US2150181A - Refrigeration - Google Patents

Description

March 14, 1939. c. G. MUNTERS REFRIGERATION Filed March 31, 5 sheets-sheet 1 I IIIIIIIIIIIIL INVENTOR .7 ATTORNEY March 14, 1939.

c. G. MUNTERS REFRIGERAT ION Filed March 5l, 1934 5 sheets-sheet 2 March 14, 1939. c. G.' MuNTx-:Rs

REFRIGERATION Filed March 3l, 1954 5 Sheets-Sheet 5 /l NVENTOR 147 M WJ ATTO RNEY

March 14, 1939. C. G, MUNTERS 2,150,181

REFRIGERATION Filed March 5l, 1954 5 Sheets-Sheet 4 w /l 68 l 6? INVENTOR March 14, 1939. Cl G. MUNTERS 2,150,181

REFRIGERA'TION Filed March 3l, 1934 5 Sheets-Sheet 5 i7 O I I INVENToR Patented Mar. 14, 192.9v

UNITED STATES 2,150,181 REFRJGERATION Carl Georg Munters, Stockholm, Sweden, assignor to Aktiebolaget Termisk Isolation, Stockholm, Sweden, a corporationl of Sweden Application March 31, 1934, Serial No. '718,392

In Sweden November 16, 1933 My invention relates to refrigeration and more particularly to the conservation of cold produced by a refrigerating apparatus or the like.

One of the objects of my invention is to provide a refrigerator having a light, sturdy insulation.

Another object of my invention is to utilize the cooling effect of the primary cold producer to prevent condensation in insulation. In this connection, I produce a circulationl of air in the insulation in a manner as hereinafter set forth.

The nature and advantages of my invention will be understood from the following description taken' in conjunction with the accompanying drawings forming part of this specification, and of which:

Fig. 1 is a vertical cross-sectional view of a refrigerator embodying the invention, and is taken on the line I-I, of Fig. 3;A

Fig. 2 is a view of part of the structure shown in Fig. l on larger scale;

Fig. 3 is a vertical cross-sectional view takenon the line 3-3 of Fig. l;

Fig. 4 is a horizontal sectional view taken on the line 4 4 of Fig. 3;

Fig. 5 is a horizontal sectional view taken on the line 5-5 of Fig. l;

Fig. 6 is a plan view of a sheet of cardboard before bending, forming part of structure shown in other figures;

Fig. '1 shows another piece of cardboard;

Fig. 8 shows a modified form of the construction shown in Fig. 5; and Fig. 9 shows a detail. The refrigerator includes a cabinet which inand having flanges II which are secured to a k frame member I2 as by screws I3. Frame meme ber I2 may be made of wood. 'Ifhe lining I Il is made of sheet steel and may be porcelained. It

vertical wall through which part of the refrigerating apparatus is inserted. The lining forms the border of the food space I5 of the refrigerator.

the frame member I2. The outer shell may be made up of a plurality of plates welded or otherwise secured together. Angle irons I'I may be provided at the corners to which the plates are secured. A refrigerator apparatus compartment is formed back of sheet I6 by suitable plating.

Between the inner and outer shells III and I6 are spaced cardboard boxes. In the embodiment shown, threesuch boxes are provided. 'I'he number may be more or less depending on the temcludes an inner shell or lining I0 open at the front is also provided with an opening I4 in its back- An outer insulation Shen 'I6 is also secured to perature diierential to be maintained between the food space I5 and the surrounding atmosphere 0r space. The three boxes or containers are designated IB, I9 and 20. These boxes are similar and the description of one will suffice. I

Box I8 is essentially a five-sided cardboard box open at the front of lthe cabinet having sheets 2I of aluminum foil pasted or otherwise disposed on each side. Other material having bright surface for heat reection' may be used but the most readily obtainable at the present time is sheets of aluminum of, for example, 0.00'1 millimeter in thickness.

The box is formed from sheet cardboard and can be advantageously made up from pieces as shown in Figs. 6 and '1. A sheet of cardboard, which may be, for example, of the kind having smooth outer sheets and an intermediate corrugated sheet, and having a thickness of, for example 1/8 to 11g inch, is notched as shown in Fig. 6 and bent along the lines 22, 23 and 24 to form three sides of the box. An opening 25 is cut in the middle section to be in line with opening I4 of the liner and flanges 23 for this opening are formed by cutting on the lines 21 and folding on the dotted lines 28.. Side flanges 30 are formed by bending along the dotted lines 29. Side pieces or panels 32 of cardboard are then pasted to the flanges 30, thus forming the flve sided box. Flanges 3| are provided at the open side of the box thus formed. These are bent over on the dotted lines 33.

On mounting the cardboard box in the cabinet. these anges 3l are secured to the frame member I2 as by nails 3l. Preferably strips 35 of cardboard are glued onto the frame member I2 and the flanges 3| glued or cemented onto the card# board strips 35 as well as secured by nails. It is also preferable to glue or cement pieces of paper or cloth over the meeting edges of pieces 32 and` flanges 30. The boxes are to be tight at these edges andalso tight where secured to the frame member I2. When mounted, the flanges 23 are glued or cemented to a cardboard collar 31 aligning the openings at the back of the cabinet for the refrigerating unit. The collar 31 is made tight with the liner as by being flanged at 38 land glued or cemented to the liner. Collar-31 is secured to the outer shell as by being flanged at 40 and pressed between the outer shell and a ,wooden frame 4I by screws I2. Cement, glue -or other tightening means may also be here applied.

The sheets of. metal 1011 are pasted on veach j side of the cardboard boxes. No foil is, however, pasted on flanges 3| or 23.

The cardboard boxes with their bright metal surfaces are nested within each other to provide air spaces 46, 41, 48 and 48. 'Ihese air spaces are tight against; leakage of air except for cer- 5 tain holes hereinafter specied. The boxes may be spaced a distance of, for example, 2 to 2.5 centimeters (about 3A to 1 inch).

Sheets of aluminum foil 50 and 5I are also pasted or glued onto the outer surface of the liner I 0 'and the inner surface of the outer shell I6 respectively.

The refrlgerating apparatus includes an evaporator 52 mounted on a pipe or heat exchanger 53 passing through an insulated wall part 54 which ts into the openings at the rear formed in the inner and outer sheets and the cardboard boxes. The member 53 is connected to that part refrigerating apparatus |53 which is outof the side the insulated food space. The type of refrigerating apparatus is immaterial.- It may be of the compression type or the absorption type with any desired form of heat input, as for example a burner |54. Other sources of cold may also be used such as ice or solidied carbon dioxide. With certain types of cold producers, the opening in the rear is not necessary. The type of apparatus may be that shown in Pats. No. 1,609,- 334, 1,910,853 and 2,037,782.

Where a removable wall section such as 54 is used, it may be made as a slab of cork .havingv an inside plate 55 and an outside plate 56. To provide tightness, a gasket 51 is mounted on an outturned ange 58 on the liner against which plate 55 bears and a gasket 59 is provided between plate 56 and the outer shell.

The door is constructed in similar manner. It includes an outer shell 60 secured to a wooden frame member 6I. Awooden frame member 62 is ysecured to member 6I. A sheet of metal foil 63 is glued or cemented to the inside surface of shell 60. A sheet of cardboard 64 with sheets of metal foil on each side thereof is placed against frame member 6I which spaces it from member 60 by, for example, three fourths of an inch.

A box 65 is made with sides 66 which are nailed or glued, or both, to member 62. 'I'his member is coated with metal foil except for the sideanges 66. One or more additional such boxes 61 may be inserted. An inner door shell 68, coated with metal foil on the side toward box 61 sets into a rubber gasket 69 and is held in place as by screws fastened vinto member 62. Parts 62, 65 and 61 may be, for example, a separate subfassembly.

Suitable tightening means such as a metal strip 88 fastened to the door and bearing against a ber strip 89 fastened to member I2 may be'employed between the door and the outer shell I6. The spaces between the parallel cardboard pieces in 60 the door may be on the order of 1 inch. Less spacing, as shown, may be used but obviously the Wider the spacing, the less the material for a given door width. This spacing is hereinafter more fully discussed. d

For the purpose of preventing condensation within the insulation, I provide means for circulation of air. A pipe Ill is provided extending through the closure or panel 54 affording direct communication between the outer atmosphere 70 and the food space. In the embodiment shown, this pipe is of 5 millimeters inside diameter. In the lining I0 is a hole or port'1I somewhat above the bottom of the food space. This hole, in the embodiment shown is of 8.millimeters diameter., 75 In the center top of boxhI is a 10 millimeter hole 12. In the bottom center of box I9 is a 10 millimeter hole 13. In the bottom of box 20 to one side of the hole in box I9 is a 10 millimeter hole 15. The outer shell is similarly apertured as at 16.

By means of these apertures, a very slow circulation of air is produced from the outside atmosphere through pipe 10 into the space I5, thence through hole 1I into space 46, thence through hole 'I2 into space 41, thencethrough hole 13 into space 48, and through holes 'I5 and 16 back to the outer atmosphere. The air passing into the space I5 is cooled to the lowest temperature. 'Ihe cooling should be such that on subsequent flow through the spaces of the insulation, condensation does not occur. A natural circulation is set up in the aforesaid direction4 twice the recommended spacing without having serious convection currents in the intervening air spaces. The spacing can be, for example, 2 to 2.5 centimeters, or 3A to 1 inch. At these spacings, convection currents will take place Abetween the vertical walls but I have determined that with the insulation herein described, advantages are obtained which more than offset losses due to the small convection movement of the air. It is particularly difficult to build up a suitable structure for holding unbacked metal foils in an irregular wall structure as in a refrigerator. The frames l conduct heat and are expensive if made so as to prevent losses in the frames. By using seifsupporting boxes, I avoid corner frames and I avoid transverse conduction at the corners, and I entirely avoid intermediate spacing members which would conduct heat. Furthermore I provide 'equal temperature spaces around the food space separated from each other except at the front frame.V This makes it possible to provide a slow, uniform air circulation throughout the insulation. With separate overlapping packages, heat conducting paths are formed and, to

lhave a proper circulation, connections between the packages would be necessary, which is complicated.

Condensation in insulation of a refrigerator is a difficult problem. Condensation takes place when air is cooled so that moisture precipitates therefrom. It is therefore desirable that air does not flow from the atmosphere through the insulation to or toward the food space. To prevent this, I make use of a preponderance of weight between columns of air to force circulation of air outwardly through the insulation so that condensation cannot take place within the insulation. I conduct air into the food space so that it is first coooled and moisture may therefore deposit out in the food space. 'Ihus I ensure dry air passing through the insulation and prevent moisture which would corrode the metal surfaces and otherwise harm the insulation and detract from the insulation properties. Since I use very few layers, it is important that they shall' not have a lm of water on them,

u and having a lower liquid sealed opening in a drip amarsi The door spaces may `likewise be provided with means for ow of air outwardly from the food space although a door can readily be made tight with respect to the outer atmosphere and forced air circulation isnot of such importance as in the cabinet itself. As an example, a hole may be provided in plate 88 at the level of hole 1 I a hole may be provided in member 61 at a high part thereof, a hole in member 65 at a low part thereof, a hole in member 64 at a high part thereof, and a hole in the bottom of member 60. In some instances, natural leakage may be relied on instead of holes but I prefer definite lholes with the spaces otherwise air-tight so that a positive controlled circulation may be obtained. The holes should be of suillcient size to provide adequate circulation to prevent condensation but so small as to prevent appreciable loss of cooling effect due to the flow.

-The aperture into the food space may advantageously be higherthan the aperture between the food space and space 46 so that a cold down-leg is assured and the supply of the air to the food space can advantageously be through the rear window adjacent the evaporator so that good coolingof the air is obtained.

However, the openings may be 4arranged kin la variety of ways so long as the outward movement is assured. The holes should be arranged to give a preponderance of specic gravity of air column so that the flow is directed from the inside to the outside. It is preferred to so arrange the holes that there is movement of air all around the refrigerated space. By means of the nested box construction I am able to provide a path of ow of air which entirely encompasses the refrigerated space.

'I'he air need not circulate entirely through the insulation but may circulate from the food space, downwardly in the first outer space, upwardly through a second outer space bf higher temperature and back to the food space for drying by cooling.

'I'he hole 1| is preferably positioned so that water will noty enter the same on washing out the interior of the refrigerator. It may be placed, as

shown, on a shelf supporting projection in thel liner.

Another door construction is shown in Fig. 8

in which cardboard boxes 80 and 8| are nailed and/or glued, together with member 64, onto the frame member 8|. This door construction includes a Bakelite frame 82 and rubber gasketing I3. Long screws may pass through plate 68 and into member 6|. It will be seen that I provide a light door construction which is easy to build.

It will be seerr that the amount of material necessary to handle for making the insulation is small. Sheets of cardboard and aluminum foil can be stored in small space and readily formed in the process of manufacture.

Fig. 9 shows a moisture separator which may be inserted in the aperture 1i. It includes a casing 98 having bailles 9| therein and an end piece 92 having a central opening. Bafiles 9| are apertured to provide a tortuous path for gas and cut at their lower parts to allow separated moisture to flow into the food space I5. v

Instead of having the opening 15 in the bottom of box 20, this opening may be higher up or at the.

top so that complete circulation takes place through all the air spaces.

The pipe 10 may be arranged to extenddownwardly for some distance within the food space pan and a branch connected to space l5 whereby the air is cooled and dehydrated due to the cooling source and lad directly into space 46.

It will be noted that an important factor is that air shall not pass inwardly through the insulation to or toward the food space. 'Ihe outside shell of the insulation can be made tight, but even in such case it is advantageous to have a cold air column acting against the outside shell to allow breathing of the insulation due to barometric variations or otherwise without condensation and to guard against unintentional leaks.

It will be understoodv that the invention is not limited to the embodiment disclosed and that many variations are ,possible within the scope and spirit of the invention.

What I claim is: 1. A refrigerator having a framework, an inner liner attached to said framework, an outer shell attached to said framework, and intermediate cent one of said boxes, said boxes being surfaced 2. A refrigerator having an outer shell, an in ner liner spaced therefrom, said outer shelland said liner being open on a common vertical side to provide a door opening, a plurality of nested, light, non-metallic self-sustaining box-like members between said shell and said liner, closure means between the liner and shell and members at said vertical side, .said members being appreciably spaced from each other and from the liner and from the outer shell, said members being surfaced with bright metallic layers and surrounding all walls of the liner whereby intermediate spaces having both horizontal and vertical portions are formed between fthe liner and the outer shell, ,said liner having an opening in its lower part forming an air ow passage between the interior space of the liner and a first intermediate space and said members having additional openings at different elevations whereby air circulation is produced due to difference of specific weight of different vertical air columns and air circulation is induced in the horizontal portions of the intermediate spaces due to the vertical columns of different specific weight.

3. A refrigerator having an outer shell, an inner liner spaced therefrom, said outer shell and said liner being open on a common vertical side to provide a door opening, a plurality of nested, light, self-sustaining rigid cardboard box-like members between said shell ,and said liner, closure means between the liner and shell and members atsaid vertical side, said members being spaced from each other and from the liner and from the outer shell on the order of one half an inch to an inch, said members being surfaced with bright metallic layers and surrounding all walls of the liner whereby intermediate spaces having both horizontal and vertical portions are formed between the liner and the outer shell, said liner having an opening lin its lower part forming an air ow passage between the interior space of the liner and a first intermediate space and said members having additional openings at different elevations whereby air circulation is produced dug to difference of portions ofthe intermediate spaces due to the vertical columns of different specific weight.

4. A refrigerator having an outer shell, an inner liner spaced therefrom, said outer shell and said liner being' open on a common vertical side to provide a door opening, a plurality of nested light, non-metallic self-sustaining box-like members between said shell and said liner, closure means between the liner and shell and members at said vertical side, said members being appreciably spaced from each other and from the liner and from the outer shell, said members being surfaced with bright metallic layers, said liner having an opening forming a communication between the interior space of the liner and a first intermediate space and said members having additional aper.- turing whereby air circulation is produced due to diierence of specific weight of different vertical air columns.

5. A refrigerator having an outer shell, an inner liner spaced therefrom, said outer shell and said liner being open on a common vertical side to provide a door opening, a framework at the edges of and connecting the outer shell and the liner, a plurality of nested, light, self-sustaining cardboard box-like members between said shell and said liner attached at their edges to said framework, said members being appreciably spaced from each other and from the liner and from the outer shell, said members being surfaced with bright metallic layers and surrounding all walls of the liner whereby intermediatey spaces having both horizontal and vertical portions are formed between the liner and the outer shell, said liner having an opening in its lower part forming an air ow passage between the interior space of the liner and a rst intermediate space and atleast some of said members having openings at different elevations whereby air circulationis produced due to difference of specific weight of different vertical air columns and air circulation induced in the horizontal portions of the intermediate spaces due to the vertical columns of different specific weight.

6. Refrigerator cabinet construction comprising an outer shell, a plurality of self-sustaining boxlike structures nested one Within the other, said plurality of boxlike structures being formed of poor heat conducting material and mounted in the.

outer shell in spaced relation to the walls thereof, a liner inwardly of the innermost structure constructed to form a food storage compartment, certain of said structures having a surface of a nature to obstruct iiow of heat through the structure towards the center of the cabinet, and means for restricted air communication between the storage compartment and spaces adjacent said boxlike sustaining and being surfaced with metallic reflective material to hinder loss by radiation, and means for restricted air communication between said compartment and space adjacent said insulating unit.

8. A device of the class described comprising inner and outer shells, insulating means between said shells comprising a plurality of preformed spaced self-sustaining boxlike structures of aluminum surfaced cardboard nested one within the other and means for restricted air circulation in spaces between the said boxlike structures.

9. Cabinet construction comprising a door frame, a self-sustaining heat flow obstructing insulating unit mounted on said door frame comprising a boxlike structure formed of non-metallic poor heat conducting material and having a metallic heat reflecting surface.

10. Insulation comprising a plurality of preformed generally box shaped heat ow obstructing units nested in spaced relation and having walls of self-sustaining non-metallic poor heat conducting material provided with metallic heat reflecting surfaces.

11. Insulation for use with walls forming an enclosure to retard heat flow through the walls of said enclosure comprising a self-sustaining heat ow obstructing insulating unit in the form of a boxlike structure composed of non-metallic poor heat conducting material and having a metallic reecting surface.

12. A device of the character described comprising walls forming a compartment, means for insulating to retard heat flow through said walls comprising a series of nested preformed insulating units about said compartment disposed in separated relation to provide intermediate air spaces, and means forproducing circulation of air outwardly from the compartment between said nested units whereby moisture condensed within said nested units will be carried outwardly to the atmosphere.

13. Refrigerator construction comprising walls forming a storage compartment, spaced nested insulating units about said compartment providing air spaces, cooling means within said compartment, means for permitting breathing between said compartment and said air spaces, whereby incoming air will be cooled due to the cooling means in said compartment and thereby reduced in moisture content and such dried air may take up moisture as it flows in the air spaces provided by said nested insulating units.

14. Refrigerator construction comprising walls forming a storage compartment, spaced nested insulating umts about said compartment providing air spaces, cooling means within said com- I partment, means for permitting breathing between said compartment and said spaces, whereby incoming air will be cooled due to the cooling means in said compartment and thereby reduced in moisture content and such dried air may take up moisture as it flows in the air spaces provided by said nested insulating units, the construction being such that air ow is over a substantial portion of the insulation.

15. Refrlgerating construction comprising walls forming a storage compartment, spaced nested insulating units about said compartment, cooling means within said compartment, means for admitting air directly into the compartment in the vicinity of the cooling means, and means for discharging air from the compartment through said nested units in a circuitous path to take up moisture from said insulating units.

CARL GEORG MUNTERS.

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