US2180974A - Refrigerating machine - Google Patents

Description

Nov. 21, 1939. L w, ATCHISQN ET AL. 2,180,974

REFRIGERATING MACHINE Filed Dec l 1937 2 Sh ee ts-Sheet 1 James L Fietch'er, b Wwf 7 j y Their/Attorney.

Nov. ZE, E939 L. w. ATcHlsoN Er AL REFRIGERATING MACHINE Filed Dec. l, 1.937 2 Sheets-Sheet 2 Inventors: Le on euncl.A VV. Atchison,

Patented Nov. 21, 1939 REFRIGERATING MACHINE Leonard W. Atchison and James `L. Fletcher,

Schenectady, N. Y., assignors to General Electric Company, a corporation of New York Application December 1, 1937, Serial No. 177,520

12 Claims.

Our inventionrelates to refrigerating machines, and particularly to refrigerating 'machines having cabinets within which the circulation of air is utilized to maintain a plurality of 5 temperature zones..

'I'he cabinets of refrigerating machines are sometimes provided with an` air circulating means such as a fan for producing a circulation of air through the cabinet and over the evaporator or cooling element. When the evaporator is utilized also to provide a freezing zone, substantial quantities of moisture are abstracted from the circulated air and this causes a layer of frost to be formed on the surface of the evaporator. Any

foodstuffs placed within the cabinet are thereby dehydrated undesirably. Accordingly, it is an object of our invention to provide a refrigerating machine having a cabinet in which are maintained a pluralityof temperature zones and including an improved arrangement for preventing the dehydration of foods placed in one of the compartments and for obtaining effective control of the temperature in that compartment. y

Another object of our invention is to provide a refrigerating machine including a cabinet having a plurality of temperature zones and an improved arrangement for utilizing the evaporator of the refrigerating machine to provide a freezing zone and to maintain a relatively high range of temperatures in the food compartment.

Further objects and advantages of our invention will become apparent as the following description proceeds, and the features of novelty which characterize our invention will be pointed out with particular-ity in the claims annexed to and forming a part of this specification.

For a better understanding of our invention, reference may be had to the accompanying drawings, in which Fig..1 is a front elevation view partly in section of a household refrigerating machine emembodying-our invention; Fig. 2 is a sectional side elevationview on the line 2-2 of Fig. l, and Fig. 3 is`a sectional plan View on the line 3-3ofFig.1.

Referring now to the drawings, we have shown a householdrefrigera'ting machine comprising a cabinet I0 having an outer wall and an inner wall I2 spaced apart and provided with a body of heat insulation I3 therebetween. Within the cabinet and spaced from the wall I2, we provide a liner I4 of metal or other suitable thermally conductive material forming a food compartment. As clearly shown in Fig. 3, the liner Mseals the f food compartment from the remainder of the in- (Cl. (i2-102) terlor of the cabinet, a door I5 being provided to close the food compartment and a door I6 being .provided at the left of the door I5 to close the other portion of the interior of the cabinet. In

order to cool 4the cabinet, we provide a refrigerant 5 evaporator I 1 arranged in the lower portion'of the cabinet at one side of the liner I4 and we house the evaporator or cooling element |'I in a sheet metal casing I8. In order vto supply refrigerant or coling medium to the evaporator I'I, We pro- 10 vide a condensing unit arranged in a compartment below the thermally insulated food compartment. The condensing unit comprises a sealed casing 9 Within which are arranged a motor and a refrigerant compressor', a refrigerant 15 condenser 20 at one side of the casing I9, and a oat valve chamber or refrigerant receiver 2|. Refrigerant is compressed by the compressor within the casing I9 and is discharged through a connection 22 to the condenser 20 where vit is cooled by the circulation of air produced by operationfofiaifanf(not shown) arranged rin a shroud '23 and driven byy a motor 24. The re.- frigerant is'liquefled within theconden'ser and ows through a'connection 25 to the float valveA 25 chamber 2|. When a predetermined amount of liquid refrigerant has collected in the chamber 2|, a float therein rises and the refrigerant ows through a liquid line v2li to the evaporator The liquid refrigerant within the evapora- 30 tor absorbs heat from articles placed within the evaporator and from the air circulating thereover, and is vaporized, the vaporized refrigerant collecting in a header 21 and being withdrawn therefrom through a suction line 28 35 and returned to the compressor within the casing I9. The evaporator Il is arranged to provide a plurality of freezing chambers Within which Water, desserts or the like .may be frozen. The evaporator comprises twoV refrigerant cir. 40 culating sections, an upper section having' refrigerant circulating conduits 29 depending from and communicating with the header 2l, and the lower section havinga plurality of conduits 30 communicating with and depending from a header 3|. Refrigerant is admitted to the conk'duits 29 and 3 0 throughbranches ofthe liquid line 26. The refrigerant vaporizedin the lower ,l

evaporator .rises through an Vequalizer connecltion 32 to the header 21. An evaporator similar to that illustrated is described and claimed in Patent No. 2,110,002,- granted March 1, 1938,`to Chester Lichtenberg,y land. assigned to the same assignee as the present application. We do not,

l-oi? the food compartment.

therefore, herein claim anything shown or disclosed in the said Lichtenberg application.

, In order to circulate air through the interior of the refrigerator cabinet and over the ex` terior walls of the liner I4 and thereby cool the food storage compartment without undesirably reducing the relative humidity therein, we provide a fan 33 driven by a motor 34 mounted Within an opening 35 in the rear wall of the casing I8 which is spaced from the rear wall of the cabinet. The fan 33 is operated to circulate air from the evaporator or freezing compartment around the walls of the liner I4 as indicated by the arrows and over the top of the liner I4 to a compartment or chamber 36 above the evaporator compartment and at oneA side The circulating air returns to the evaporator compartment through an opening 31 between the top edge of the casing I8 and the door I6, and' also through an opening 38 in the top of the casing I8 at the rear of the evaporator I1. 'I'he two inlets 31 and 38 to the freezing compartment divide the air circulating therethrough into. two streams. 'Ihe air entering through the opening 38 passing directly to the fan 33 while the air entering through the opening 31 passes around the walls of the evaporator I1 and is, therefore, cooled before being discharged from the compartment by operation of the fan. The evaporator I1 is, therefore, arranged in the path of only one of the streams of air and the air circulated by the fan 33 is a mixture of air which has been cooled by the evaporator and air recirculated without cooling. We provide doors 39 and 40 on the upper and lower portions of the evaporator to prevent the passage of air through the freezing chambers of the evaporator. The circulated airis, therefore, cooled by passage over the outerlwalls of the evaporator and substantially no circulation of air is produced within the freezing chambers. The proportion of air in the two streams passing through the evaporator member may be varied by adjusting a damper 4I arranged in a sleeve 38a about the opening 38 to change the effective size of the opening 38.

The temperature of the evaporator I1 is maintained within predetermined desired ,limits by controlling the operation of the compressor, acontrol device 42` having a thermostatic element 43 in contact with the side of the evaporator I1 being utilized for this purpose. .The temperature of the evaporator I1 may, therefore, be maintained below freezing, so that water, desserts and other foods may be frozen within the freezing chamber. It is desirable to maintain the temperature of the air within the food compartmentwithin a range of from F to 50 F. We, therefore, provide a control device 44 having a thermostatic element 45 arranged within the food compartment in the upper portion thereof, to control the operation of the fan 33, so that air is circulated over the outside of the liner I4 only when it is desired to cool the air within the food compartment. The air within the food compartment is circulated by natural convection, the warmer air rising to the upper portion. For this reason, the control element 45 is placed in the upper portion of the food compartment where it is responsive to the lhighest temperature-therein. Suitable supports, such as grille-like shelves 48, are provided .for articles to be cooled within the compartment. The fan 33 is normally operated at substantially constant speed and the rate of cooling of the food compartment will, therefore, vary with the temperature of the evapora- -tor I1. When the evaporator I1 is being utilized to freeze articles placed therein, the temperature thereon may be adjusted to remainvery low for a considerable period of time. The air circulated by the fan 33 will, therefore, be cooled to a greater extent and will effect a desired cooling of the liner I4 in a shorter time. In extreme cases, the motor 34 may be required to start and stop the fan 33 at comparatively short intervals. The air admitted through the opening 38 tends to prevent this short-cycling of the fanmotor and also prevents freezing of food in the compartment 36. The opening 38 may be selected of such size that at the lowest possible temperatures of the evaporator I1, there will be suflicient air admitted through the opening to prevent shortcycling of the fan motor.- The damper 4I is provided so that when the evaporator I1 is operating at higher temperatures, the amount of air drawn through the opening 38 may be reduced to cause the fan 33 to draw a greater portion of the circulatedfair over the evaporator I1 where it is cooled. It is, therefore, apparent that the damper 4I may be adjusted to provide satisfactory operating periods of the fan motor 34. The control of the damper may be made automatic by providing a temperature responsive element 4Ia in the stream. of air leaving the fan, the element 4Ia being connected to close the damper on a rise of the temperature of the air discharged by the fan.

The evaporator compartment contains the coldest air, and the air discharged from this compartment circulates over the liner I4 and thence through the compartment 36. The circulating air, however, does not reduce the temperature of the food compartment vwithin the liner I4 to its own temperature, and the food compartment is, therefore, maintained at a temperature intermediate that of the compartment 36 and the freezing compartment. The compartment 36 provides a convenient place for the storage of bottled goods and the like at temperatures which lie within a range of say, 36 F. to 44 F.

Ventilation of the food compartment is sometimes desirable to remove stale air and decrease the tendency of foods to become odoriferous. We, therefore, provide an opening 41 in the sealing gasket 48 at the top of the door I5 and also a drain opening 49 at the bottom of the casing I4 which provides 'ia drain for any moisture collecting in the casing and also provides a discharge opening for vitiated aix'. It will be evident that the air collected within the casing I4 will tend to pass through the drain 49 due to the effect of gravity and some Ventilating air will, therefore, be drawn through the opening 41 into the food compartment.

Any moisturecollecting inthe main portion of the cabinet and in the evaporator chamber may be drained out through a drain connection 50. The drains 49 and 50 convey the drain water to a pan 5I mounted on a bracket 52 in the condensing unit compartment below the cabinet.

During the operation of the refrigerating machine illustrated, the air in the cabinet will be circulated whenever the temperature of the upper portion of the food compartment rises to a value suicient to operate the control 44 and ,startthe fan motor 34. Fan 33 will then operate to draw air through the cooling compartment in the two streams from the openings 31 and 38 and to cool the air in the stream passing over the evaporator I1. The operation of the fan 33 will maintain a continuous circulation of air through the freezing compartment around the exterior of the liner I4 and through the compartment 36 as long as lthere is a demand for cooling of the food compartment. If articles are placed Within the freezing chambers on the ably lower and the air recirculate more of the -mally shelves cooled by the conduits 29 and 30, the temperature of the evaporator II may be adjusted by operation of 'the control 42 to a low value for quick or sharp freezing. At such times, the temperature of the evaporator I'I will be considercirculated thereover by the fan 33 will be cooled to a greater extent, If such condition of operation is prolonged, the element Ma, may move the damper 4I to increase the eiective size of the opening 38 in order to va'ir without cooling. The mixture of air yformed by the intermingling of the streams before their passage over the liner i4 will be at a higher temperature than before movement of the damper and will, therefore, require a correspondingly longer time to reduce the temperature of the air within the food compartment thereby increasing the running time of the fan and preventing short-cycling and freezing of food in the compartment 36. Throughout the operation of the refrigerating machine, a small quantity of Ventilating air will be drawn into the food compartment and will circulate therethrough, al corresponding quantity of cold stale air leaving the compartment through the drain opening 49.-

While we have disclosed one embodiment of our invention in connectionwith a household refrigerating machine, other modifications will readily be apparent to those skilled in the art. We do not, therefore, desire our invention to be limited to the particular construction shown and described, and-we intend' in the appended claims to cover all modifications 'within the spirit and scope of our invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. A refrigerating machine including a therinsulated cabinet, means including a liner for providing a food storage compartment within said cabinet, means for circulating air through the interior of vsaid cabinet and over the exterior. of said liner, means for dividing into two streams the air circulating through said cabinet, means for reuniting said streams prior to the circulationof said air over said liner, and means including a cooling element arranged to cool the air in only one of said streams for cooling said food compartment. 2. A refrigerating machine including a thermally insulated cabinet, means including a liner for providing a food storage compartment within said cabinet andfor preventing the passage of air from the interior of said cabinet to said food compartment, means for circulating air through the interior of said cabinet and over the exterior of said liner, means for dividing into two streams .the air circulating through said cabinet, means for reuniting said streams prior to the circulation of said air over said liner, and means including a cooling element arranged to cool the air in only one of said streams for cooling said food compartment.

3. A refrigerating machine including .a thermally insulated cabinet, means including a liner for providing a food storage compartment within said cabinet and for preventing the passage of air from the interior of saidcabinet to said food compartment, means for circulating air through the interior of said cabinet and over the exterior o1' said liner, means for dividing into two streams the air circulating through said cabinet, means for reuniting said streams prior to the circulation of said air over said liner, means including a cooling element arranged to cool the air in only one of said streams for cooling said food compartment, and means responsive to the temperature of said reunited streams prior to circulation over said liner for varying the relative volumes of air in said two streams.- l

4. A refrigerating machine including a thermally insulated cabinet, means including a/liner for providing a fo'od storage compartment within said cabinet and for preventing the passage of air from the interior of said cabinet to said food compartment, means for circulating air through the interior of said cabinet and over the exterior of said liner, means for dividing into two streams the air circulating through said cabinet, means for reuniting said streams prior to the circula- .tion of said air over said liner, means including a cooling element arranged to cool the air in only one of said streams for cooling said food compartment, and means responsive to the temperature of the air within said food compartment for ,said liner to cool said food compartment, means cooperating with said last mentioned means for. providing two streams of air circulating through said cooling chamber, and means including a cooling element arranged in the path of only one of said streams for cooling said circulated air.

6. A refrigerating machine including al thermally insulated cabinet, means includinga' liner for providing a food storage compartment within said cabinet and for preventing the passage of air fromthe interior of said cabinet to said food compartment, means for circulating air through the interior of said cabinet and over the exterior of said liner, means for dividing into two streams the air circulating through said cabinet, means for reuniting said streams prior to the circulation of said air over said liner,`means including a cooling element arranged to cool the air in only one of said streams for cooling said food compartment, means responsive to the temperature of the air within said food compartment for controlling the operation of. said air circulating means, and means arranged to vary the vpropor-Y tion of air flowing in each of said streams for varying the temperature of said circulating air.

7. A refrigerating machine including a thermally insulated cabinet, means for dividing the interior of said cabinet into a food storage compartment and a freezing compartment land an intermediate temperature compartment, said:`

ment arranged in the path of only one of said streams of air for providing a freezing zone in said freezing compartmentI and for cooling the air circulating through said cabinet.

8. A refrigerating machine including a thermally insulated cabinet, means for dividing the interior of said cabinet into a food storage compartment and a freezing compartment and an intermediate temperature compartment, said freezing compartment being arranged below said intermediate temperature compartment, said means including a liner enclosing said food comcompartment and preventing the passage ofair between said food compartment and said other compartments, means for circulating air through the interior-of said cabinet from said intermediate compartment through said freezing compartment and thence over the exterior surface of said liner, means including two openings providing communication between said freezing compartment and said intermediate temperature compartment for dividing into two streams the air circulating through said freezing compartment, and means including a cooling element arranged in the path of only one of said streams of air for providing a freezing zone in said freezing compartment and for cooling the air circulating through said cabinet. v

9. A refrigerating machine including a thermally insulated cabinet, means for dividing the interior of said cabinet into a food storage compartment and a freezing compartment and an intermediate temperature compartment, said means including a liner enclosing said food compartment and preventing the passage of air between said food compartment and said other compartments, means for circulating air through the interior of saidv cabinet from said intermediate compartment through said freezing compartment and thence over the exterior surface of said liner, means for dividing linto two streams the air circulating through said freezing compartment, means including a cooling element arranged in the path of only one of said streams of lair for providing a freezing zone in said freezing compartment and for cooling the air circulating through said cabinet, and means for substantiaily preventing the circulation of air through said freezing zone in saidfreezing compartment.

' 10. A refrigerating machine including a thermally insulated cabinet, means including a liner for providing a food storage compartment within said cabinet, means including a fan for circulating air through the interior of said cabinet.

and over ther exterior of said liner, means for dividing into two streams the air circulating through said cabinet, means for reuniting said streams prior to the circulation of said air over 'said liner, means including a cooling element arranged to cool the air in only one of said streams for cooling said food compartment, means for supplying cooling medium to said cooling element, means dependent upon the temperature of said cooling element for controlling said cooling medium supplying means, and means dependent upon the temperatureof the air within said food compartment for controlling the operation of said fan.

11. A refrigerating machine including a thermally insulated cabinet, means including a liner for providing a food storage compartment within said cabinet, means including a fan for circulating air through the interior of said cabinet and over the exterior of said liner, means for dividing into two streams the air circulating through said cabinet, means for reuniting said streams prior to the circulation of said air over said liner, means for changing the relative volumes of air circulated in said two streams, means including a cooling element arranged to cool the air in only one of said streams for cooling said food compartment, means for supplying cooling 'medium to said cooling element, means dependent upon the temperature of said cooling element for controlling said cooling medium supplying means, and means dependent upon the temperature of the air within said,food compartment for controlling the operation of said fan. l

12. A refrigerating machine including a thermally insulated cabinet, means for dividing the lstreams the air circulating throughv said freezing compartment, and means including a `cooling element arranged in the path of only one of said 'streams of air for providing a freezingzone in ,said freezing compartment and for cooling theV air circulating through said cabinet.; c

LEONARD W. A'cHIsoN. JAMES L. FLETCHER.

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