US1927168A - Refrigerating apparatus - Google Patents

Description

Spt. 19, 1933. J. c. GoosMANN REFRIGERATING APPARATUS 3 Sheets-Sheet l Filed March 17, 1932 INVENTOR 7245+445 C- Gooaman Sept. 19, 1933. J, GQOSMANN 1,927,168

l REFRIGERATING APPARATUS Filed March 17 1932 3 Sheets-Sheet 2 u/a fed Cor/f INVENTOR BY Jhsfas c. Gmmaw A RNEYG.

Sept 19, 1933 J. c. GoosMANN REFRIGERATING' APPARATUS Filed March 17. 1932 3 Sheets-Sheety 5 INVENTQR J'usus C- Goosmarm BY A RNEYS.

Patented Sept. 19, 1933 PATENT OFFICE REFRIGERATING APPARATUS Justus C. Goosmann, Mount Vernon, N. Y.

Application March 17, 1932.

(Cl. (i2-91.5)

4 Claims.

This invention relates in general to refrigerating apparatus, and more particularly to refrigerating apparatus employing a solid refrigerant, such as solid carbon dioxide, and an automatically operating arrangement for maintaining the space to be refrigerated between predetermined temperature limits.

One of the objects of this invention is to provide an improved and simplified form of refrigerating apparatus employing preferably for the refrigerant solid carbon dioxide.

A further object of this invention is to lpro-- vide a refrigerator cabinet of double wall construction to provide a storage space and an inner refrigerant.

A still further object of this invention is to provide tubular connections between the refrigerant container and the double walls of the cabinets through which the gas formed by the sublimation of the solid carbon dioxide may be conducted so as to occupy'the spaces between the double walls.

A still further object is to provide automatically operating discharge valves for permitting the escape of the gas from the outer cabinet at substantially atmospheric pressure.

A still further object of the invention is to construct the inner refrigerant cabinet so as to provide a metallic wall in contact with the refrigerant and insulated from the space to be refrigerated, an outer metallic wall insulated from the refrigerant and exposed to the space to be refrigerated, and a temperature control device for connecting and disconnecting said metallic walls to automatically maintain a predetermined z temperature in the space to be refrigerated.

These and many other objects, as will appear from the following disclosure, are secured by means of this invention.

This invention resides substantially in the combination, construction, arrangement, and relative location of parts as will be described in detail hereinafter and set forth in the appended claims.

Referring to the drawings- Figure 1 is` a cross-sectional view taken on the line 1--1 of Fig. 2;

Fig. 2 is a. cross-sectional View taken'on the line 2--2 of Fig. 1;

Fig. 3 is a cross-sectional view taken on the line 3-3 of Fig. 1;

Fig. 4 is a plan view of the gas escape valve;

Fig. 5 is a vertical cross-sectional view through this valve;

Fig. 6 is a composite cross-sectional view through various parts of the device showing the details of construction in enlarged form;

Fig. 7 is a plan view of the thermostatic heat conductor;

double wall cabinet for containing the solid Serial No. 599,406

Fig. 8 is a vertical cross-sectional view of this device;

Fig. 9 is a vertical cross-sectional view through a portion of'the side wall of the inner cabinet, and particularly at the point where the thermostatic conductor is mounted; and

Fig. 10 is an elevational view'of the thermostatic conductor with some parts broken away.

The use of solid carbon dioxide as a refrigerant for maintaining the desired temperatures within spaces to be refrigerated, as well as Within storage cabinets for perishable food products, is highly desirable both from a, viewpoint of economy, cleanliness, and heat efficiency. However, it has been generally found rather difficult to employ solid carbon dioxide for this purpose witha maximum of efciency. As is well known, temperature of solid carbon dioxide is of the order of 110 F., an extremely low temperature and one far below the normal requirements for maintaining perishable products against spoilation. It is an important object of this invention, therefore, to provide a refrigerating and storage cabinet employing this intensive cold refrigerant in an economical and efficient manner and at the same time maintaining the temperature of the space to be refrigerated within the necessary limits for perishable products. It is also another object of this invention to accomplish this automatically.

At this point it should be noted that the type of refrigerating cabinet is not of the essence oi this invention and hence the cabinet disclosed and described in detail below has been given for purposes of illustration only. For example, the principles of this invention may be equally well applied to refrigerator cars, refrigerated automobile bodies, refrigerated display counters, and many other similar devices, as well as to the ordinary storage ice box. It will, likewise, be apparent from the following description that the invention is not necessarily limited to the use of solid carbon dioxide as a refrigerant, although finding its greatest value when used in connection therewith.

Referring to the drawings, the'outer cabinet which provides the storage space is shown in the form of a double wall structure. An outer framework suitably formed of the members 1 is covered with a sheet metal cover 2 and reinforced at the corners by means of the angle pieces 3. The inner wall of this cabinet is shown comprising frame members 5 lined with a metal wall` 7. This inner wall is supported upon and spaced from the outer wall at the bottom by means of the bottom members 6 and the supporting and spacing members 4. The bottom space between these two walls is preferably filled with granulated cork, as indicated at 15. The space between these walls is closed at the top by the members 8 which support frame members 9 formed to provide cover receiving seats, of which any desired' number may be employed.

As shown for example in Fig. 3 there are two hingedly mounted closure doors 2'7 and 29 through which access to the interior of the cabinet may be secured. Extending vertically between the double walls around all sides of the cabinet, as is clear from Figs. 1 and 3, are the Walls 10 of some suitable heat insulating material, such as building pasteboard. Building pasteboard is well known in the arts and consists of laminated or multi-ply board made up of a series of thin sheets of cardboard glued or otherwise secured together, It is, of course, apparent that any suitable heat insulating material may be employed for this purpose. This insulating wall 10 is held in position by a series of vertical wood bars, indicated at 11 in Fig. 1. The pasteboard or insulating walls are preferably treated with any well known moisture repellant especially where exposed to moisture to prevent absorption of moisture by them.

Within this outer cabinet is an inner double wall cabinet mounted upon a suitable heat insulating support, such as the foundation piece 12 preferably made of cork. This inner cabinet comprises an outer wall composed of the upper and lower portions 14 and 13, respectively. As is clear from Fig. 9, the upper portion 14 is made of metal, while the lower portion 13 is made of a suitable heat insulating material, such as building pasteboard. These two walls are mounted in alignment, as is clear from Fig. 9. An inner wall is similarly constructed with the parts reversed so that the upper wall is constructed of building pasteboard and the like, as indicated at 17, and the lower wall is a portion of a metal container 40. These walls 17 and 40 are likewise in alignment, as clearly shown in Fig. 9. It will be noted that the planes of the abutting edges of these walls are vertically displaced.

In the region of the joints between these walls there is provided a suitably shaped wall 22 of heat insulating material which fits tightly between the inner and outer composite walls, as is again clearly shown in Fig. 9. This wall 22 is provided with holes therethrough at the top-and bottom, as is clear from the drawings. Extending upwardly from the wall 22 is an inner wall of heat insulating material 16, and extending downwardly therefrom is the heat insulating wall 21. These walls 16 and 21 divide the space between the composite walls into two chambers.

.As is clearly indicated again in Fig. 9, these chambers are filled with cotton fibres, as indicated at CF, which extend transversely between the walls and are preferably glued at their points of contact with the walls. These cotton fibres provide a heat insulation which is pervious to slow gas filtration. `The composite walls in association with the wall 22 provide closed chambers, as will be apparent from Fig. 9, which are not open to the space to be refrigerated outside of the inner cabinet, nor open to the space within the inner cabinet which receives the refrigerant. These closed chambers are, however, open to the space between the double walls of the inner container. At this point it should be noticed that there is one of these closed chambers on each side of the square inner cabinet.

Mounted on the lower end of the wall 16 on each side is a metallic disc 43 which is secured thereto in any suitable manner. Mounted in these discs are the pins 44 which are provided at their inner ends with reduced threaded portions on which the thermostatic conducting arm 25 is mounted. 'I'he pin is provided with a tool receiving head so that it may be rotated.

'Ihe thermostatic heat conducting arm 25 is shown provided with an angle piece 41 riveted to the lower end, and a plate 42 likewise riveted at the other end and provided with a threaded opening so that it may be mounted on the threaded stud of the pin 44. Mounted on the inner wall 40 on each side of the arm 25 are the stops 50. With this arrangement it is possible to adjust the relative position of the arm 25, and particularly its contact piece 41 with respect to the wall 40, so as to move it towards or away from the wall by rotating the pin 44. The stops 50 prevent rotation of the arm-25. The contact piece 41 is connected to the lower end of wall 16 by means of heat conductors 26. These heat-conductors are preferably soldered or brazed to the contacts 41 and the wall 16 so as to make good heat contact therewith. They are constructed of good heat conducting metal, such as copper, and are preferably made of strands of copper wire or ribbon. They are thus constructed in order to give maximum flexibility so as not to materially interfere with the movement of the heat conducting arms 25. The heat conducting arms 25 are made of suitable metals to provide a bi-metallic thermostatic structure which will warp or bend under heat changes. Such bi-metal thermostats are exceedingly Well known in the arts and need 1 not be descrbed in detail.

To insure a rigid structure for the inner cabinet the inner and outer walls are held in spaced relation by means of the vertically extending spacer bars 20, as is clear in Fig. 1. The refrigerant cabinet is closed by means of a closure or cover 28 between which and the ice there is preferably placed a suitable heat insulated body 30. As indicated in Fig. 2, the blocks of solid refrigerant are shown at 31. It should be noted here that only the lower block is in contact with the metal container 40, while the upper blocks are in contact with the insulating wall 17.

The space to which the refrigerant itself -is supplied is connected to the spaces between the double walls of the inner cabinet by means of a perforated tube 19 so that the gas formed may escape in the space between the double walls of the inner cabinet. Likewise, the space between the double walls of the inner cabinet is connected to the space between the double walls of the outer cabinet by a tube 18 which is perforated at its ends as shown. The space between the double walls of the outer cabinet is connected to the atmosphere through a passage 35, as shown in Fig. 6. This passage is controlled by means of a valve structure which is shown in full detail in Figs. 4 and 5. It comprises a cupshaped box 34 provided with a hole therethrough, as indicated at 35, which is in alignment with the passage 35a when mounted in operative position.

Secured in this cup-like member by means of a screw'37 is a thin fiexible metal arm 36 which normally closes the hole 35. A cover 38 is provided for the cup 34 having several holes 39 therein, as is clear in Fig. 4. When the gas pressure within the double walls is sufficient to raise the flexible arm 36 the gas may iiow therefrom into the atmosphere until the arm 36 again closes the passage. Thus, gas generated by the refrigerant flows through tube 19 into the space between the double walls of the.inner cabinet and after circulating therethrough ows through pipe 18 to the space between the double walls of the outer cabinet. FI'Qm this space it slowly escapes into the atmosphere. The spaces between the double walls of both cabinets are filled with cotton fibres, as previously described, and as indicated in Figs. 6 and 9. This cold carbon dioxide gas permeates the space between the double walls of both cabinets and slowly filters through the loosely packed cotton fibers on its watI to the atmosphere. Although the cold carbon dioxide gas is of little refrigerating value it acts as an eillcient heat insulator against the entrance of heat into the refrigerator because of its poor heat conducting qualities. As indicated in Fig. 6, this gas may likewise filter in and permeate the granulated cork fllling 15 between the bottom walls of the two cabinets. This is accomplished by providing passages 4 in the members 4 covered withscreens 4b.

In the operation of the device the inner cabinet is charged with ice, as indicated in Fig. 3, and the space surrounding the inner cabinet and within the outer cabinet is filled with the materials to be refrigerated. As the temperature in the space to be refrigerated rises, the wall 14 likewise rises in temperature and so does the bi-metallic arm 25 which is connected thereto. When a predetermined temperature is thus reached the bi-metallic arms flex to a position so that the contact pieces 41 engage the wall 40. 'The temperature at which this will occur may readily be controlled,

first, by the selection and proportions as to size of the bi-metallic arms 25, and, second, by its position with regard to the wall 40. Its position may be adjusted, as previously described, by rotating the pins 44. Thus, the nearer the contact pieces 41 are to the wall the less temperature change will be required to effect connection and disconnection therebetween. Or, when the bimetallic arms flex to effect this connection the heat in the space to be refrigerated may readily flow through walls 14, discs 43, conductors 26, contacts 41, and wall 40 to the refrigerant directly in contact therewith. As heat is abstracted from the space to be refrigerated its temperature falls and this continues until the bi-metallic member moves back so as to break the connection between the wall 40 and the contacts 41. It is, of course, apparent that the bi-metallic members 25 will likewise change in temperature, as described, because of their direct metallic contact with the walls 16. Thus by proper adjustment of the apparatus the temperature in the space to be refrigerated may be accurately maintained between relatively .narrow limits.

At this point it should be noted as an `important feature of this invention that the bi-metallic arms 25, which might be termed heat switches, are entirely enclosed and are particularly protected against the atmosphere of the space to be refrigerated. They are,l of course, open to the space between the double walls of the inner cabinet so that the gas which permeates this space will likewise flll the chambers within which the heat switches are mounted. 'This is an important feature because it prevents the condensation and freezing of any moisture present in the outer cabinet on the parts of the heat switch which, if it occurred, would seriously interfere with the correct operation thereof. The fiowof cold dry carbon dioxide gas through the switch chamber evaporates, picks and carries away the frozen condensate.

From the above detail description it will be apparent that this invention resides in certain principles of construction and operation which may be embodied in other physical forms without departure therefrom. Hence I do not desire, nor intend, to be restricted to this disclosure, as given for purposes of illustration, but rather to the scope of the appended claims.

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

l. An apparatus as described comprising a double wall container to provide a storage space. a double wall receptacle mounted within said container to receive solid carbon dioxide, a connection between the receptacle and the double walls thereof to permit carbon dioxide gas to escape into the double walls of the receptacle, a connection between the double walls of the receptacle and the double walls of the container to permit carbon dioxide gas to enter the double walls of the container, and a valve controlled exhaust port for controlling the escape of gas from the double wall container.

2. A refrigerator as described comprising a double wall cabinet, a double wall receptacle within said cabinet provided to receive 'solid carbon dioxide, a gas connection between the interior of the receptacle and the double walls thereof, a pipe connection between the double walls of the receptacle and the double walls of the cabinet, walls forming with the double walls of the receptacle a closed chamber, a thermostat arm mounted within said chamber, heat collecting members connected to said thermostat and exposed to the space within the o uter cabinet, and a metallic wall positioned to b'e in contact with the solid refrigerant within the receptacle, said thermostat arm being positioned for establishing thermal connection with said metallic wall.

3. A refrigerator as described comprising a double wall cabinet, a double wall receptacle within said cabinet provided to receive solid carbon dioxide, a gas connection between the interior of the receptacle and the double walls thereof, a pipe connection between the double walls of the receptacle and the double walls of the cabinet, walls forming withv the double walls of the receptacle 'a closed chamber, a thermostat arm mounted within said chamber, heat collecting members connected to said thermostat and exposed to the space within the outer cabinet, and a metallic wall positioned to be in contact with the solid refrigerant within the receptacle and to be contacted by said thermostat arm to establish thermal connection therewith, the walls forming said chamber having openings therein so that the chamber is in communication with the double walls of the receptacle.

4. In an apparatus of the character described comprising an outer container, an inner container, an inner container adapted to hold solid carbon dioxide and having a space between the containers, means for conveying the carbon dioxide vapor from the inner container to the space between the inner and outer containers, and a thermostatic arm mounted by one end upon the outer container in thermal contact therewith and positioned upon flexure to engage the inner container to effect thermal contact therewith, said arm being in the space between the inner and outer containers and subjected to the carbon dioxide vapor therein to prevent the accumulation of frost thereon.

JU STUS C. GOOSMANN.

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