US1993328A

US1993328A - Refrigerating apparatus for the storage and preservation of food, delicacies, and the like

Info

Publication number: US1993328A
Application number: US682692A
Authority: US
Inventors: Ingvardsen Johan Freder Ingvar; Levring Erik Anders Dalsgaard
Original assignee: Individual
Current assignee: Individual
Priority date: 1933-01-28
Filing date: 1933-07-28
Publication date: 1935-03-05
Anticipated expiration: 1952-03-05
Also published as: GB418934A; CH173158A; US1993325A; GB417219A; AT142061B; DE615172C; AT140038B; DE619333C

Description

March 5, 19 35.

REFRIGERATING APPARATUS FOR THE STORAGE AND PRESERVATION l. INGVARDSEN El AL 1,993,328

OF FOOD, DELICACIEYS, AND THE LIKE Filed July 28, 1935 FIG/7 Patented Mar. 5, 1935 UNITED STATES PATENT OFFICE Y REFRIGERATING APPARATUS FOR THE STORAGE AND PRESERVATION OF FOOD, DELlcAClEs, AND THE LIKE Application July 28, 1933, Serial No. cacsz In Denmark January 28, 1933 12 Claims.

The invention relates to a refrigerating apparatus for the storage or preservation of food, delicacies and the like. l

The use of such apparatus is at the present time increasing progressively,-both for household purposes and for use in shops and the like, and indeed to such an' extent that such apparatus must be regarded already as indispensable for shops of a certain type. A disadvantage associated with'the apparatus of known type in the last-named sphere of application is, however, that it is not at the same time suitable for showing or displaying the goods, because the apparatus is always in the form of closed cabinets (refrigerators), which is easy to understand in view of the fact that a good heat insulation is necessary.

In order to overcome this drawback, special refrigerators are already'made for show windows and for other display purposes. The walls of these refrigerators are of glass and quite transparent. In order that the necessary heat insulation may be obtained in this construction it is necessary to use at least three glass plates, arranged one behind the other, for each wall.

The glass plates can then, however, easily be- Finally, all known forms of construction of refrigerating apparatus such as mentioned above are expensive, especially also owing to cabinet structure itself.

According to the present invention, all these disadvantages are overcome owing to the fact that the part of the refrigerating apparatus which gives off the cold is constructed as a surface located freely in space on which the goods to be cooled can be placed so as to be freely exposed to view, and the cooling capacityof theapparatus is so great that the temperature of.

the surface which may be made in any suitable form can be kept so low that white frost is formed thereon. I

Itwill be evident that the said surface may be used directly for instance as a table, display board, or the like. The appearance of such a surface is rendered particularly attractive by the valuable, particularly in many shops, restaurants white frost of course is always kept at at least 0 C., it is also possible to produce freezing in a simple manner. Whipped-cream tarts when placed directly on the cooling surface, and in certain cases preferably on a metal dish, freeze on the lower side and thus retain a firm base, and thus the disintegration which is so unpleasant is prevented.

In a typical embodiment of the invention the surface which gives off the cold contains chanrator of a compressor refrigerating plant or a guideway for a refrigerating medium (brine, for instance a solution of sodium chloride).v When used as a table, display board or the like, the under side of the plate including the channel this apparatus has the great nels, pipe-coils or the like which form the evaposystem is preferably covered by a layer of heat insulating material and enclosed with it in a frame so as to produce a good insulating effect.

The frame, made for instance of metal, should Various forms of construction of the invention are illustrated in the annexed drawing, in which:

,Fig. 1 is a diagrammatical representation of a cooling apparatus according to the invention which operates with a compressor- Fig. 2 shows a plan of a cooling plate used therewith.

Fig. 3 shows a method of attaching a pipecoil conducting the cooling agent to the surface plate.

Figs. 4, 5, 6 and '7 are cross sections of various forms of construction of the frame embracin the cooling plate and the appropriate method of by a water cooler, in which case the fan 4 mostly may be omitted. The gas (SO2,NH3 or the like),

condensed by the compressor, passes through the piping 6 into the cooler 5, from there passes through the piping 7 and then arrives in the expansion valve (throttling nozzle or the like) 8. In the cooler 5 the gas shouldbecondensed to a liquid.- The gas expands in the expansion valve 8 in known manner, thus producing cold which is given off to the plate 9. The expansion valve 8may, of course, be constructed in various manners and may, for instance, alsobe self-regulating. In this case the adjustment can be controlled either by the gas pressureor by the temperature of the plate 9. After the working medium has given off its cold, it flows through the piping 10 to the suction side of the compressor. The piping 10 is of such length, if necessary arranged in one or more coils 11, that the working medium is always able, even when the temperature of the surroundings is low, to give off its excessive cold to the surrounding air, (when this cannot be done completely by the plate 7) before it again reaches the compressor 3. At the same time it is thus also possible to give the plate an inclined position, for instance, because the pipes can then yield sufliciently to permit it.

In-Fig. 1 the plate 1 is surrounded by a frame 12 which is insulated from the plate and thus cannot assume a low temperature. The frame extends above the plane of the plate 9 to serve as a border or rim which sharply delimits the frosted area that forms upon the refrigerated plate.

Fig. 2 shows how the piping coming from'the expansion valve. may be arranged under the plate 9. The piping enters at 13 and then runs in bent formation along the lower side of the plate 9. The piping 10 leaves at 14. It is recommendable to combine the points 13 and 14 in such a manner that only one opening need be made in the table. It is much easier then to make the tubes fit airtight in the opening, which is very necessary as will be pointed out hereafter. It is, of course," important that the pipe coil under the plate 9 should be in good thermally conductive connection with the said plate 9. This can best be done by soldering or welding (for example spot 'welding) when the pipe coil'is made as a sepa- 3. Here, for instance the pipe 15 is soldered to the plate 9 by means of an ample proportion of an I alloy of low melting point (for example Woods or Roses metal). The advantage of such an alloy is that the soldering can, for instance, be carried out by immersing the plate in hot water. With this-low temperature one may be sure that no buckling, warping or other deformation of the plate 9 can occur, which is very important as naturally the plate 9 must be kept as fiat as possible.

It is evident that it is also possible by means of the refrigerating plant to cool a solution of sodium chloride or the like to, for instance, 15 C. below zero, and then cause this solution to run along the bottom of the plate 9 or to circulate therein. there is therefore a certain accumulation of cold available, and it is then also possible to fit the plate 9 on already existing refrigerating plants. Moreover, the latter is possible in any case- Fig. 4 shows how the plate 9 can be secured in the frame 12. On the upper side this plate 9 is surrounded, for instance, by a strip of rubber 16 (in some cases for instance also by a rubber tube filled with cork) against which the plate 9 is pressed by means of thescrews 1'7. Immediately against the underside of the plate there are disposed small strips 18 of cork, supported by small strips 19 of wood, against which small plates 20 of fibre, bakelite or the like are pressed. The screw 17 co-operates with a nut 21, likewise made of insulating material such as fibre or the like. exactly adjusted, while a very great resistance is offered to the transmission of heat between the plate 9 and the frame 12. The resistance is further increased in that the plate 9 is allowed to come into-contact with the rubber 16 and the cork 18 only along a very narrow edge.

The space below the plate 9 and therefore about the pipe coil 22 is filled with an insulating mass lower side. It is of importance of course, that no air can enter into the space between the

plates

9 and 24, because if there would arise some air circulation, also white frost would be formed there and this would decrease the cooling action at the upper side considerably, while besides a lot of condensation water could be formed within the insulating mass. Owing to. its large surface the frame 12 can easily assume the' temperature of the surroundings, and therefore does not become covered with white frost, and does not even become coated with moisture.v Preferably, the plate 9 is coated with nickel and then sanded, while the frame 12 may be coated with chromium, so that a very bright appearance is got together with the layer of white frost. The frame 12 is best made in the manner of extruded metal. The spe- In this manner the plate 9 can be t tion. In this case the plate 9 is clamped between two strips of

rubber

25 and 26, which are held in place by small blocks of wood 27, cork plates 28 being interposed if necessary.

Fig. 6 shows a further form of construction. Here also the plate is clamped between two strips of

rubber

29, 30. In this arrangement the plate 9 can again be adjusted by means of screws 31. Further the rubber is as far as possible entirely enclosed at the upper side by an overturned edge extended beyond this cabinet.

32 of the frame and at the lower part by a corresponding overturned edge 33 of the bearingplate of the screw 31. In this manner the rubber is removed from'sight as far as possible, and exposed as little as possible to the action of moisture, while the heat transmission between the plate 9 and the frame 12 is not substantially increased by the contact of the

overturned edges

32 and 33 with the plate 9, such contact being not more than a point-to-point one.

Fig. '7 shows a construction in which all the component parts are of bent metal. It is suitable for use, for instance, when rustless steel is used for the frames. The insulation is in the form of a rubber cord 34. In other respects the figure speaks for itself.

An easy manufacture of the plate is obtained if the surface plate 9 is given round corners. Then an endless strip of rubber provided with a groove is disposed under slight tension around the edge of the plate 9. The frame 12 may consist in this event of two parts, each of which is adapted to be thrust sideways over the plate, a groove in it surrounding the rubber strip. Thereafter the two parts may be attached together, and then they form a stiff frame in which the plate 9 is supported.

It may be added that the refrigeratingplates according to the invention may also be constructed,.for instance, as covers of an ordinary refrigerator cabinet, in certain cases as a cover Both the plates and the cabinet can then be operated in a simple manner by the same refrigerating mechanism. In certain cases a change-over device might be provided to connect the refrigerating machine with the refrigerator cabinet and the refrigerator plate as desired What we claim is:-

1. A device for the preservation and display of perishable goods comprising a display surface freely exposed in open air, means for refrigerating said surface, said means being of sufficient capacity to maintain a coating of white froston said surface by moisture withdrawn from air circulating over said surface, a frame surrounding said surface and projecting above the same, and means insulating said frame from said surface whereby the frosted area of the surface is sharply delimited from the unfrosted surface of the frame.

, 2. A device for displaying and preserving perishable goods comprising a display surface freely exposed in open air, said surface constituting the upper member of a body containing passages constituting a conduit for refrigerating medium, a refrigerating apparatus adapted to supply refrigerating medium to said passages in sufiicient quantity to maintain a coating of white frost on said surface, and a frame surrounding said surface and insulated therefrom whereby the frosted area of the surface is sharply delimited from the unfrosted surface of the frame.

3. A device for displaying and preserving perishable goods comprising a display surface freely exposed in open air, consisting of a plate of heat conductive material, pipe coils positioned beneath said surface and in heat conductive relation thereto, a refrigerating apparatus adapted to supply refrigerating medium to said coils in sufiicient quantity to maintain a coating of white frost on said surface, a frame surrounding said I surface and projecting above and below the same,

heat insulating material between said plate and frame, and heat insulating material substantially filling the space below said plate and within the downwardly projecting portion of the frame whereby the frosted area of the surface is sharply delimited from the unfrosted surface of the frame. 1

4. A device as defined in claim 3 wherein said display surface is a metal plate and the pipe coils are soldered to the under side of said plate with a substantial amount of a low melting alloy.

' 5. A device for displaying and preserving perishable goods comprising a display surface freely exposed in open air, means for refrigerating said surface, said means being of sufficient capacity to maintain a coating of white frost on said surface, and a. frame surrounding said surface and sufiiciently insulated therefrom that it will not be chilled low enough to cause the deposition of white frost thereon whereby the frosted area of the surface is sharply delimited from the unfrosted surface of the frame. I

6. A device for displaying and preserving perishable goods comprising a freely exposed display surface, means for refrigerating said sur-- face, said means beingof sufficient capacity to maintain a coating of white frost on said sur-- frigerating medium to said passages in sufllcient amount to 'maintain a coating of white frost on said surface, and a frame enclosing said body and insulating material, said frame being suificiently insulated from said body that it will not be chilled low enough to cause the deposition of hoar frost thereon whereby the frosted area of the surface is sharply delimited.

8. In a device for the preservation and display of perishable goods, the'combination with a substantially air-tight body comprising a frame, a plate forming the upper surface of the body, refrigerating conduits within the body and in heat-transfer relationship to said plate, a layer of heat insulating material within said frame beneath said plate and adjacent said conduits, and means insulating said frame from said plate to prevent cooling of said frame low enough for the deposition of hoar frost thereon, of refrigerating apparatus for supplying a refrigerating mediumto said conduits in quantity sufficient to maintain a coating of white frost upon said plate by moisture withdrawn from air circulating over the same. I

9. A device for displaying and preserving perishable goods comprising a freely exposed display surface, means for refrigerating said surface, said means being of sufiicient capacity to ported in threaded members of insulating ma- 1 terial attached to said frame below said plate.-

12. A device as defined in claim 9 wherein the insulating strip is compressed between the plate forming the display surface and the frame by means of screws bearing on the under side 01 said plate through further insulating material and 7 supported in threaded members attached tosaid frame below said plate.

LTOHAN FREDERIK INGVAR INGVARDSEN. ERIK ANDERS DALSGAARD LEVRING.