US2317082A - Refrigerating apparatus - Google Patents

Description

pil 20, 1943.

Ln A.l=HlLlPF Filed Dec. 6,1940

2 Sheets-Sheet l April 20, 1943. L. A. PHILIPP 2,317,082

REFRIGERATING APPARATUS Filed Deo. 6, 1940 2 Sheets-Sheet 2 A T TO I 1N E Y Patented Apr. 20, 1943 REFRIGERATING APPARATUS Lawrence A. Philipp, Detroit. Mich., asslgnor to Nash-Kelvinator Corporation, Detroit, Mich.,r a corporation oi Maryland Application December 6, 1940, Serial No. 368,845

1 Claim. (Cl. 62-116) This invention-relates to refrigerating apparatus, and, more particularly, to refrigerating a primary refrigerating system having one or more cooling elements thermally associated with the freezing compartment and having at least one arranged in direct contact with the metallic inner lining of that compartment, and a secondary refrigerating system having a cooling element arranged in direct contact with substantially all of the outside surface of the metallic inner lining .of the food compartment, and also having a condensing element arranged in heat conducting relation with that cooling element of the primary system which is in direct contact with the inner lining of the freezing cimpart-V ment. l

It is also an object of the present invention to provide an improved refrigerating apparatus which includes an insulated cabinet Whose interior is divided into two compartments separated by an insulating Wall, each of which compartments is provided with a metallic inner lining, a primary refrigerant evaporator thermally l associated with one of the compartments for.

maintaining sub-freezing temperatures throughout said compartment, a secondary refrigerant evaporator arranged in direct contact with substantially all of the outside surface of the inner lining of the other compartment for cooling circulating air therein, and a secondary condenser connected to said secondary evaporator and arranged in direct contact with the metallic lining of the first mentioned compartment.

vAnother object of my invention is to provide an improved arrangement for the ready removability of the aforesaid primary refrigeratingA system as a unitary structure without disturbing the secondary system.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:

. Fig. 1 is a front vertical view partly in elevation and partly in cross-section of a-refrigeratv itng apparatus embodying features of my invenion;

Fig. 2 is a side vertical view partly in elevation and partly in cross-section o1' the apparatus shown in Fig. 1;

Fig. 3 is a side vertical `view in elevation of a portion of the apparatus shown in Fig. 1;

Fig. 4 is a. front vertical view partly in elevation and partly in cross-section of a modified form of refrigeratlng apparatus embodying features of my invention;

Fig. 5 is a side vertical view partly in elevation and partly in cross-section of the apparatus shown in Fig. 4;

Fig. 6 is a side vertical view in elevation of a portion of the apparatus shown in Fig. 4; and

Fig. 7 is a fragmentary view in cross-section of a modified form of refrigerating apparatus embodying features of my invention.

Referring to the drawings, the numeral 20 designates, in general, a. cabinet having a compartment 22 for the storage of foods to be refrigerated, a freezing compartment 23 and a machine compartment 24. The cabinet is provded with insulated walls for enclosing the food storage and freezing compartments, including side walls 26, rear wall 21, bottom wall 29 and top I wall 30. The food storage compartment and the freezing compartment are separated by a fixed, substantially horizontally disposed insulated wall 32. An inner metallic lining member 35 forms the inner walls of the freezing compartment While an inner metallic lining member 36 forms the innerwalls of the food storage compartment. Both of these lining members are preferably provided with a coating of vitreous enamel, such -as porcelain, to provide neat appearing compartments and ones which may easily be cleaned. 'I'he freezing compartment 23 is provided with an opening at the front of the cabinet which is closed by a door 38 while the food storage compartment is similarly provided with an opening at the front of the cabinet which is closed by a door 40. The machine compartment 24 is also provided at the front of the cabinet with an opening adapted to be closed by a movable door 4I. The inner side of this door is 'provided with a bin 42 for storing vegetables and the like. The entire cabinet is raised above the level of the floor by legs 43 to allow air from the room to circulate freely through an opening 44 in the bottom of the machine compartment into said compartment.

Numeral 45 designates, in general, a primary refrigerating system which includes a refrigerant cooling or evaporating element 46 disposed in the freezing compartment 23 and a refrigerant condensing or circulating element 41 disposed in the machine compartment 24. These elements are operatively associated with one another by a liquid supply conduit 46 and a vapor return conduit 50. The entire primary refrigerating system is adapted to be removed as a unit whenever desired as will be later described.

The evaporating element 46 comprises, in general, a serpentine conduit arranged in a single plane and removably secured to the inner lining member 35 at the bottom of freezing compartment 23 by means of a sheet metal plate 52. Supply conduit 49 is connected to one end of the conduit 46 while the other end of the conduit 46 is connected to an accumulator 55 which in turn opens into the return line 50. The cooling element is adapted to provide a surface upon' which a receptacle 54 may be placed for quick freezing of its contents and also is adapted to maintain sub-freezing temperatures throughout Vthe compartment.

The refrigerant condensing element 4'1 compriseain general, a motor compressor unit 56 and a; condenser 5 6. The motor compressor unit is of `the type which Vincludes a compressor and ii'iotor directly connected and enclosed within a hermetically'sealed casing. Units of this type are well known in the art and'further illustration thereof in the drawings is deemed unnecessary. The cooling' of the condensing element may be accomplished either by forced or natural convection. the latter being the one illustrated. Air from the room circulates through the opening 44 and'thence over the condensing unit. A iiue (not shown) may be provided on the rear wall of the cabinet for enhancing the natural convection effect as is well understood in the art.

In operation, the compressor withdraws evaporated refrigerant from Athe evaporating element through the vapor conduit 50, compresses the gaseous refrigerant and delivers it to the condensery 58 wherein it is liquefied and from which it is delivered in liquid form to the evaporator 46 through the supply conduit 48, which, preferably, consists of a length of capillary tubing serving also as a restrictor. This tubing is of proper dimensions to meter the quantity of liquid vrefrigerant flowing from the condensing element to the evaporat'ing element'during entire operation of the system. It is preferably secured to the vapor. return cdnduif .in intimate heat exchange relation therewith.'v

Preferably, the condensing .element is intermittently operated. In order to control the operation of the condensing element, there is provided a thermostatically controlled switch 60 to which is connected a thermostat fluid containing bulb 6I which is disposed in direct contact with the inner lining member -36 of the food storage compartment which is cooled in a manner described below. The switch 6l) ,is adapted to open and close the circuit to thel motor of unit 56 in response to predetermined changes in temperaturewithin the'food storage compartment. Preferably, the thermostat is set so that the evaporating element 46 will be operated at temperatures which cause rapid freezing and so that the food storage compartment will be maintained at temperatures which are lslightly above that which would be likely to cause the` formation of frost in the food compartment. i

Numeral 62 designates, 'in general, a secondary refrigerating system which is adapted to maintain the food compartment 22 at a relatively high and uniform refrigerating temperature and vat a relatively high humidityl so that little dehydration of the food stored therein is accomplished. This system includes a cooling or evaporating element designated in general bythe number 63 and a condensing element designated in general by the number 64. These are operatively connected by a liquid supply conduit 66 and a vapor return conduit 61. The evaporating element 62 consists of a sinuous conduit which is secured in any suitable fashion as by soldering or by some cementing material such as Hydrolene in intimate heat conducting relationship to the outside of the inner lining member 66 of the food compartment. This conduit runs back and forth across the bottom of the liner, then progressively upwardly, embracing three sides of the liner as shown in Fig. 3 until it reaches the top of the lining member where it joins with the vapor return conduit 61. 'I'he condensing element 64 comprises a serpentine conduit arranged in a horizontal plane. 'I'his conduit is disposed in the insulated wall 62 and is secured in intimate heat exchange relation by any suitable means to lining member 66 immediately below the primary evaporator 46 in order to condense the refrigerant evaporated in the secondary system. 'I'he temperature of the refrigerant in the secondary system is determined by the effectiveness of the heat transfer from the secondary condenser to the primary evaporator. The extent or effectiveness of the heat transfer therebetween can be regulated by varying the area of surface of the condenser contacting the inner lining member to produce the desired temperature within the food compartment. The temperature differential between the twoV compartments may of course be varied in other ways as by introducing inert gas into the secondary system.

In operation, the refrigerant evaporated within the secondary system by the heat from the food compartment is conveyed by the return conduit 61 to the condenser 64-where it is condensed and delivered by gravity in liquid form through conduit 66 to the conduit at the bottom of the lining member 36. VIt then circulates upwardly through the sinuous conduit wrapped around the side walls of the lining member up to the top thereof. In this manner the entire food compartment is cooled to a substantially uniform refrigerating temperature'. throughout since no part of the compartment is unexposed to the heat absorbing effect of the secondary evaporator.

' The primary refrigerating system is adapted to be removed as a unit from the cabinet without disturbing the secondary system. The primary refrigerant evaporator is removably secured to the lining member 35 of the freezing compartment by the plate 52 which is fastened to the lining member in any suitable releasable fashion as by screws, bolts or the like (not shown). The condensing unit is adapted to slide out the back of the machine compartment. A removable insulated plug 16 is provided in the rear wall of the freezing compartment. The vapor return and liquid supply conduits extend through the plug T6 into the freezing compartment to connect with the evaporator. The entire primary system may accordingly be removed as a unitary assembly from the cabinet for the purposes of repair, etc.,`

enclosing the food storage and freezing compartments, including side walls 86, rear wall 81, bottcm wall 89 and top wall 90. The food storage compartment and the freezing compartment are separated by a fixed, substantially horizontally disposed, insulated wall 92. An inner metallic lining member 95 forms the inner walls of the freezing compartment while an inner metallic lining member 96 forms the inner walls of the food storage compartment. Both of these lining members are preferably provided with a coating of vitreous enamel, such as porcelain to provide neatl appearing compartments and ones which may easily be cleaned. The freezing compartment 83 is provided with an openeing at the front of the cabinet which is closed by a door 98 while the food storage compartment is similarly provided with an opening at the front of the cabinet which is closed by a door |00. The machine compartment 84 is also provided at the front of the cabinet with an opening adapted to be closed by a movable door The inner side of this door is provided with a bin |02 for storing of vegetables. The entire cabinet is raised above the level of the floor by means of legs |03 to permit air from the room to circulate freely through an opening |04 in the bottom of the machine compartment into said compartment.

Numeral |05 designates, in general, a primary refrigerating system which includes a refrigerant cooling or evaporating element |05 disposed in the freezing compartment 83 and a refrigerant condensing or circulating element |01 disposed in the machine compartment 24. These elements are operatively associated with one another by a liquid supply conduit |09 and a vapor return conduit ||0. The entire primary refrigerating system is adapted to be removed as a unit. whenever desired as'will later be described.

The evaporating element |06 comprises, in general, a sinuous conduit arranged in two horizontal planar sections and ||2, connected in series. Section is removably secured to the top of the inner member 95 by means of a sheet metal plate ||3 while section ||2 is removably secured to the bottom of the inner lining member 95 by means of a sheet metal plate H4. Supply conduit |09 is connected to one end of evaporator section which is in'communication with evaporator section |I2 through a conduit H5. Section ||2 communicates with an accumulator ||6 which opens into the vapor return line |0. The lower evaporator section is adapted to provide a surface upon which a receptacle ||1 may be placed for quick freezing of its contents. The two evaporator sections combine to maintain a uniform sub-freezing temperature throughout tle entire compartment 83.

The refrigerant condensing element |01 comprises, in general, a motor and compressor unit |20, and a condenser |2|. The cooling of the condensing unit may be accomplished either by forced or natural convection the latter being the one illustrated. Air from the room circulates in the well-known manner through the opening |04 over the condenser and out the rear of the cabinet. A flue (not shown) is preferably provided at the rear of the cabinet to enhance the natural convection effect.

In operation, the compressor withdraws gaseous refrigerant from the evaporator |06 through the vapor return conduit I0, compresses the gaseous refrigerant and delivers it to the condenser |2| wherein it is liquefied and from which it is delivered in liqued form to the evaporator |06 through the liquid supply conduit |09. The flow of liquid refrigerant to the evaporator is controlled, preferably, by the supply conduit itself which comprises a capillary tube of proper dimensions to meter the quantity of liquid refrigerant flowing from the condensing element to the evaporating element during entire operation of the system. rIhis capillary conduit is preferably secured to the return vapor conduit ||0 in intimate heat exchange relation therewith.

Preferably, the condensing element is intermittently operated. In order to control the operation of the condensing element, I have provided a thermostatically controlled switch |24 to which is connected a thermostat fluid containing bulb |26 which is disposed in direct contact with the inner lining member 9S of the food storage compartment. The switch |24 is adapted to open and close the circuit to the motor of unit |20 in response to predetermined changes in temperature within the food storage compartment. Preferably, the thermostat is set so that the evaporating element I2 will be operated at temperatures which cause rapid freezing and the food storage compartment will be maintained at temperatures which are slightly above that which would be likely to cause the formation of frost in the food compartment.

Numeral |30 designates, in general, a secondary refrigeratng system which is adapted to maintain the food compartment 82 at a relatively high and uniform refrigerating temperature and at a relatively high humidity so that little dehydration of the foods stored therein is produced. This system includes a cooling or evaporating element designated, in general, by the number |32 and a condensing element designated, in general, by the number |34. These are operatively connected by a liquid supply conduit |36 and a vapor return conduit |31. The evaporating element |32 comprises a sinuous conduit which is secured in intimate heat conducting relationship in any suitable fashion as by soldering or by some cementing material such as Hydrolene to the outside of the inner lining member 9B of the food compartment. This conduit runs back and forth across the bottom of the liner, then progressively upwardly, embracing three sides of the lining member as shown in Fig. 6 until it reaches the top of the lining member where it joins with the vapor return conduit |31. The condensing element |34 comprises a serpentine conduit arranged in a horizontal plane. This conduit is disposed in the insulated top wall and is secured in intimate heat exchange relation by any suitable means such as solder or Hydrolene to lining member immediately above the evaporator section whereby the refrigerant evaporated in the secondary sysltern is condensed. 'I'he temperature of the refrigerant in the secondary system is determined by the effectiveness of the transfer of heat from the secondary condenser to the primary evaporator. The extent or effectiveness of the heat transfer therebetween can be regulated by varying the area of the condenser contacting the inner lining member to produce the desired temperature within the food compartment. The temperature differential between the two compartments may of course be varied in other ways as by introducing inert gas into the secondary system. If desired, the secondary condenser |34 may be disposed in heat exchange relation with the evaporator section ||2 instead of section |I|.

In operation, the refrigerant evaporated within the secondary by the heat from the food compartment is conveyed by the return conduit |81 to the condenser |34 where it is condensed and delivered by gravity in liquid form through conduit |86 to the conduit at the bottom of the lining member 86. 1t then circulates upwardly through the conduit wrapped around the side walls of the lining member up to the top thereof. In this manner the entire food compartment is cooled to a substantially uniform refrigerating temperature throughout since no part of the compartment is unexposed to the heat absorbing effect of the secondary evaporator. A sterilamp |45 may be provided within the food compartment to aid in the preservation of the foods.

'I'he entire primary refrigerating system may be removed from the cabinet as a unitary structure. The structure includes the condensing element |81, evaporating element |86 and a removable insulated closure member |48 which is adapted to close an elongated opening at the rear of the freezing compartment 88. Preferably, the platesy H3 and ||4 which retain the evaporating sections in place are secured to the walls of the freezing compartment by means of screws (not shown) so that the sections and H21 may be readily removed when desired. The vapor return conduit I|8 and liquid supply conduit |88 extend through the insulated plug |48 and may be removed therewith. To remove the primary system, the evaporating sections and il! are pressed together and slipped through the opening at the rear of the freezing compartment while the condensing unit is slipped out the back of the machine compartment. Thus the entire structure may be readily removed for repairs and the like. Y

' In Fig. '1,' there is shown another modification of my invention. Numeral |58 designates in general a refrigerator cabinet having an outer metallic liner |52 and two inner metallic liners |54 and 'L55 respectively. The inner liner |54 fcrm'sfalow temperature or freezing compartment 8 while lthe inner liner v|56 forms'a food storage compartment |68. Suitable insulation |62 is interposed Vbetween the innerliners and the outer liner |52. Access to the compartments |58 and |58 is-:obtained through openings |64 and |66 which are adapted to be closed by doors Isa and nu respectively.

Numeral |14 designates in general a primary i refrigerating system similar to that shown in Figs. 4 and 5. 'I'he primary evaporator comprises two horizontal planar conduit sections |15.Y and |18 respectively which are connected in series. Section |16 is connected to the condenser (not connected to the compressor (not shown) of the primary system by means of a suction conduit |82. An accumulating chamber i 84 may be placed in the suction conduit |82 at the outlet of the evaporating section |18. The conduits |88 and |82 are preferably arranged in heat exchange relation with each other. The primary evaporating section |16 is preferably located outside the inner liner |54 of the freezing compartment |58 and is positioned in intimate heat exchange relationtherewith across the top of said liner. A metallic plate |88 is secured to `the top of the liner |54 and in conjunction therewith forms a pocket-'into which the section |15 is adapted to be inserted and held in close contact to the liner |54. The other evaporating section |18 is posishown) of the primaryv system by means of a Y, small-diameter tube |88 while the section |18`is A tloned within the liner |54 on the bottom wall thereof. A sheet metal plate |98 is secured to the bottom wall of the liner |54 and forms a pocket with the liner |54 into which this section |18 is adapted to be inserted and held in intimate heat exchange relation with the plate |88. Ice trays |82 may be placed for quick'freezing of ice cubes and the like upon this plate |88'. The two primary evaporating sections |15 and |1|I are rendered readily removable Afrom the cabinet by means of a removable closure member |86 at the rear of the compartment |58. 'I'his closure mem-` ber carries the supply and suction conduits |88 and |82 as well as the accumulating element |84. Y

Numeral 288 designates in general a secondary refrigerating system which comprises a secondary evaporator 282 and a secondary condenser 284. The evaporator 282 like those shown in Figs. 1 and 4 consists of a serpentine conduit which substantially envelopes the food storage compartrefrigerant circulates to the other evaporatingv section |18 whence it is returned in form of evaporated refrigerant to the condensing unit (not shown) to be reliqueed. The two sections |16 and |18 together serve to maintain a below freezing temperature in the compartment |58 whereby ice cubes and frozen desserts may be produced and also certain foods may be maintained in a frozen condition. The section 16 also serves to extract heat from the secondary condenser 284 whereby secondary refrigerant is condensed in the condenser 284. The liquefied secondary refrigerant as already described in the precedingrembodiments oi' my invention circulates by gravity through the secondary evaporator and cools the food storage compartment to a proper refrigerating temperature.

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 Vscope of the appended claim.

I claim:

Refrlgeratlng apparatus comprising an insulated cabinet having two sheet metal liners arranged'to provide two compartments for the storage of food, a secondary refrigerant coiled evaporator secured to the exteriorl of one of said liners, a. secondary refrigerant coiled condenser arranged Yon a single plane and secured to the exterior of the second liner, a primary refrigerant coiled evaporator arranged on a single plane in contact with the interior of said second liner directly opposite said secondary condenser and a sheet metal plate arranged to provide a support for objects to be frozen and to removably secure said primary refrigerant evaporator to said second liner.

LAWRENCE A. PHILIP?.

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