US2135181A - Double wall refrigerator - Google Patents

Description

N0v,1',1938. .WJONES 2,135,181

DOUBLE WALL. REFRIGERATOR" Filed NOV. 12, 1934 WALTER Jo/vEs ,QMM 311 A TTORNEY.

INVENTOR.

' Patented Nov 1,1938 1 UNITED STATES DOUBLE WALL nnrmonna'ron Walter J ones,

mesne assignments,

Princeton, N. J.,- assignor, by to Qarrier Corporation,

, Newark, N. J., a corporation of Delaware Application November 12, 1934, Serial No. 752,559

4 Claims.

This invention relates to methods of and means for conditioning, the interiors of refrigerators or other enclosures used for refrigeration purposes.

The general object of the invention is to provide a double walled enclosure equipped with a system'of air conditioning capable of maintaining a high relative humidity therein, approaching the saturation point, at a desirable low dry bulb temperature. 7

Another object of the invention is to provide a system of air conditioning for use with a refrigerated space in which the transmission of sensible heat through walls or the like will be 15 reduced to a minimum, thereby substantially eliminating reheating of air in the space.

Another object of the invention is to provide a system of air conditioning for a refrigerator or the like in which an air current may be routed 20 to .and from the'refrigerated space through an insulating air passage, whereby the relative humidity in the space will be retained at an opti- .mum point, regardless of variations in atmospheric conditions outside the refrigerator. 2 A feature of the invention resides in the provision of an outer enclosure in combination with an inner enclosure spaced from the outer enclosure whereby a current of conditioned air may circulate between said enclosures in a course 30 to and from a conditioning system.

Another feature of the invention resides in the provision of a conditioning system, 'a double walled enclosure,- and a damper arrangement for directing a flow of air between the 35 walls of said enclosure in one direction during certain seasons of the year and for reversing theflow of air during other seasons of the year. Other objects and features for producing and maintaining desired atmospheric conditions in refrigerated spaces at a minimum of expense for conditioning, and providing advantages in control, flexibility of operation to compensate for changes in load, and adaptation to opera .tion under winter and summer conditions, will be apparent from the following description of typical formsof the invention to be read inconnection with the accompanying drawing, in which:

Fig. 1 illustrates, diagrammatically, a-double 50 walled refrigerator to which one form "of. the

invention is applied, and

Fig. 2 similarly illustrates, in sectional diag'rammatic form, a modification and amplifica I tion of the system of Fig. '1. 55 Considering the drawing, similar designations referring to similar parts, numeral 3 designates, diagrammatically, a refrigerator adapted to store meats, for example. While the specification will be directed more particularly to the application of this invention to refrigerators, it may 5 similarly be applied to any enclosure, such as an area in a storage warehouse, where it is desired to maintain a high relative humidity at a suitable low temperature for preserving meats or other products. The refrigerator 3 is provided in the usual manner with access doors, drains, fixtures for supporting carcasses, lights, etc., not shown.

Inner walls or partitions l, floor 5 and ceiling 6, are spaced from the outer walls of refrigerator 3. In efiect, they constitute false sides. floor and ceiling, suitably supported and spaced respectively irom the exterior side walls, floor and'ceiling of refrigerator 3, with the result that an air space or passage completely surrounds the interior enclosure, numbered '1.

First considering summer operation and referring more particularlyto Fig. 2, dampers 8 and 9, of conditioner casing Iii, will be in open position, as illustrated, whereas dampers H and- I! will be closed. Air will be forced over cooling coils ill by fan It, flow through opening I5, damper 9 being open, and enter plenum space I6. Distributing openings ii in the partition separating plenum space Hi from the refrigerated area may be spaced to provide an equal distrlbution over the whole horizontal cross-sectional area of the refrigerated space or the openings may be arranged to discharge the air directly upon the produce. Thus, for example, openings may be grouped so that the air will impinge upon racks or other supporting means whereon the carcasses are hung. The coils l3 are supplied with refrigerant at a desirable low. temperature from a source served by a refrigcrating machine or the like, with the result that the air leaving the coils is cold and substantially saturated. In practice, the relative humidity is between 35-95 per cent in the box. After contacting with the meat or other produce, the air leaves space 1 through discharge openings l8 in the false floor (or the false floor may be omitted in some cases), then proceeds through the surrounding passages l9 and back to the coils through inlet "20, the damper 8 being open. In travelling from space 1 back to the conditioning apparatus, the air serves as an insulating bank which absorbs the sensible heat flowing inwardly, under summer conditions, through the outer walls of the box 3. This sensible heat, therefore, can have no effect in raising the dry bulb temperature within space 1 with the result that the usual lowering of relative humidity due to sensible heat transmission is substantially completely eliminated. This heat coming in through the walls is instead picked up by the movingcurrent of return air and dissipated in its course through the cooling coils.

Under winter operating conditions, dampers 8 and 9 will be closed and dampers II and open, with the result that the cycle, in effect, is reversed. The advantage in reversing the circulation, under winter conditions, is that an excessive relative humidity is avoided. The sensible heat in leakage through the walls of refrigerator 3 is usually very small in the winter time. Consequently,

. the temperature in the refrigerator will often remain at the desired low point riods of time without necessity for active refrigeration service. Under such conditions, coils l3 will during a considerable period of time be operative only for short intervals. Dehumidification will, therefore, take place only during these short periods and is insufficient to keep the relative humidity in space 1 from rising to an undesirable high point. Wet or slimy surfaces on the meat are produced under such conditions. However, by reversing the circulation, such sensible heat as is transmitted inwardly through walls of refrigerator 3 will be picked up first by the circulating air and delivered into space 1. This sensible heat 'will serve to raise thedry bulb temperature of space 1, thereby reducing the relative humidity. Under practical operating conditions, this sensible heat increment isofte'n found adequate for maintaining the percentage of humidity at the prescribed optimum point for the dry bulb temperature obtaining in space 1. Should the relative humidity rise above the desired percentage, a heating element 24 under control of hygrostat 25 will become operative and supply heat to the'air sent through passages 19 to space 1, until suchtime as the relative humidity drops to the desired point. The heater may be an electrical or steam device and the hygrostat will control the circuit or flow of steam, as the case may be, in the usual manner.

In Fig. 1, the operation is substantially the same except that no forced circulation is provided. Cooling coils l3 served by refrigerant from a desired source, cool the air, as in Fig. 2. The air leaving cooling coils l3 has a desirable high relative humidity. After contacting with the carcasses-in space 1, it leaves through discharge ports I. and then rises to space 2|, under summeroperating conditions, clue to its pickup of H sensible heat in'travelling through passages I 9 between the outer walls of refrigerator 3 and the inner false sides 4. This absorption of sensible heat will be suflicient to cause a movement of the air by reason of convection, so that the cycle may continue substantially without interruption.

The air, upon reaching the upper space 2|, spills over side members 22, again to be cooled and dehumidifled. 'Under winter operating conditions, side members 22 are shifted to the positions designated by numeral 23 and element 6 is removed with the result thatthe circulation is reversed. Thus, the same objects as are attained with the system of Fig. 2 may be carried out with- Y out the. use of a fan or other air propelling means.

To accomplish defrosting of coils 13, an outside air inlet 25 and relief outlet 26 may be provided and connect the casing 10 with an area outside for substantial pethe refrigerator. By opening the inlet and relief dampers 21 and 28 and keeping closed the dampers 8, 9, II and 12, a circulation of warmer outside air may be carried on over the coils and the moisture from the coils removed. This avoids sending moisture laden air into space 1, during defrosting periods, when relative humidities would in temperature therein, and may control the operation of a refrigerating machine, or other source of refrigerant, not shown, which functions to supply refrigerant to the coils when the temperature in the area rises above a desired degree and to stop the flow of refrigerant when the temperature drops to the desired low point.

By providing an air space between the inner refrigerated area and the exterior walls, and by circulating air-through said space, the use of fixed insulating material in the construction of the outer walls of the refrigerator is largely obviated. The cushion of air in said space is, in effect,

an insulator under summer operating conditions, preventing transmission of heat through the outer walls from reaching the refrigerated space.

Under winter conditions, too, the cushion of air in the space between the outer and inner walls serves to absorb heat transmitted inwardly through the outer walls. In all seasons of the year, the air in this space, additionally, is an essential element in the control of humidityconditions in the refrigerated space, in a manner impossible of accomplishment by the use of insulated walls alone Since certain changes in carrying out the above process and in the constructions set forth, which embody the invention, may be made without departing from its scope, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. In a refrigerator, dehumidifying apparatus, means including a fan for circulating air in a closed circuit between said apparatus and the storage area of the refrigerator, means for interrupting the circulation of air between said area and said dehumidifying apparatus, means afiording communication between the dehumidifying apparatus only and the atmosphere surrounding the exterior of the refrigerator when said circulation of air is interrupted,'said fan being arranged to circulate air from said exterior atmosphere over said dehumidifying apparatus when said circulation of air between said apparatus and said storage area is interrupted.

2. A refrigerator of the character described having outer walls, a false floor, a false ceiling, false sides, the, area within the false floor and ceiling and sides constituting a space for the storage of produce, the space between said false floor'and ceiling and sides and the outer walls of said refrigerator constituting an air passageway, refrigcrating coils positioned in the upper portion of said refrigerator, and adjustable baflle means in combination with said refrigerating coils, said baflle means being adapted when in one position to route air from the refrigerating coils directly into .the'conditioned space and back to the refrigerating coils through said air passageway, and adapted, when in another position, to route air from the refrigerating coils through said air passageway to said conditioned space and then to said refrigerating coils.

3. ,The method of controlling the relative humidity of a refrigerated space which consists in subjecting air to a conditioning step in which heat is abstracted therefrom, routing the conditioned air successively through said space and then' through a passageway surrounding said space and then reconditioning said air thus circulated prior to recirculation of the air, such operation taking place under predetermined operating conditions tending to cause undesirably low relative humidity within said space, and, under other predetermined operating conditionstending to cause undesirably high relative humidity within said space, routing the conditioned air from the conditioning step successively through said passageway and then through said space,

affected the air in said refrigerated space, whereas under said other predetermined operating conditions the heat infiltration will be utilized to increase the temperature of air in said space and to lower the relative humidity thereof.

4. A refrigerator of the character described having outer walls, afalse ceiling, and false sides, the area contained within said false ceiling and said false sides constituting a space for the storage of produce, the space between said false ceiling and false sides and the outer walls of said refrigerator constituting an air passageway, means providing communication between said air passageway and the lower portion of said storage space, refrigerating coils positioned in the upper portion of said refrigerator, and adjustable bailie means in combination with said refrigerating coils, said baiiie means being adapted when in a predeterminined. position to route air from the refrigerating coils directly into the conditioned space and back to the refrigerating coils through said air passageway and adapted, when in another predetermined position, to route air from the refrigerating coils through said air passageway to said conditioned space and then to said refrigerating coils.

y WALTER JONES.

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