US2761290A

US2761290A - Refrigerator insulation drying arrangement

Info

Publication number: US2761290A
Application number: US379179A
Authority: US
Inventors: Lawrence A Philipp
Original assignee: Nash Kelvinator Corp
Current assignee: American Motors Corp
Priority date: 1953-09-09
Filing date: 1953-09-09
Publication date: 1956-09-04
Anticipated expiration: 1973-09-04

Description

United States Patent REFRIGERATOR INSULATION DRYING ARRANGEMENT Lawrence- A. Philipp, Detroit,

Kelvinator Corporation, of Maryland Mich., assignor to Nash- Detroit, Mich., a corporation This. invention relates to refrigerating apparatus and more particularly to such temperatures are maintained.

ln refrigeratorsof the household type having multiple compartments and evaporators, one of the difficulties 'resides in keeping the cabinet heat insulation dry and therefor effective. is due to condensation occurring within the cabinet walls of water vapor which entrainedin room air, finds its way into the cabinet casing through clearances which are impractical to seal, such as the clearance around the door latch handle, the joints of heat Instead of allowing the moisture vapor to condense and wet the insulation, it has been proposed to take advantage of the principle of diffusion by arranging for flow of moisture vapor by vapor pressure differential from the vicinity of the insulation to the freezing evaporator Where the moisture vapor is deposited as frost on the evaporator for removal at the time of defrosting of the evaporator. However, to keep the insulation dry by diffusion andipan ticularly in refrigerators having freezing and cooling evaporators for separate multiple compartments entails problems of moisture flow especially in such arrangements where the freezing evaporator is exposed toadjacent cabinet insulation. In addition, there exists the problem of controlling or distributing moisture flow to surfaces of the freezing evaporator moisture flow from all points within the cabinet walls to the freezing evaporator.

Accordingly, it is an object of my invention. to provide for a refrigerator of the type having a food storage compartment evaporatorand a freezing compartmentevaporator, an improved arrangement for' directing the flow of moisture vapor by diffusion. from the insulation about the food storage compartment to the freezing evaporator for deposit as frost thereon.

Another object of the invention is to provide an improved arrangement for directing and distributingvapor moving by diffusion to areas of the freezing evaporator to the end of inducing all moisture throughout tlie cabinet walls to flow to the freezing evaporator.

Another object of the invention resides in enclosing the insulation around the freezing evaporator and sealing it so that no moisture can reach the insulation and arranging for flow of moisture from the insulation around the food storage compartment liner to the freezing evaporator.

A further above mentioned character embodying the principle of diffusion to keep the cabinet insulation dry and at the same time provide for drainage of moisture during. defrosting without wetting the insulation.

More specifically, it is an object of my 'invention to' provide upright walls extending between the insulation of the food storage compartment above a freezer drip pan forming passages for passage of moisture lad'e'n. air to the freezer and arranging drip deflectors on 'saidlwalls to divert water, during defrosting, into the drip pan.

As is well known, wetting of the insulation breaker finish strips etc;v

such that there will. be

object is to provide a refrigerator of the apparatus in which multiple-- denser 50 in the Further objects and. advantages of the presentinvention will be apparent from 'the following description, reference being had to the accompanyingdrawings, wherein-a preferredform of the invention is clearly shown.

In the drawings:

- Fig. l is a front view of a refrigerator having parts of the cabinet broken away to show the interior thereof, and embodying features of my invention;-

Fig. 2 is a vertical sectional view of an upper portion of. the refrigerator;

Fig. 3 is an'enlarged fragmentarysectional view of the refrigerator, taken along the line 3-3of Fig. 2;

i Fig. 4 is an enlarged fragmentary sectional view of the refrigerator, taken along the line 4-4 of Fig. 2;

Fig. 5 is a vertical sectional view of a detail of therefrigerator; and

Fig. 6 is a diagrammatical view of system. o-f'the refrigerator.

Referring to the drawings by characters of reference, the refrigerator includes a cabinet, designated in general by the numeral 20, having a food storage compartment 22-and a freezing compartment 24. In the present arrangement, the freezing compartment 24 is located vertically. above the food storage compartment, but maybe located below the food storage compartment, if desired. Access is gained to the

cornpartments

22 and 24 at the cabinet front which may be closed by a suitable door 28. The cabinet 20 includes a sheet metal casing 30 and. a box-like sheet metalliner 32 of which. the latter forms the inner wall surfaces. of the food. storage cornpartment 22-. Heat insulation 34 is provided between the casing side, rear,: and bottom: walls and the corresponding walls of. the liner 32 to'decrease heat leakage into the food storagecompartment 22.

The. freezing compartment 24 is refrigerated to a low desirable freezing temperature by a refrigerant evaporator 36 of a primary refrigerating system, and the food storage. compartment 22 isi cooled to*the desired above freezing temperature by a refrigerant evaporator 3801: a secondary refrigerating system. 'I'he'freezing evaporator 36 is-disposed within the. freezing compartment 24, andthe coolingevaporator 38 preferably inthe form of a coil or. conduit is attached to the outer wall. surface of liner 32 in good heatconducting relation therewith.

As is illustratedin Fig.6, the" primary refrigerating system includes the freezing evaporator 36, a refrigerant motor compressor unit 40, and. a refrigerant condenser 42. The outlet. of the motor-compressor unit ,40 is connected by a conduit 44 to the. inlet of the condenser 42 whichhas. its outlet connectedin communication with the inletof evaporator 36 by a" smalldiameter or'capillary tube. 46. The tube 46 conducts liquidrefrigerant from the condenser 42' and meters the liquid refrigerant so that theproper. amount of refrigerant is supplied to the evaporator tomaintain desired refrigeration. Connecting the capillary tube 46 and theinlet of evaporator 36 is a heat exchanger evaporator coil 48 which is arranged in heat conducting relation with a heat exchanger conform of a container. The secondary system evaporator 38 has an inlet end 52 andian outlet end 54 connected to and in communication withthe heat exchanger condenser 50 wherein heattremoved from the food storage compartment by the secondary system is absorbed. by the refrigerant of theprimary systemiat the heat. exchanger evaporator 48. On the back of the freezing. evaporator 36 is a refrigerant accumulator 56 from which refrigerant vapor is. withdrawn and returned to the motoncompressor unit 40 through a return conduit 58;

The evaporator 36 comprises a container 60' and a refrigerant evaporator or coil 62. The container60 eX- tends across the cabinet substantially the width of the food storage compartment 22 and from front to back of the cabinet to provide a large freezer chest for storage of foodstuffs to be frozen. In the present arrangement, the evaporator coil 62 is wrapped around the container 6%, and extends along the top, bottom, and sides thereof in good heat conducting relation therewith but, other types of low temperature evaporators may be used. Brackets (not shown) may be used to mount the evaporator 36 on the cabinet casing 30. The motor-compressor unit 40 and condenser 42 may be located in the lower part of cabinet 29 in the usual manner.

Heat insulation is provided between the freezing evaporator as and the casing 30 and to avoid wetting of the insulation, I encase the same in moisture impervious enclosures or envelopes 64. This bagged heat insulation is interposed between the corresponding walls of the easing 39 and the freezing evaporator as and between the bottom of the evaporator 36 and the top of the food storage compartment liner 22 such that, except for its front, the evaporator 36 is encased in bagged insulation. The insulation envelopes 64 may be made of resinous plastic material such as polyethyline plastic sheet and be sealed by the application of heat to melt the plastic material at and seal the joints of the envelopes. Preferably, the top and side envelopes 64 of insulation are spaced from the evaporator 36 to provide spaces therebetween for frost to form on the evaporator 36. To this end I provide a spacer 68 comprising a horizontal panel 7% overlying the top of the evaporator 36 having depending sides '72 which overlie corresponding evaporator sides and extend down substantially the bottom of the evaporator 36. Secured to and on the underside of the panel 7% are spacer members 74 preferably of low heat conducting material which rest on the top of the evaporator 36 to space panel 70 therefrom. Carried by and secured to the inner surfaces of the panel sides 72 are spacer members 78 for spacing the side panels 72 from the sides of the evaporator 36. Preferably, the spacer panels are made of a water repellant material, such as waxed, heavy cardboard.

Spaced below the evaporator 36, the lower insulation envelope 64 rests on the top wall of the food storage compartment liner 22, and resting on the insulation is a drip pan fill. The drip pan 30 is a sheet metal pan which extends substantially from front to rear of compartment 24 and extends beyond the sides of evaporator 36 to the sides of the spacer panels 72 to catch all drip from the evaporator and any moisture which may run down the inner surfaces of the spacer panels 72..

In accordance with my invention, I provide for keeping the insulation 34 dehydrated by a particular arrangement of a plurality of passages 82 which connect the space between liner 32 and casing 30 for flow of water vapor by diffusion to the evaporator 36 for deposit as frost thereon. To this end, I provide upright wall members 84 extending upwardly from the sides of liner 32 to the freezing compartment 24 having the vertical passages i-Z which establish communication between the insulation 3:4 and the freezing evaporator 36. Also, the wall members 84 extend substantially from the trimbreaker strips rearwardly substantially the depth of the liner 32 to provide moisture vapor flow throughout the insulation 34 of the cabinet side walls and to provide distribution of the vapor over the entire side areas of the evaporator sides.

To further increase vapor flow passage capacity, I provide along each of the upper side edges of the liner 32, a horizontal passage 38 which runs from front to rear of the liner 32 in communication with the insulation 34 and with passages 82. The passages 88 may be provided economically by welding or otherwise securing storage compartment to the angle members 90 to the top and sides of the liner as illustrated in Fig. 2. In the horizontal legs of the angle members 90 is a plurality of outlet apertures 92 communicating with the insulation receiving space between the top wall of liner 32 and the drip pan 8t and the horizontal passages A plurality of water vapor inlets 94 are provided in the vertical legs of the angle members for flow of water vapor from insulation 34 into the horizontal passages 83. By diffusion, water vapor flows from the high pressure vicinity of the insulation 34 up through passages 82 to the freezing evaporator 36 and other water vapor flows by diffusion from the vicinity of the insulation 34 through inlets 94 into the horizontal passages 83 whence the moisture vapor flows out of outlets 92 and up passages 32 to the evaporator 36. Thus, water vapor which leaks into the cabinet entrained in the room air is deposited as frost onto the freezing evaporator 36 instead of wetting and consequently rendering the insulation 34 ineffective.

The wall members 34 may be economically fabricated of heavy, waxed cardboard and may comprise a corrugated sheet 96 and a backing sheet 95. These sheets may be clipped, stapled or be otherwise secured together to form the passages 82. At its top, each of the wall members 84 is provided with an inwardly directed flange 100 which extends into the space between the lower edge of the spacer panels 72 and the drip pan 80. The tops of the wall members or flanges 1% are inclined downwardly toward the drip pan 80 so as to drain moisture thereinto.

Secured to the rear wall of the food storage compartment liner 32 is a pair of vertical channels 102 which form passages 104 for the passage of moisture vapor from the rear wall insulation to the evaporator 36. The channels 1'62 extend upwardly from points adjacent the bottom of the liner 32 to the space between the bottom of the freezing evaporator 36 and the drip pan fill. The secondary system evaporator 33 on the rear wall of the liner 3?; spaces the channels from the liner wall so that vapor throughout the insulation space of the rear wall can flow laterally into the channels 102. The drip pan 80 may be provided with a suitable drain (not shown).

From the foregoing description, it will now be understood that I have provided a new and improved arrangement to effect vapor diffusion and passage of water vapor from the spaces occupied by the insulation of the food freezing evaporator whereon the moisture deposits and is frozen to the end of keeping the insulation dry and therefore effective. Furthermore, it will be noted that I have effected flow of water vapor from between the side walls of the liner and casing by the provision of passage forming means which is so constructed as to increase flow to the freezing evaporator. Also, I have provided a new and improved arrangement of passage forming means for conducting water vapor to the freezing evaporator including a large flow capacity distributed over an area such that all insulation is dehydrated. In addition, I have provided wall means which form passages for conducting water vapor to the freezing evaporator and also function to deflect water drip into a drip pan beneath the freezing evaporator.

Although only a preferred form of the invention has been illustrated, and that form described in detail, it will be apparent to those skilled in the art that various modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

1. Refrigerating apparatus comprising, a cabinet casing having side walls, a liner within said casing forming a food storage compartment and having side walls spaced from the casing side walls, a refrigerant cooling evaporator cooling said compartment, a refrigerant freezing evaporator within said casing externally of said liner, heat insulation between said freezing evaporator and said casing and between said freezing evaporator and said liner, second heat insulation between said liner and easing side walls, opposite side wall means spacing said first insulation from the sides of said freezing evaporator, a drip and air baffle plate beneath said freezing evaporator between said freezing evaporator and the first insulation between the freezing evaporator and said liner, said baflie plate being spaced from the lower edges of said opposite side wall means, upright wall means forming air flow passages establishing communication between the space between said liner and casing and said freezing evaporator for diffusion of vapor, and means on said wall means to direct defrost Water onto said baflle extending laterally between the lower edges of said wall means and said plate.

2. Refrigerating apparatus comprising, a cabinet casing, a box-like liner within said casing forming a food storage compartment, a cooling element within said casing externally of and cooling said liner, a second liner within said casing spaced from said first liner and forming a freezing compartment, a cooling element refrigerating said second liner and disposed between said second liner and said casing, heat insulation in the space between said liners, moisture impervious material enclosing said insulation, heat insulation in the space between said second liner and said casing, a drip pan supported on said moisture impervious material below said second evaporator, moisture impervious material enclosing said second insulation, insulation in the space between said first liner and said casing, wall means npported by said last-named insulation against one edge of said first insulation having a plurality of upright ducts establishing communication between said last-named insulation and said secondnamed insulation, said plurality of ducts having outlets open to the space between said drip pan and said second cooling element for passage of water vapor from said lastnamed insulation to said second-named insulation to said second named cooling element, and angle members cooperating with corners of said box-like liner forming passages in communication with said last-named insulation and with said ducts to conduct water vapor to said second cooling element.

References Cited in the file of this patent UNITED STATES PATENTS 20 2,515,892 Philipp July 18, 1950 2,576,665 Bixler Nov. 27, 1951 2,672,030 Schweller Mar. 16, 1954