surface exposed for heat absorption asl to transfer heat from said space at a rate sumcient to maintain an effective refrigerating temperature.

16. In refrigerating apparatus for vcooling by a solid refrigerant such as water ice, brine ice, or solid carbondioxide, a solid metallic heat conductor connecting the refrigerant-containing space-and the space or` material to be refrigerated, said conductor being formed by substantially -at sections of metal plate, a portion of which conductor is to be maintained in continuous conductives contact with the solid refrigerant, and other portions of whichv absorb the major amount of heat taken up by the solid refrigerant from the refrigerated space or material, the said latter portions being metallically joined to one or more edges of, and extending for at least a portion of its length portion of the conductor with which the solid refrigerant is to be maintained in contact, and

the said former portion being located at or below the` bottom level of the refrigerated space, the thickness of said conductor being so correlated to the heat conductivity of the metal from which it is formed, and the area of its surface exposed in substantially the same plane as that 4 for heat absorption as to transfer heat from said space at a rate suilcient to maintain an effective refrigerating temperature.

17. Refrigerating apparatus for use with solid carbon dioxide comprising a thermal conductor having a plurality of tubular extensions each forming a receptacle, an insulating housing entirely surrounding said conductor and said extensions, and means providing for operative association of said conductor with the said refrigerant, said conductor andthe extensions thereof having a thickness so correlated to the heat conductivity of the material from`which they are formed, and the area of surface exposed for heat absorption as to be capable'of maintaining the entire space of each of said containers at a substantially uniform refrigerated temperature. l

18. A refrigerating apparatus for use with a solid refrigerant as the refrigerating medium comprisingY a refrigerant-containing space, a space f to be refrigerated. and a solid metallic heat conductor forming the bottom of the refrigerantcontaining space and adapted to be maintained in heat-conductive relation with refrigerant therein, said conductor having an extended portion forming the bottom of the space to be refrigerated, the thickness of the conductor and the extended portion being so correlated to the heat conductivity of the metal from which they are formed, and the area of the extended portion exposed for heat absorption in the space to be refrigerated being sumcient, that the conductor and the extended portion thereof form a direct, al1-metallic path for transfer to the refrigerant of the major amount of heat absorbed from the space to berefrigerated.

. EDWARD RICE. Jn.

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