US2045250A - Refrigerating apparatus - Google Patents

Description

m 1936- c. E. QUINN 2,045,250

' I REFRIGERATING APPARATUS Original Filed July 10, 1934 2 SheetsQ-Sheet l iNvENTqR g f. 041/ 17/7 June 23, 1936.

0. E.- QUINN REFRIGERATING APPARATUS Original Filed July 10, 1934 2 Sheets-Sheet 2 INVENTOR Patented June 23, 1936- 2,045,250 v REFBIGEBATING APPARATUS Clara E. Quinn, Mount Vernon, 11]., assignor to Driice Appliances Incorporated, Mount Vernon, 111., a corporation of Delaware Application July 10, 1934, Serial No. 734,474 Renewed November 19, 1935 8 Claims.

This invention relates in general to improvements in refrigerating apparatus of the type employing a primary refrigerant and a secondary circulating refrigerant. The basic object of this invention is to provide an improved form of refrigerator construction in which dry ice is utilized through the agency of a closed circulatory system for a liquid secondary refrigerant, functioning to abstract heat from the spaces to be refrigerated.

The broad general object of the invention involves the arrangement of the apparatus so as to more efficiently-utilize the refrigerating capabilities of solid refrigerants and more particularly solid carbon dioxide.

Another object of the invention is to accomplish the utilization of a constant temperature solid primary refrigerant for use in maintaining different spaces at different temperatures.

These and many other objects, as will be apparent from the detailed description, are secured 1 by means of this invention.

This invention resides substantially in the combination, construction, arrangement and relative location of parts, all aswill be set forth in full detail below, I I y In the drawings,

Figure 1 is a vertical, longitudinal, cross-sectional view through a refrigerator in accordance with this invention, along the line l--l of Figure 2;

Figure 2 is a cross-sectional view on the line 22 of Figure 1;

Figure 3 is an elevational view with a portion broken away ofone of the hollow fins forming part of the circulatory system;

Figure 4 is a cross-sectional view taken on the line 4-4 of Figure 3;

Figure 5 is an outside elevational view of the container for the solid refrigerant and for the main body of the secondary refrigerant;

Figure 6 is a front elevational view thereof;

Figure '7 is a view partly in cross section of a modified form of refrigerator in accordance with this invention with some parts broken away; and

Figure 8 is a cross sectional view taken on the line 88 of Figure '7.

The form of the device in accordance with this invention, as depicted in the drawings for purposes of illustration, is shown comprising a casing l of any suitable material, .shape and size, depending upon practical requirements. This casing is provided with a layer of heat insulating material 2 of cork or similar materials of the proper thickness to exclude outside heat. Mounted centrally within theinsulated chamber thus formed is a metallic container 3. This container is double-walled and is so shaped as to provide an internal pocket or cavity which receives the-solid refrigerant, such as carbon dioxide, and as indicated at 4. Outside views of this double-walled metallic container 3 are shown in Figures 5 and 6. As is clear from the figures, one side or leg of the container extends above the terminal plane of the other sides. As indicated in Figure 6, at distributed points along a vertical line a plurality of tapped openings 30 are provided, into which the delivery pipe from the container 3 to the cooling fins may be secured.

This feature of the distributed tapped outlets is an important one since it is by means of this arrangement that with a single body of secondary refrigerant spaces may be held at different temperatures. In accordance with thermo-dynamic principles the warmer liquid will be at the top of the container and will be relatively colder towards the bottom. This characteristic is increased in accordance with this invention intwo ways. In the first instance, it is accomplished by extending the leg 3 upwardly for a greater dis- I tance and providing the take-off connections at different points, thus providing a supply of the secondary refrigerant at different temperatures.

For example, it has been found by actual practice with a structure ,of certain dimensions that for each inch of spacing between centers of the takeoff connections a difference of five degrees in the temperature of thesecondary refrigerant is'secured. The extension comprising the longer leg provides lower temperatures of the refrigerant than would be possible without it. In the second place, the temperatures in any one of the legs and, as illustrated, in the longer leg, is further reduced, if desired, by means of an insulating plate or wall 40 interposed between the solid refrigerant and the inner face of the wall of the longer leg. If lower temperatures are desired the take-oifs may be at other points, as illustrated, and will be described later. Surrounding the top of the con tainer 3 and extending between it and the top of the cabinet and in alignment with the opening I4 is the wood 'or other insulating backs or casing I 5 which isolates the interior of the main cabinet from the solid refrigerant chamber.

The top of the main cabinet is also provided with a plurality of other openings I 4 underwhich are mounted the tanks or containers 6 in which the perishable products are charged, such as ice cream, food. and the like. In the form illustrated, there are twelve of these containers, six

on each side of the container 3, and arranged transversely in pairs. Interposed between the containers at the left is the long, thin, fiat, hollow, fin-like member 1, which may be supported in any suitable manner and preferably in spaced relation with respect to the cabinet walls. The inlet for this hollow fin is provided by a pipe 9 which connects it to the container 3 at such a point as to be in communication with the secondary refrigerant at a desired temperature. This connection illustrates the point that where lower temperatures are desired the take-off may be at some point other than the tapped apertures 30. The return pipe connection from the fin I is shown at 8 and extends into the top of the longer leg so as to discharge the warm refrigerant into the warmest part of the liquid body.

On the other side of the center and interposed between the pairs of containers 6 is a hollow fin in similar to fin I but of less vertical extent. This fin is supplied with secondary refrigerant of a higher temperature through the connection 12. The return fiow is through the pipe H. The smaller fin illustrates an additional way in which the containers at the right are maintained at higher temperatures than the containers at the left, using but a single body of secondary refrigerant. This fin i0 is also mounted so as to be at the top or warmer portion or part of the cabinet. The container 3 is connected to an expansion tank I 3 which provides excess volume to be taken up as necessary when the volume of the secondary refrigerant increases as it becomes warmer. This feature is necessary in the event that if the entire apparatus is not used there will be a place for the liquid to expand into without danger of the creation of undesired pressures.

Another feature of this invention resides in the plate 50 which is of thin metal, such as galvanized iron, for example, copper, or the like, which when interposed between-the block of solid carbon dioxide and the floor of the cavity in the container 3 will raise the general temperature level of the secondary refrigerant a few degrees. Under some conditions of operation this may be desirable.

Those skilled in the art will appreciate the manner in which the apparatus operates from the above description. It seems desirable to point out, however, that the secondary refrigerant will circulate from the container 3 through the pipes 9 and i2 to the hollow fins I and I0, respectively, and return therefrom to the container 3 through the pipes 8 and II, respectively, by reason of the natural thermo-syphonic action which occurs. By means of this device, solid carbon dioxide,. which is of notoriously low natural temperature, may be practically and eifectivelyemployed to keep food and otherperishable products at higher and more practical temperatures, namely, on the order of 32 F. It will likewise be apparent to those skilled in the art that the various ways in which different temperatures may be maintained employ a single source of primary refrigerant and a single body of secondary refrigerant.

The refrigerator cabinet is shown at 60 and, as in the case of a previously described structure, may be in the form of a refrigerating container, such as a household refrigerator, a store refrigerating cabinet, a truck body, a railroad car, or the like. This cabinet is, of course, to be lined with the necessary layers of insulating material, in accordance with well known practice, toprevent the entrance of heat thereinto. Suitably located with in the cabinet and in alignment with the necessary charging opening which has a removable "through pipe 61 and valve 68 to the top of the cover i5 is a heat insulating casing iii which encloses the metal container 62 which provides the main storage reservoir for the secondary refrigerant. The container 62 is shaped to form an open-topped, double-walled casing into which the 5 blocks of solid refrigerant 63, such as solid carbon dioxide, may be charged. These blocks are preferably covered with a heat insulating cushion 64 of fibrous or other material. Extending from the top of the double-walled container 62 to the undersurface of the top of the cabinet 60 is a heat insulating tubular member 80 which has been shown in this case as made of wood. Connected to the top of the reservoir 62 is a small expansion tank 65 into which the secondary refrigerant 15 which normally fills the container 62 at operating temperatures may expand at higher temperatures. At 66 is a refrigerating fin which extends into the space to be refrigerated. This fin, as before, is of metal in the form of a very thin fin-like member, preferably of rectangular cross-section as illustrated in Figure 8. The depth of the space formed by the fin is small and of the order of onequarter to three-quarters of an inch so as to provide a very thin body of secondary refrigerant in contact with the walls of the fin, which are of relatively large area.

This description applies to the features of the arrangement of Figure 1 and represents an important feature of the invention in that the refrigerating capacity of the secondary refrigerant is quickly made available by the distribution of the refrigerant over the large middle areas of the fin. To aid in the abstraction of heat from the space by the fin, it is in turn provided with a plurality of metal collars 16 which extend transversely of the plane of the fin and are in heat conductive contact therewith. This arrangement increases the effective area of heat absorption so that the space is quickly refrigerated and maintained in that condition. Secondary refrigerant is supplied from the bottom of the reservoir 62 to the bottom of the fin 66 by the pipe 69 and its branches. The warmed refrigerant flows back 45 reservoir 62. To show another way in which dif- -ferent temperatures may be maintained in the same cabinet with the same refrigerant, another fin 10 without the collars is shown. This fin is supplied with refrigerant through the connections 13, and the return flow is effected through the pipe H in the valve 12. Both fins are connected to theexpansion tank by the pipes 14 so that the refrigerant in the fins, if it is unduly warm, may likewise return under the expansion force to the tank 65. As will be apparent to those skilled in the art, the collars 16 may be soldered, brazed or welded to the fins, if desired, to increase efficiency of heat transfer therebetween.

It is, of course, apparent to those skilled in the artthat any one of a number of known secondary refrigerants may be employed, depending upon the temperature conditions to be secured and maintained in the apparatus.

From the above description, it will be apparent that this invention resides in certain principles of construction and operation which may be carried out in other ways by those skilled in this art. I do not, therefore, desire tobe strictly limited to the disclosure which has been given 70 for the purpose of illustrating the invention in one form, but rather to the scope of the claims.

What I seek to secure by United States Letters Patent is: I

v 1. In a refrigerating apparatus, the combina- 76 metal fins within said container, supply and return pipe connections between the reservoir and the fins, a solid refrigerant within the reservoir receptacle, and means for insulating one.

wall of the reservoir from the solid refrigerant, one of said fins having its supply connection in communication with the side of the reservoir adjacent the heat insulating means and the other fin having its supply connecting with another side of the reservoir, whereby the temperature of the secondary refrigerant going to the fins is at different temperatures.

2. In a refrigerating apparatus as described, the combination comprising a heat insulated container, a reservoir within the container adapted to provide a receptacle for a solid refrigerant and to contain a secondary refrigerant, at least two thin, hollow, metal fins within separated spaces within the container, and supply and return pipe connections between the reservoir and the fins, one of said fins being supported centrallyof its associated space from the bottom upwardly and the other near the top of its associated space, whereby the spaces are maintained at different temperatures.

3. In a refrigerating apparatus as described, the combination comprising a heat insulated container, a reservoir within the container adapted to provide a receptacle for a solid refrigerant and to contain a secondary refrigerant, at least two thin, hollow, metal fins within separated spaces within the container, and supply and re-- turn pipe connections between the reservoir and the fins, said fins being of different areas and exposed to areas at different levels in the separate spaces whereby the corresponding spaces are maintained at different temperatures, and at least one of said fins being provided with a plurality of metal collars projecting from the surfaces thereof and in heat conducting contact therewith.

4. A refrigerating apparatus, comprising a heat insulated container, a metal reservoir within the container shaped to form a receptacle for a solid refrigerant and to provide a container for a secondary refrigerant, the solid and secondary refrigerants being in heat exchange relation by conduction through'the wall of the reservoir, a pair of fins mounted in isolated spaces within the container, and pipe connections between the reservoir and the fins for supplying secondary refrigerant to and returning it from the fins, the supply connection for one of the fins being taken off at a different level with respect to the supply connection of the other fin.

5. In a refrigerating apparatus, a heat insulated container providing a plurality of isolated spaces to be refrigerated, a double-walled reservoir within said container shaped to provide a receptacle for a solid refrigerant and adapted to contain a secondary liquid refrigerant, one side of said reservoir being of greater area than the other, hollow circulating fins in said spaces, a connection from the side of greater area of the reservoir to one of said fins, a connection from another side of the reservoir to another fin and return connections from said fins to said reservoir whereby the secondary refrigerant flowing to the fins is at difl'erent temperatures.

' 6. In a refrigerating apparatus, a heat insulated container providing a plurality of isolated spaces to be refrigerated, a double-walled reservoir within said container shaped to provide a receptacle for a solid refrigerant and adapted to contain a secondary liquid refrigerant, one side of said reservoir being of greater area than the other, hollow circulating fins in said spaces, a connection from the side of greater area of the reservoir to one of said fins, a connection from another side of the reservoir to another fin, return connections from said fins to said reservoir whereby the secondary refrigerant fiowing to the fins is at different temperatures, and means for impeding the direct fiow of heat from the side of larger area of the reservoir to the solid refrigerant.

'7. Refrigerating apparatus comprising a heat insulated cabinet, a metallic tank for liquid secondary refrigerant and having a wall for supporting a solid refrigerant in heat exchange relation with the secondary refrigerant, hollow metallic containers disposed within the cabinet to refrigerate separated spaces therein, and supply and return connections between the tank and containers forming a closed circulatory system therewith for the secondary refrigerant, the supply connections being made to the tank at points of different distance from the supporting wall of said tank.

8. In a refrigerating apparatus, a heat insulated cabinet providing a storage space to be chilled, a double walled metallic container in said cabinet formed to support a solid refrigerant on one wall thereof and to contain a secondary liquid refrigerant within the double walls, the double walls of the cmtainer at one side extending to a higher elevation than the other walls thereof and a heat absorbing conduit extending into the storage space and connected at its supply end near the bottom of said container and at its return end to the higher walls of the container at a point above the top of the other walls thereof.

CLARA E. QUINN.

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