US1989609A - Method and apparatus for refrigeration - Google Patents

Description

5 Shee'tsSheet 1 I v I a l I I f v I 4 Ida .Jan. 29, 1935. E. RICE. JR

I METHOD AND APPARATUS FOR REFRIGERATION Original Filed July 14, 1930 5 Sheets-Sheet 2 Jan. 29, 1935. E. RICE. JR

METHOD AND' APPARATUS FOR REFRIGERATION Original Filed July 14, 1930 I I .v u

Jan. 29, 1935. E. RICE, JR

METHOD AND APPARATUS FOR REFRIGERATION Original Filed July 14, 1930 5 Sheets-Sheet 3 llllflfll rllllllll Jan. 29, 1935. E. RICE, JR

METHOD AND APPARATUS FOR REFRIGERATION Original Filed July 14, 1930 5 Sheets-Sheet 4 E d n I E 22%;?!

Jan. 29,1935. E. RICE, JR

METHOD AND APPARATUS FOR REFRIGERATION 5' Sheets-Sheet Original Filed July 14, 1930 254 236 2&7

Patented Jan. 29, 1935 UNITED STATES METHOi) AND APPARATUS FOR REFRIGERATION Edward Rice, In,

New York, N. Y.

riginal application July 14, 1930, Serial No. 467,999. Divided and this application August 25, 1934, Serial No. 741,464

Claims. (01. sis-s) This application is a division of my application for patent filed July 14, 1930, Serial Number 467.999. Y

This invention relates to improvements in methods and means for refrigerating by use of solid refrigerants, such as water ice (solid H), and carbon dioxide ice (solid CO2) r The invention described and claimed herein resides in a novel means for maintaininga solid refrigerant in continuous contact, or in uniform conductive relation, with a substantially vertical portion of a solid metallic heat conductor which absorbs heat from the refrigerated space or material on extended metallic surfaces and transmits this heat to the adjacent surfaces of the solid refrigerant. This is accomplished by providing a supporting base for the refrigerant which is inclined toward a side wall of the refrigerant containing space formed by a portion of the metallic conductor, thereby causing the refrigerant to slide downcontinuously by gravity against the conductor as the refrigerant melts, and to keep the heat absorbing surfaces of the conductor chilled as long as any of the refrigerant remains. Provision is also made for continuously draining away the meltage of the refrigerant so that, when solid refrigerants such as water ice are used, the ice will not float off the inclined base and lose contact with the conductor wall.

An object of the invention is to provide a method of refrigerating by means of' solid refrigerants whereby the effective refrigerating temperatures are to a substantial degree independent of the volume of the refrigerant, and to this latter end, the invention contemplates the provision of a method for materially increasing the refrigerating efliciency of relatively small quantities of a solid refrigerant.

More specifically, 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 refrigeratingtemperatures 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 accelera- A still further object of the invention 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 8 refrigerated space or mass to a conductor of high thermal conductivity and extended surface, and '15 thence conductively to a relatively small surface of the refrigerant through a section of the conductor sufficiently large to transmit the required amount of heat for maintaining a predetermined effective refrigerating temperature.

Still more specifically, as regards the use of solid H20 and similar solid refrigerants of relatively high melting point, an object of the invention is to provide a novel method of refrigeration which will produce effective refrigerating temperatures more closely approximating the melting temperature of the ice than has heretofore been possible, and will maintain such temperatures even after the volume of the ice has been reduced to relatively small amounts.

A further object of the invention is the production of a refrigerating unit of 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 trans portation units.

Still another object of the invention isto provide simple and relatively inexpensive refrigerating units of a character adapted for use in house- 40 hold and other refrigerators employing solid H20 whereby my invention may be readily available for that class of refrigeration.

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 the attached drawings, inwhich:

Figure 1 is a diagrammatic sectional view illustrating an embodiment of my invention as applied to household refrigerators and similar class of refrigeration;

Fig. 2 is a view in perspective of a refrigerating unit adapted for application to household and similar refrigerators and constructed in accordance. with my invention; i Fig. 3 is a diagrammatic sectional view illustrating the method of installing the unit. illustrated in Fig. 2;

' Fig. 4 is a section on the line 4-4, Fig. 1; Fig. ii is a section on the line 5-5, Fig. 3; i .Fig. 6 is a sectional view illustrating a still further embodiment of my invention;

Fig. 'I is a sectional view illustrating the em- ;bodiment shownin Fig. 6 modified for use with solid 00:;

Figs. 8, '9, 10, 11 and 12 are fragmentary sectional views illustrating different types Min all construction suitable for use in the practice of my invention; I

Fig. 13 is a diagrammatic vertical sectional view \illustrating a liquid-cooling apparatus made in v, accordance with my invention; go Fig. 14 is a section on the line 14-14, Fig. 13;

, Figs-15 and 16 are, respectively, a vertical sectional view and a section taken on the line 16-16,

Fig. 15, illustrating a table or cabinet-type of refrigerator made in accordance with my inven as; tion' and in condition for use with solid. carbon .dioxide or other refrigerant of relatively low melting point; I

Fig. 17 is a fragmentary vertical sectional view illustrating the same cabinet.as used with solid so 320 or similar; refrigerant of relatively high meltins p int;

Fig. 18 is a section on the line 18-18, Fig. 17 Fig. 19 is a. diagrammatic vertical sectional view illustrating a desirable type of shipp n container embodying my invention;

Fig. 20 is a more or less diagrammatic vertical sectional view illustrating a type of refrigerator involving the principle of my invention adapted particularly for the cooling of milk and other beverages;

Fig. 21 is a section'on the line 2121, Fig. 20; Fig.22 is a vertical sectional view more orless diagrammatic illustrating a type of store show case refrigerated in accordance with my invention; Fig. 2a is a horizontal sectional view, and

Fig. 24 is a sectional view on the line 24-24, ,Fig. 23, illustrating more or less diagrammatically an.application of my invention to the refrigeration of large truck bodies;

' Fig. 25 is a horizontal sectional view, and

Fig. 26 is a vertical sectional view on the line 26-26, Fig. 25,.illustrating my invention as applied to refrigeration of relatively small truck bodies;

Fig. 2'1 is a diagrammatic vertical sectional view of a well known type of railway express car illustrating the method of'refrigerating in ac-.

cordance with my invention; and

Fig. 28 is a diagrammatic vertical sectional view of a railway car showing another method of refrigeration in accordance with my invention.

Water ice or solid H20 is more widely used than any other form of refrigerant. One of the principal drawbacks in the prior methods of using 85 this refrigerant or, in fact, any solid refrigerant is that although any given mass of the refrigerant,

no matter how small, has a fixed refrigerating value; yet the smaller the mass becomes, the slower its refrigerating action becomes also. This is due to the fact that the heat is usually either entirely or almost entirely brought to the ice convectively either by air or a liquid, and the amount of heat taken up by the refrigerant, other 75 things being equal, depends directly on the amount of the effective surface contact between the refrigerant and the circulating fluid. 'Obviously as the ice'melts, the surface area becomes less and the refrigerating action slower. In the construction of refrigerating apparatus, this feature, heretofore, hasbeen given no consideration,and no effort has been made to compensate for the rapid decrease in e'flici'ency as the re-- frigerant loses volume and surface area. As a result, a great deal of ice is constantly being used 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 field for refrigeration of foodstuffs in motor transportation has avoided theme of water ice.

and other solid refrigerants. Practically the. only 'method attempted to improve the efficiency 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 efllcient use of water ice and other solid refrigerants can 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 substantialcross 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 by this method, the ice can be melted at practically a constant rate, thus providing a constant effective refrigerating temperature practically in-' dependent of the volume 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 ex- ,tended metal surfaces. With a suflficient cross section of the conductor metal, as small as thirty square inches of contact surface with the refrigerant will suffice to melt enough water ice to keep a good household refrigerator below 60 F. even on the top shelf in the warmest weather; and after the doors have been opened as long as three minutes, this refrigerator will return to its original low temperature within twenty minutes or one-half hour. It is essential in the practice of my invention that the solid refrigerant be maintained in conductive relation with a 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 to 45 F. are desired and water ice is to be used by reason of its cheapness and availability, then a relatively large amount of extended conductor or fin surface will be required because of the small temperature differential between the water ice and the temperature required; while the same temperatures can be secured by use of solid carbon dioxide with considerably less surface area by reason of the fact that with solid viously if temperatures arewanted near or below the. melting point of water ice, then some other .solid refrigerant may be "used with a sufficiently 16W melting or subliming. point that the conductor can be put at a temperature aifording the differential required to. maintain the refrigeration wanted. Froaen brine may be used especially when put up in small and easily handled units in liquid-tight metal containers. The heat transferred from the conductor to the solid brine through the metal container. however, is not as constant and controllable as in the direct contact of water ice with theconductor 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 anywhere between 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 refrigerant means in my method of refrigeration. Of course, frozen brine directly-in solid state can be used in the same way as water ice or carbon dioxide ice by permitting the melted brine to drain off;

With reference .to the drawings, in whichI have illustrated various specific applications of my invention to different types and classes of refrigeration, and with particular reference to Figs. 1 and 4. the reference numeral 1 may indicate the outer shell or case of a household refrigerator of well known type, this refrigerator including a central vertical bafiiewall 2 and a compartment 3 in one of the upper comers for reception of the refrigerant. In accordance with the prior practice, refrigeration is obtained in this type of refrigerator by the convective action of air currents circulated as indicated by the arrows downwardly over and around the ice in the compartment 3, downwardly'through an aperture 4 provided in the base of this compartment, under the baffle 2, and upwardly in the main refrigerating chamber 5. In accordance with my invention, I provide within the chamber 3 shelves 6, 6. for reception of the refrigerant, which shelves incline inwardly towards a conductor 7 provided with a plurality of pro- Jecting fins 8, as most clearly shown in Fig. 4.

Inclination of the shelves 6 insures retention of the face of the ice masses 9 supported on these shelves in close contact with the conductor 7, which latter is located as shownin relation to the baffle wall 2 so as to provide between the vertically arranged fins, the conductor 7, and the baffle vertical passages through which the convective currents circulate downwardly over the extended surface of the conductor. As the ice melts, the latter feeds by gravity up against the conductor, thereby maintaining continuous contact between one face of the ice massesand the conductor. The ice meltage passes out through the usual drain 11,and the air after circulating over the conductor and its fins comes in contact with this melted ice water, which removes the undesirable odors from the air, and then passes from the refrigerator. With apparatus of this type, it is possible to maintain relatively low temperatures within the casing even when the ice has been reduced to a very small volume.

the conductor and the refrigerated space. Ob-

refrigerating unit made in accordance with my In Fig. 2 I have-illustrated in perspective a invention and of a'type adapted. for insertion in household refrigerators of the usual type. This unit comprises a rectangular casing 12 open at top and bottom and having in the interior a plurality of vertical fins 13; At the lower end of the forward wall is a depending apron 14 which at its bottom edge turns upwardly to form a channel adapted to receive the drip of the melting ice, and from this channel extends downwardly a drain pipe 15. The unit also com,-

prises an inclined shelf 16 which provides for maintaining continuous contact between the refrigerant and the inner vertical wall- 17 of the unit. Preferably this wall 17 of the unit and the fins 13 are made of copper, aluminum or gthteg metal having a relatively-high conductivity ac r. I.

As shown in Fig. 3, this unit'mayl be secured in an upper corner of the refrigerator case 18,

it being noted that the forward wall 19 of; the

unit terminates at the top at a' point below the upper end-of the fins 13, whereas the. rear wall 17 extends to the top of the fins which, in the present instance, abut the upper or top wall of the casing. In this manner, a circulation of the convective air currents is set up downwardly throughtheunit between the fins 13 and over the face of the rear conductor wall 17. The meltage passes through apertures at the inner or lower end of the. shelf 16 and falls downwardly into the channel apron 14- whereby the air currents after passing over the surfaces of the conductor pass through the dripping water, which latter acts to remove the refrigerator odors from the air. In order to prevent excessive con-1 densation moisture and possible dripping of this 7 moisture from the shelf 16 on the stored food, the latter preferably is provided with a layer of suitable insulating material 21.

It will be noted that each of the devices described above meets the essential requirements of my invention. In each instance, a conductor is provided for conducting heat from the space to be refrigerated to the refrigerant. This conductor is so formed, with fins in the present instance, as to present to the space to be refrigerated a relatively extended area, and its cross sectional dimensions are entirely adei uate to transmit heat in required amount picked up on the said extended surfaces to the surface or surfaces of the ice with which the conductor is in direct contact. Since in the use of water ice this direct conductive contact between the conductor and the ice is essential, provision is made in the form of the inclined ice-supporting shelves to maintain the refrigerant in constant contact with the conductor. With this arrangement, the heat maybe carriedto the refrigerant at a rate insuring maintenance of a predetermined adequate effective refrigerating temperature in the refrigerated space even when the ice has been reduced to an extremely small volume. With this vertical and horizontal walls. At the junction of these two walls an outlet pipe 37 is provided for by the horizontal fins, and a higher temperature in a comparatively large compartment in which the convection currents pass over the vertical fins. The lower wall of the unit in assembly is inclined towards the vertical wall so that the ice tends to maintain a positiongin the angle with adjoining faces in contact with the vertical and bottom walls respectively.

Fig. 7 shows a type of conductor of primary value in connection withcarbon dioxide ice. This unit comprises an angular casting 38 of aluminum with copper fins 39. The ice-supporting wall is slightly inclined towards the juncture with the upright wall, and in the angle outlets 41 are provided for elimination of the gases of sublimation. The principal heat transfer in this instance takes place through the thin copper fins, down the upright side of the casting to the bottom or icesupporting wall. Interposedbetween the solid carbon dioxide and this lower wall is a suitablyselected conductor resistance 42, and the ice is also surrounded by suitable insulation 43.

In Figs. 8 to-12, inclusive, I have illustrated various types of fin conductors which have been found suitable in the practice of my invention.

The form of conductor illustrated in Fig. 8 is one that can be conveniently used for household refrigeration purposes, this being made up from a number of bent copper sheets 45 soldered together at the points designated 46 so as to present a substantially flat conductor plate surface for contact with the solid refrigerant and a considerably extended fin surface for contact with the convection currents.

Fig. 9 shows a similar construction in which the outer ends 47 of the projecting fin portions are turned inwardly toward each other so as to afford the same amount of contact surface in a more restricted space.

Fig. 10 shows a more eflicient type of conductor in which thin copper fins 48 are soldered or welded to ,a heavy copper conductor plate 49.

Fig. 11 shows a still more efiicient but more expensive form of conductor consisting of a solid aluminum plate 51 with thin copper fins 52 secured to the aluminum plate by casting the latter on the fins.

- Fig. 12 shows an all-aluminum fin conductor formed of a single casting.

Figs. 13 and 14 illustrate a desirable form of water cooler adapted for use with water ice. The refrigerator comprises a copper tank 71, one side of which forms an abutment for the refrigerant which is maintained in contact therewith by gravity through the medium of an inclined support '72. From this refriger'ant-abutted wall fins 73 project into the interior of the tank, which as illustrated has an inlet pipe 74 preferably emptying directly above the said fins. The arrows indicate the direction of the convection currents set up within the tank which carries the contained liquid over the surfaces of the fin conductor wall. This is a very efiicient form of liquid cooler in which the temperature of the liquid is reduced very rapidly, and by extending the insulating casing '75 rearwardly, the latter can be given any capacity required for the solid refrigerant to maintain the refrigerating action over very extended periods of time. As the ice melts, it will be understood that it feeds continuously by gravity towards'and against the conductor plate of the tank 71.

In Figs. and 16, I have illustrated a large table or cabinet type of refrigerator adapted for use either with CO: ice or water ice and in which provision is made for obtaining in the three separate compartments three' different temperatures, when COaice is used, or of two temperatures when water ice is employed. This refrigerator consists of an outer insulated casing 111 having in the top a chamber for a refrigerant, the opposite sides and the bottom of which are constituted by a channel-shaped conductor 112. The side walls of this conductor are provided with outwardly projecting fins 113,.and the bottom wall is slightly elevated towards the center to.

to this refrigerating chamber is had through a removable cover 114. Three refrigerating chambers are provided numbered 115, 116. and 117, respectively, the chamber 116 being located directly below the refrigerant chamber. Baiiles 118 in the chambers 115 and 117 extend vertically and preferably in contact with the outer edges of the fins 113 whereby a convective circulation is set up in which the air moves downwardly between the fins and against the side walls of the conductor. The chamber 116 is separated from the other chambers by insulating walls 119, and in one or both of the chambers 115 a valve 120, which may be operated manually or automatically from a suitable thermostatic actuator, is provided for controlling the movement of the convection currents downwardly past the walls and fins of the conductor. Where car bon dioxide ice is used, the refrigerant is surrounded in the refrigerating chamber on four sides and the top by suitable insulation 121, while the ice is separated from the bottom of the conductor by means of suitable conductor resist- .ance 122. The temperature in the chamber 116 is controlled by the thickness and character of the conductor resistance, whereas the temperatures in the compartments 115 and 117 are controlled not only by the conductor resistance, but also by the thickness and character of the insulation 121, and may be still further controll by manipulation of the valve 120.

Figs. 17 and 18 illustrate this same apparatus as used with water ice, it being noted that in this case the insulation 121 and. the conductor resistance 122 are removed, the water ice. being' maintained in contact with the side walls of the conductor by reason of the inclination of the bottom wall after a manner previously set forth.

Fig. 19 illustrates a portable shipping container for refrigerating purposes for use with either water ice or solid carbon dioxide, and in which provision is made for maintaining different temperatures in the refrigerating chambers. The construction is essentially the same as that illustrated in Figs. 15 and 16, one of the refrigerating chambers being provided with a valve 12.5 in the major convection passage whereby movement of the air past the conductor may be suitably controlled.

In Figs. 20 and 21, I have illustrated a desirable form of cabinet refrigerated in accordance with my invention and adapted for the rapid cooling of milk or other beverages. The insulated cabinet 175 encloses a chamber 176 adapted for reception of the refrigerant. One wall of this chamber 176 is constituted bye conductor 177, this conductor having on its outer face a plurality of vertically arranged sets of inclined fins 178. Shelves 179 are provided in the interior of the chamber 176 for support of the refrigerant, and these shelves are inclined downwardly to-. wards the conductor wall 177 so that the ice as it melts will'feed by gravity downwardly towards the conductor and remain continuously in contact therewith over a substantial surface area of the refrigerant From the chamber 176 the ice meltage escapes to the atmosphere through a port 181. The fins 178 project into a chamber 182, in the open topof which is established a receptacle 183 having in the bottom a discharge opening or openings 184 located immediately over the tops of the upper bank of fins 178. From the bottom of the chamber a duct 185 extends outwardly to a spigot 186, through which the contents of the chamber 182 may be withdrawn. Milk or other beverage poured into the container 183 trickles through the 'openings184 ontothe fins 178 and flows downwardly over the lower banks of fins in a tortuous path aflorded by the relative angular arrangement of the said banks. Refrigeration of the beverageis immediate, and it may be withdrawn immediately from the tube 186 in a cooled condition. The refrigeration also may take place by filling the chamber 182,and permitting the liquid to pass over. the surface of the conductor and of the fins 178 by convection. It will be noted that the casing 175 also encloses a chamber 187 the bottom of which may constitute a storage space for containers 188 for the particular beverage in connection with which the apparatus is used. I

In Fig. 22, I have illustrated a well known form of store show case refrigerated in accordance with my invention. In the rear of'the case is a chamber 191 for the refrigerant, this refrigerant resting upon an inclined base 192 which effects a continuous contact between the refrigerant and a conductor plate 193. This plate has fins 194 projecting into the storage space of the show case, and a battle 195 and false bottom 196 in the case afiord a passage for directing the air currents circulated by convection through the case, as indicated by the arrows.

Figs. 23 and 24 illustrate a method of refrigerating large truck bodies or the like in accordance with my invention. The body isindicated by the reference numeral 212, doors 213 being provided affording access to the interior. At the top and at one side of the body a chamber 214 is provided for the refrigerant, this chamber having in the present instance side walls 215 formed of copper, aluminum or other suitable material having a high conductivity factor. These conductor plates 215 are provided with fins 216 which project into the interior chamber of the truck, and the truck interior is also provided with suitable bafile plates or false walls 217 which form channels for conduction currents, as indicated by the arrows, which currents pass downwardly through the fins 216 and over the surfaces of the conductor plates 215 whereby a thorough and rapid refrigeration of the interior of the truck body is effected. It will be noted that the shelves 218 which support the refrigerant are slanted downwardly toward the conductor plates 215 whereby the refrigerant is maintained continuously in contact or in conductive relation with the plates in the manner previously set forth.

Another feature of the construction shown in 75 24 is the radiation -shield or false top 219 which pi'ferably extends an the entire .001

of the body. in spaced relation to the latter, this shield preferably being made of hard bright metaltending to deflect the heat rays of the same and preventing direct contact ofthe rays with the top wall of the refrigerated chamber.

'In Figs. 25 and 26, a refrigerating system is illustrated suitable for small truck bodies and the like and adapted for refrigeration with practically any type'of solid refrigerant. Thebodyf221 in this instance has a chamber 222 at oneend and in the upper portion for reception of the refrigerant, the bottom and front-wall of this spacebelng constituted by a suitable angular "conductor plate 223, and the said front 'wall being.

provided with fins 224 which project into'the interior or refrigerated area of the truck.- The space directly under} the bottom of the conductor plate 223 is enclosed by'a partition 225; and constitutes a cold compartment'whose temperature may bemaintainedat a relatively low point. A false wall or baffle 226 is provided in theinterior of the body whichforms a channel for the circulation of "the convection currents, as indicated by the arrows, the circulating air-passing downwardly over the upright. face of *the conductor 223 and between the fins 224. I also may provide in this instance a valve 227 in-the air passage ployed, this refrigerant willbesurrounded by an insulating sleeve228 and separated from the bottom of the conductor member by a, suitable conductor resistance element 229. The temperatures may be controlled by regulatingthe thickness and character of the conductor resistance and of the insulating sleeve 228. Where water ice is employed, the sleeve228 and conductor resistance 229 may be eliminated. It will be noted that in this case also I employ on the top of the truck body a suitable radiation shield 231.

Fig. 27 shows a well known type of railway express car well adapted to refrigeration in accordance with my invention. The car body 232 has a dome-like roof 233, and in the interior-and depending from the roof 233 is a refrigerating unit, one or more, each consisting of a receptacle for the refrigerant, the sides 234 of which and the bottom 235 are made of a material such as copper or aluminum having a relatively high conductivity factor; 'I'heside walls 234 of the conductor are provided with fins 236 which project outwardly into the refrigerated interior of the car, and outwardly of these fins baflle partitions convection currents downwardly over the surface of the conductor walls 234 and the fins 236. False walls or baflle partitions 238 are also provided for further controlling the circulation of the air, which is substantially as indicated by the arrows. The bottom wall 235 of the refrigerating unit may be protected on the under side by suitable insulation 239 to prevent 'condensa- .237 are provided which guide the circulating Erigerating units are provided in each of the upper corners of the car, the units being designated by the reference numeral 243 and being constructed in accordance with the principles set forth above. The usual partitions are provided in this instance for controlling the convection currents and for guiding the currents over the conductor surfaces of the refrigerating units.

I claim:

1. In apparatus for, refrigerating with solid refrigerants, the combination with a refrigerantcontaining chamber, of a solid thermal conductor of a highly conductive metal extending from said chamber to the space to be refrigerated and presenting to the latter a surface area materially greater than the surface area in contact with the refrigerant body, and means in said chamber for supporting the refrigerant in continuous conductive relation with an upright portion of said conductor, which portion forms a side of said refrigerant-containing chamber.

2. In apparatus for refrigerating with solid refrigerants, the combination with a solid thermal conductor of a highly conductive metal having an extended surface area exposed in the space to be refrigerated materially exceeding the surface area in contact with the refrigerant body, and means for maintaining the refrigerant in continuous conductive relation with an upright portion of said conductor, which portion forms a side of the refrigerant-containing space.

3. In a refrigerator, the combination with a solid thermal conductor of ahighly conductive metal having surface areas exposed to the refrigerated chamber materially in excess of the surface area in contact with the refrigerant body, and a support for a solid refrigerant adapted gravitationally to maintain the refrigerant in continuous conductive relationwith an upright portion of said conductor, which portion forms a side of the refrigerant-containing space.

4. A refrigerating unit comprising a solid thermal conductor of a highly conductive metal having an extended surface area in the space to be refrigerated materially exceeding the surface area in contact with the refrigerant body, and a refrigerant support inclined toward the said conductor whereby a solid refrigerant on.,said support will gravitate towards the said conductor.

5. A refrigerating unit for use with solid refrigerants comprising a conductor having an extendedsurface in the space to be refrigerated and presenting to the latter a surface area materially greater than the surface area in contact with the refrigerant body, a support for the refrigerant slanting toward the conductor whereby a solid refrigerant is held by gravity in con- 6. A refrigerating unit comprising a thermal conductor having an extended surface area, par tition means embracing said surface and forming an open-ended duct through-which a fluid may circulate in contact with said surface, and a refrigerant support inclined towards the said conductor whereby-a solid refrigerant on said support will gravitate towards the said conductor.

'7. A refrigerating unit comprising a thermal conductor having an extended surface area, partition means embracing said surface and forming an open-ended duct through which a fluid may circulate in contact with said surface, and a refrigerant support inclined towards'the said conductor whereby a solid refrigerant on said support will gravitate towards the said conductor, the said support being formed by a portion of the said conductor.

8. A refrigerating unit comprising a thermal conductor having an extended surface area, partition means embracing said surface and forming an open-ended duct through which a fluid may circulate in contact with said surface, and a refrigerant support inclined towards the said conductor whereby a solid refrigerant on said support will gravitate towards the said conductor, together with means for continuously draining off the meltage of the refrigerant from the lower part of the refrigerant-containing space.

9. In refrigerating apparatus in which a vertical heat-absorbing metal wall is cooled by a solid refrigerant, the method of maintaining the solid refrigerant in continuous conductive relation with said wall, which consists in supporting the solid refrigerant on an inclined base, whereby the refrigerant tends to gravitate against said wall, and continuously draining off the products of dissolution of the solid refrigerant. 10. In refrigerating apparatus, cooled by a solid refrigerant such as water ice, brine ice, or solid carbon dioxide, in which a substantially vertical metallic side wall of the refrigerant-containing space absorbs heat derived from the refrigerated space or material, the combination with means for maintaining the solid refrigerant in continuous contact with said wall, said means including a. support for the refrigerant inclined toward the said wall.

- EDWARD RICE, JR.

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