US2309797A

US2309797A - Refrigerating apparatus

Info

Publication number: US2309797A
Application number: US407621A
Authority: US
Inventors: Carl A Stickel
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1941-08-20
Filing date: 1941-08-20
Publication date: 1943-02-02
Anticipated expiration: 1960-02-02

Description

Feb. 2, 1943. c. A. STICKEL.

RFRIGERATING APPARATUS Fi'led Aug. 20, 1941 al; f4?

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//H////// /f ///////////0//N//// /f/ 3m/f /f/ /W /Vf Patented Feb. 2, 1943 REFRIGERATING APPARATUS Carl A. Stickel, Dayton, Ohio, assignor to General Motors Corporation, Dayton,

tion of Delaware Ohio, a corpora- Application August 20, 1941, Serial No. 407,621

Claims.

This invention relates to refrigerating apparatus and particularly to a two-temperature :refrigerator cabinet. o

.An object of my invention is to provide an improved two-temperature refrigerator' cabinet.

Another object of my invention is to provide an improved and more efficient manner of refrigerating a two-temperature refrigerator cabinet of the type wherein a portion of a secondary refrigerant circuit is associated with a part of a primary refrigerating system and is employed to cool the interior of the uppermost compartment of superimposed compartments in the refrigerator cabinet.I

A further object of my invention is to associate a primary refrigerating system, having two evaporators disposed one above the other, with a two-compartment refrigerator cabinet wherein the lowermostof the evaporators is employed to cool the lower compartment of the cabinet, and the other or uppermost evaporator is utilized to render a, closed secondary refrigerant circuit elective to cool the upper compartment of the cabinet and to provide the primary refrigerating system with a multiple effect compressor for withdrawing refrigerant directly and simultaneously from both primary evaporators to thereby maintain the temperature differential between the two compartments substantially uniform.

A still further and more specific object of my invention is to provide forl the detachment of the primary evaporator in a system of the type described in the preceding object from the condensing portion of the secondary refrigerant circuit and for the removal of the primary refrigerating system as a unit from the cabinet.

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

In the drawing:

Fig. 1 is a vertical sectional view of a refrigerator cabinet having my invention embodied therein; and

Fig. 2 is a diagrammatic showing of the refrigerating systems associated with the refrigerator cabinet disclosed in Fig. 1.

Referring to the drawing, for illustrating my invention, I have shown in Fig. 1 thereof a'refrigerating apparatus of the. two-temperature CII household type. A cabinet I0 has aplurality of outer metal panels or wallsfII and'jan inner'.

Any suitable or desirable insulating material I3 is disposed between the liner I2 and walls II of cabinet I0 to insulate the chamber therein. Liner member I2 has an aperture therein regis` tering with an aperture formed in the front wall II of cabinet I0 to provide an access opening for the chamber. Breaker strips I4 of any Vsuitable or desirable insulating material overlap the edge portion of the aperture in the cabinet -front wall and the spaced edge portion of the aperture in liner I2 to provide walls of the access opening. These breaker strips I4 are removably secured in place in any convenient or conventional manner for a purpose to become apparent hereinafter. The chamber within cabinet I 0 is divided into an upper food storage compartment I6 and a lower food storage or freezing' compartment II by a. removable glass plate or the like partition I8. Partition I8 has a rubber or the like gasket member I9 secured to all four edges thereof, and the gasket I 9 engages the three vertical walls of liner I2 and the inner face of an insulated door structure 2I which normally closes the access opening to the cabinet chamber. The engagement of gasket ,I9 with walls of liner I2 and the door 2l causes partition I8 to isolate the compartments I6 and I1 from one another. The outer cabinet walls II depend below the insulated chamber and form a machine compartment 22 in the bottom of the refrigerator cabinet for housing a. refrigerant liquefying and circulating unit of a primary refrigerating system. An opening provided in the front of the machine compartment 22, for a purpose to be hereinafter described, is closed by a cover or door 23.

The primary refrigerating system associated with the refrigerator cabinet I0 includes a rst evaporator in the form of a conduit loop 2B which is disposed in the insulation I3 at the top of cabinet I0, under the breaker strip I4, and another or second evaporator 2l located below the rst evaporator 26 and disposed within the lower compartment I1. Evaporator 2'I is preferably of the sheet metal U-shaped variety wherein refrigerant expansion passageways are formed intermediate two secured together metal plate members. The refrigerant liquefying and circulatingV unit of the primary refrigerating system is mounted in the machine compartment 22 and lcomprises a sealed motor-compressorv unit 28 .and` ia, condenser 29. In the present disclosure, fthe compressor 3l of unit 28 (see Fig metalliner member I2 spaced therefrom and Y forming walls of a chamber withinthe cabinet."y

192,846, filed February 26, 1938. This compressor 3| has separate refrigerant gas

return conduit connections

32 and 33, with each of the

evaporators

26 and 21 respectively for simultaneously withdrawing refrigerant therefrom. Refrigerant compressed by the compressor 3i of unit 28 is forwarded under pressure, through a pipe 34, to condenser 26 where it is cooled and liquefied in any suitable or desirable manner. The liquid refrigerant is circulated to the upper or irst evaporator 26 by way of a long smalldiametered pipe 36 which restricts or controls the flow of refrigerant into evaporator 26. Restrictor pipe 36 is connected to a depending end portion 31 of the larger conduit 26 of the upper evaporator, and some of the refrigerant upon entering this evaporator begins to evaporate while the remainder thereof stays in liquid form and is conveyed to the lower or second evaporator 21 by way of another long, small diametered pipe 38. Pipe 38 extends into the end portion 31 of evaporator 26 and communicates with the open end of pipe 36. This pipe 36 restricts or controls the feeding of liquid refrigerant from evaporator 26 into evaporator 21. 'I'he expanding or evaporating refrigerant entering the conduit evaporator 26 causes same to produce a refrigerating effect for a purpose to be hereinafter described. Refrigerant expanding into or evaporating within the lower or second evaporator 21 causes this evaporator to produce a refrigerating effect to cool the lower compartment I1. The temperature of evaporator 21 is at all times maintained below freezing in order to freeze water or other substances placed in trays and adapted to be located. thereon. The cooling of compartment I1 at such lowA temperature causes frost to form on walls of the primary evaporator 21, which also causes dehydration of the air within the compartment and the maintenance of a low relative humidity therein. Starting and stopping of the electric motor of the motorcompressor unit/26 may be carried out in response to the temperature produced by evaporator 21. Thus, I locate a thermostatic bulb 4I within compartment I1 adjacent a wall of evaporator 21 and connect this bulb, by a pipe 42, with an expansible and contractable bellows 43 forming part of a snap-acting control switch 44 (see Fig. 1). Switch 44 is conventional and controls an electric circuit to the unit 28 to start and/or stop operation of the electric motor and consequently the multiple effect compressor 3I of the primary refrigerating system.

A closed secondary circuit containing a volatile liquid refrigerant is associated with the refrigerator cabinet I6 and comprises a refrigerant condensing portion 46 in the form of a conduit thermally contacting the upper evaporator 26 of the primary refrigerating system. Removable clamping means (not shown) may, if desired, be utilized for holding the condenser portion 46 of the secondary circuit in intimate thermal contact with the primary evaporator 26. A liquid feeding conduit 41 is connected with the condensing portion 46 of the secondary circuit and extends downwardly therefrom for feeding condensed liquid refrigerant to an evaporating portion 48 of the secondary circuit. The evaporator or evaporating portion 48 of the secondary circuit comprises a plurality of conduit loops secured to and extending over the outer surfaces of liner f asoavsv trap 46 formed therein connects the evaporating portion or loops 48 of the secondary circuit with the condenser 46 thereof as is customary in such systems to cause all liquid condensing in condenser 46 to drain directly into the feeding conduit 41. It will be noted that the greater portion of the secondary circuit is disposed below the level of the first or upper evaporator 26 of the primary refrigerating system and that the refrigerant evaporating portion 46 of thesecondary circuit is located above the second or lower primary evaporator 21. Volatile refrigerant evaporating within the portions 48 of the secondary circuit cools the walls of the upper food storage compartment I6 of cabinet I8 and maintains the interior of this compartment at a temperature above freezing to thus minimize convection currents therein. The interior of compartment I6 is maintained between certain temperature limits in accordance with the normal temperature limits of the primary evaporator 21 by association of condenser 46 of the secondary refrigerant circuit with evaporator 26. When refrigerant is withdrawn from evaporator 21 by the multiple effect compressor 3|, refrigerant is also withdrawn from evaporator 26 to render the evaporating portion of the secondary circuit effective to cool compartment I6. Refrigerant, after evaporating and flowing upwardly in the loops 48 of the secondary circuit enters the condenser 46 by way of trap 49. This evaporated refrigerant is condensed and liquefied by the refrigerating effect or low temperature of the upper primary evaporator 26 and the liquefied refrigerant then flows downwardly from condenser 46 by way of the liquid feeding conduit 41 to the lowermost evaporating loops 46. In a structure of the type disclosed, it is the purpose of parti-l tion I8 to divide the cabinet chamber into two compartments wherein the one or lower compartment I1 is maintained at a low or freezing temperature and low relative humidity in the' manner described and wherein the other or upper compartment is maintained at a higher temperature and consequently high humidity for providing a two-temperature cabinet for the storage of various food products.

The multiple effect compressor 3l of the primary refrigerating system withdraws low pressure refrigerant, by way of conduit 33, from evaporator 21 and at the same time withdraws high pressure refrigerant, by way of the separate conduit 32, from the upper evaporator l26. The use of the multiple effect compressor in a system of the type disclosed provides for more efficient handling of the refrigerant of the primary system and provides quicker response of the secondary refrigerant circuit to cool the high temperature, high relative humidity compartment I6 and thereby maintains a more uniform temperature therein. As shown in Fig. 2, it will be noted that the low suction pressure port entering the compressor 3I from conduit 33 is disposed in close proximity to the compressor blade while the relatively higher suction pressure port entering the compressor from conduit 32 is disposed at an angle thereto as is customary in conventional multiple eifect compressors. Thus, by providing the primary refrigerating system with separate gaseous refrigerant return conduits and by connecting these conduits with a multiple effect compressor, refrigerant is simultaneously withdrawn from the

primary evaporators

26 and 21 to thereby render the secondary refrigerant circuitmore directly responsive to cooling produced bythe primary Vrefrigerating system. p

In tliegpresent structure I have located the

conduits

26, 32, 33, 36 and 38 of the primary refrigerating system in the. front portion of cabinet l vso as toprovidefor the removal of the primary refrigerating system as a vunit outwardly from thefront of` the cabinet. For exf ample, the conduitsrfare disposedin the insulation I3 directlybeneath the door opening breaker strips orwallsiM-.alongfa side and the top vof the laccess 1: e l stantially'injthe--manriershovvrr and describedV ningtoV thecabinet chamber subin: the v McCormack-et all; Patent No. 2,010,924

'dated August i l3`,fl'93;5 upon detachment fofy the chainber*access-` opening walls'flfrom the cabinet,v access` ma'yfbeV had to, thev conduits 26, V32,- 33, 36 and 38. to withdraw theseconduits through the spacev between" the outer wall Il andliner I2 so that they may be removed along with the evaporator 21 and'unit28'of the pri-` mary refrigerating system outwardly from the front of the cabinet. In removing the elements of the primary refrigerating system as a unit from cabinet l0, the electric wires intermediate switch 44 and unit 28 are disconnected to enable switch 4d to remain in the cabinet. Any damage or inoperativeness of the primary refrigerating system can readily be remedied by the removal thereof from the cabinet and the replacement into the cabinet of another unit or system as is customary in present-day installations.

From the foregoing it will be apparent that I have provided an improved and more efiicient' lower of the compartments of the refrigerator cabinet and by simultaneously withdrawing refrigerant from both primary evaporators through separate conduit connections with a multiple effect compressor. The contact between the one primary evaporator and the condenser of the secondary circuit is predetermined to thereby insure the maintenance of a substantially constant temperature and high relative humidity within the higher-temperatured upper storage compartment of the cabinet.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1.I A refrigerating apparatus comprising in combination, a cabinet having an upper food storage compartment and a lower food storage compartment therein, a closed primary refrigerating system including a first evaporator in the upper part of said cabinet and a second evaporator disposed in heat exchange relationship with said lower food compartment for cooling same, a closed secondary refrigerant circuit containing a volatile liquid and including acondensing portion in intimate heat exchange relationship with said rst primary evaporator and an evaporating portion located therebelow and disposed in heat exchange relationship with said upper food compartment for cooling same, f conduit means for conveying refrigerant f roin said first primary evaporator to said secondl pril mary evaporator. and said primary refrigerating system including a multiple effect compressor having separate conduit connections with each of said evaporators thereo frigerant directly therefrom.

y 2. A refrigerating apparatus *comprising* combination, a cabinet having anI upper food.,

storage compartment and avlower food storage compartment therein, a closed primary refrigerating system-'including-a first evaporatorin the upper part of said cabinet -and a second evap orator disposed withinfsaid lower food compartment for cooling same, a closedsecondary refrigerant circuit :containing a volatile liquid and including a condensingfportion in intimate heat exchange relationship'with said first primary evaporator and an evaporating portion located..

therebelow and disposed in intimate thermal contact with walls of said upper compartment forcooling the interior thereof, conduit means for conveying refrigerant from said first primary evaporator to said second primary evaporator,

and said primary refrigerating system including y a multiple effect compressor having separate conduit connections with each of said evaporators thereof for withdrawing refrigerant directly therefrom.

3. A refrigerating apparatus comprising in icombination, a cabinet having a plurality of walls forming a chamber therein, said chamber being provided with an access opening normally closed by a door. means cooperating with the `inner face of said door and with the upright wallsof said chamber for dividing the chamber into an upper food storage compartment and a lower food storage compartment, a closed primary refrigerating system including a rst evaporator in the upper portion of said cabinet and a second evaporator disposed in heat exchange relationship with said lower food compartment for cooling same, a closed secondary refrigerant circuit containing a volatile liquid and including a condensing portion in intimate heat exchange relationship with said first primary evaporator and an evaporating portion located therebelow and disposed in heat exchange relationship with i ating system including a multiple effect compressor having separate conduit connections with each of said evaporators thereof for withdrawing refrigerant directly therefrom.

4. A refrigerating apparatus comprising in combination, a cabinet having a plurality of walls forming a chamber therein, said chamber being provided with an excess opening normally closed by a door, removable means cooperating with the inner face of said door and with the upright walls of said chamber for dividing the chamber into an upper food storage compartment and a lower food storage compartment, a closed primary refrigerating system including a first evaporator in the upper'portion of said cabinet and a second evaporator disposed within said lower food compartment for cooling same, a closed secondary refrigerant circuit containing a volatile liquid and including a condensing pori for withdrawing rev-2v tion in intimate heat exchange relationship with said first primary evaporator and an evaporating portion located therebelow and disposed in intimate thermal contact with walls of said upper compartment for cooling the interior thereof, conduit means for conveying refrigerant from said first primary evaporator to said second primary evaporator, and said primary refrigerating system including a multiple effect compressor having separate conduit connections with each 10 oi' said evaporators thereof for withdrawing refrigerant directly therefrom.

l5. A refrigerating apparatus comprising in combination, a cabinet having an upper food storage compartment and a lower food storage compartment therein, a closed primary refrigerating system including a first evaporator in the upper part of said cabinet and a second evaporator disposed in heat exchange relationship with said lower food compartment for cooling same, a closed secondary refrigerant circuit containing a volatile liquid and including a con-y densing portion in intimate heat exchange re lationship with said first primary evaporator and an evaporating portion located therebelow and disposed in heat exchange relationship with said upper food compartment for cooling same, and said primary refrigerating system including a multiple eiect compressor having separate conduit connections with each of said evaporators thereof for withdrawing refrigerant directly 15 therefrom.

CARL A. BTICKEL.