US2610479A - Two-temperature refrigerator - Google Patents

Description

Patented Sept. 16, 1952 :George IWashta.Nutley, N. J., lassignor to. Admiral Corporation, Chicago, Ill.\a corporaforigiar application.. J

uly '14,' 1943, Serial No.1

494,629+nowfPatent No. 2,511,851, dated June.

20, .19510: .Dilvidedl'and this application June 16, 21950;;SerialNo,l-16&,595

This inventionrelates .to refrigeratorsfandparticularly to refrigerators of theftype havingtwo.

food storage compartments. to. be maintainedl at differentl temperatures; .applieationis a division of the copending application. of; George K. Iwashita, Serial No. 4921,629`,`, fi1'e,d'..lu1f '14 1943 and issued on June 2,024 195.0. into. Patent No. 2,511,851.

The principal objectief. this. invention. isi to provide, anv improved multilfcompartmenb, )multitemperature refrigerator.. which. has. advantages inA constructionA andV .operation .not possessed' by. prior art refrigerators.-

Another object. ofjtheinventionis to provide an. improved twoA vtemperature yreirigerator. hav.- ing a singlev primaryand. dual secondary, riefrigerantcirculating circuits.,

Another obj ect. isto provide. an .improved two temperature refrigerator. .havinga single primary refrigerant circulatingt circuit. provided: withV a single evaporator andldual vsecohdary` refrigerant circulating circuits,y each provided' with a single evaporator and. a single? condenser portion and in which theheat absorbing .characteristics of the two secondary .condensers arezmaintainedat predetermined `relative values;

pStill another object oi this inventionjistojpro'- videwaV two temperature refrigerator havin'ga' single primary`refrigerant"circulating'circuit ,providedfwith .an evaporatorA and" dual ,Secondary refrigerant circulatinggcircuits; eachhavingasecondary condenser maintained in` heati exchange relation with the primaryevaporator; the, difference inV the temperatures of the refrigerated compartments beingA maintained by'adifference f in effectiveness of' the heat transferbetweentthe' primary evaporator and ea'chof; thetwosecondarycondensers.

' IStill another object'of this''invention:isi-to"proL vide an improved multi-temperature;gmultiecom'- partment refrigerator of the ytype having the above recited advantagesv and vwherein the'primary refrigerant circulating circuit'is removable;

Other objectsand advantages Willbecornelapparent from thefollowing Vdescription' taken i-n conjunction with the drawing wherein:

Fig. 1 is an elevational view'o'f a refrigera-torl constructed according -t'otli'e'- present'- invention showing the'door which'-closes-theaccessopenings to the two compartments-"standing open; and

Fig. 2 is a longitudinali-medialvsection on Aan enlarged scale showing thearrangement of: the refrigerant circulatingV circuits and thadisposition of the two food storage compartments relative toeachother. ,Y

=Inv i the i drawing :ttiei refer'eneez' character I 0 2' designates. arefrigerator which is 'provided with. an upper. main food storage compartmentY I2 and a lower. compartment' |.41` which is vtcrbe'maintained at, a lower temperature than the upper compartment and is frequently called a frost chest. The...-frost chest I4- is for the freezing of. ice cubes .and foods. and forv the storage of frozen. foods. The .food storage compartment I2isformed,l by a ,metallic liner I6. havingits forward', flanged edge I secured to" a; frontv sup"- portingfframelll which is preferably Inade'of a thermal! insulating. materiali Inv a similar V fas'lfiion. the frost. chest. I4'y 's formedbya yn netallic liner -2/25 havingitsA forward' hanged" edge 24 se` curedto the frame. 20S The. frame ZDj'has apart positioned between `'the frost. chestl liner 2 2; vand the. .storage 4 compartment liner [6' andjthus thermally .insulates these liners. fromL each other' at the .front of the cabinet'.

The. cabinet Ill" includes' an outer metallic .shell 26 .which vis secured i. to .the frame 2li`-and aire ar panel 2B" which is Vremovairly` securedk by' screws 3.01130 an inturned flange'il .of the 'gouter-shell 2G.

The access'openings'l tothe C OIlrllJart'mentsv l2 and 1.4 are closed by' a vthermally'insulatedrdoor l3i which when] `closed'v is' sealed against the `face of' the' cabinet'by a deformable sealing gasket 361.' carriedladjacent the periphery of 'thedoor'. The space betweenthe sii-c1126 'and the Aliners IB' andvv 2 2 is lled'jwithf athermal insulating -materi'al'SBl which" may" b ej" off any. of several' Awell known .typesj suchv as' roelwool, balsa wooly and tlielike;v BelowV theffrost chest' IIf-the'vref'rigerator cabinet is' providedwithl a. machinery compa-rtment 4'0" which' houses' a'` refrigerator' liquefying mech'ariisrznj.421'4 consistingiof-a compressor- 414; and condenser 462 Theimaehineryf compartment is closed atf'its'top lby lawalll li'seeuredto the-frame Ziland tofthe` outer liner 26 and to'v. the rear "panel- 28l` isremovably 'secured 'by- 4thevpreviouslyvmentioned screws .Sti The .machinery compartment llll'- ifs closed atl the front.. of "the cabinet panel'lll. Y

'IheY` cooling system comprises a, primary ree frigerant circulating syst-emlV-which. includes theprev-iously Y'mentionedcompressor;i121anticondenservliti,- andlf .ai pair ofiise'condary Vrefrig erator circulatingsystem's, 54 fand .5.6i

The:.pr'imartz.-(circuitv 5,2' 4has: azsingle evaporator coil L :5 8.- which is. connected :to the, outlet. ,sida of th? 'liqllfy-ng. miti 4.2.- by.' apical-hillary mhd-:6191; mr. the-sedetside-.cr 1t. eieraeorator @Spiacennected: tol thef inlet-cfu t r.;i r n arlv condense-r..- 44 by? :ap-.suction` tubeJ -62u Throughout-.1 the greater por-tionof .-tneir-,-.lerreti1ette tubes-513 andi-@Zelle Preferably? @Tweed 101' 1 "fl "Qotfr: SQ hat the suction tube will cool the relatively warm capillary tube. The evaporator coil 58 is secured to one face of a heat transfer plate 6ft, the function of which will become apparent hereinafter.

The secondary system 56 includes an evaporator coil E6 which is secured in heat transfer relation with the outer surface of the liner 22 of the frost chest I4. Y of a downwardly extending tube 98, to the outlet side of a condenser coil lil, the inlet side of which is connected by means of the tube 'i2 to the outlet side of the evaporator coil Se. The primary evaporator coil 58 and the secondary condenser The complete primary system is removable from the refrigerator through the back thereof. To do this it is necessary to remove the rear panel 28 of the refrigerator cabinet so that `thatpart of the insulation designated by the reference character 88 immediately adjacent the panel 28 may It is connected by means fcoil 'I9 are confined between the previously menv in so far as is possible, as shown in Fig. 2. Thus the thermal conductivity between the primary evaporator and the secondary Condenser of the refrigerant circulating circuit 59 is extremely eicient.

The secondary refrigerant circulating system 54 includes an evaporator portion '5'5 in heat transfer relationwith the outer surface of the liner IB, and a condenser portion 'I8 mounted on a metallic heat transfer plate 80. The inlet side of the condenser coil 'I8 is connected to the outlet of Vthe evaporator coil 'I6 by means of a tube 82, and the inlet side of the evaporator coil 'I6 is connected to the outlet of the condenser coil 'I8 by means of downwardly extending inlet tube Sil. The heat transfer plate SQ to which the condenser coil 'I8 is secured is not in direct contactrwith either of the plates t4 or I4 but is thermally connected thereto by means of metallic spacers viit which are confined between the plates 88 and 7d. Because the condenser I0 of the secondary system 56 for the frost chest I4 is in direct heat exchange relation with the primary evaporator 58 and the condenser 'I8 of the secondary system 54 for the compartment I2 is in heat exchange relation with the primary evaporator 58 only through the spacers 8S, a desired temperature diiferential between the frost chest I and the compartment I6 is maintained. The degree of temperature differential between the compart-v ments can be adjusted or regulated by choosing spacers 86 of the proper number, type and size to maintain the heat exchange rate for the compartment I4 above the heat exchange rate for the compartment I2 at a predetermined desired ratio.

' It should be noted that the outlets from the secondary condensers are above the Ainlets to the primary evaporators and below the condenser inlets so that the flow of refrigerant in the second-I ary tubing will always be in the same direction and so iiow obstructions will be created.

The above described system provides an extremely simple primary circuit, since the system requires but a single primary evaporator. It has the advantage that the primary be completely sealed and is easily removable from the cabinet for servicing, and that the secondary circuits are so arranged as to have a constant refrigerant circulation according to the principles of fluid flow. Furthermore, the temperature differential between the compartments is not maintained by the use of a differential pressure valve as is'customary in many prior systems,` but is merely maintained by means of a diiference in the eifec' tiveness of heat extraction by the primary system.

between the two secondary systems. Y

partmentrefrigerant coil than in the case of theA from the back of the cabinet.

be removed to expose the heat transfer plate 64 and the evaporator coil 58. The tubes B9 and 62' pass through a closure plate 99 which is removably secured-by means of sheet metal screws 92 to the plate 48 to close a slotted opening 94 therein. This closure plate is removed with the tubes 60 and 62, and the primary system may be removed The liquefying unit 42is secured to a frame 96 in the machinery compartment by any suitable readily detachable means. Thus the primary system is very simply removed from the cabinet for servicing or replacement. Y Y

All of the objectivesV which were enumerated in the opening paragraphs are embodied in the refrigerator of this invention. It will, however, be apparent to those skilled in the art that numerous modifications may be made in this refriger-l ator without departing from the fundamentalV principles of the invention, which is to belimitedv only by the scope of the appended claims.

Whatis Aclaimed. as newrand desired to be secured'by United States Letters Patent is:

l. A refrigerator comprising a liner forming a low temperature compartment, a refrigerant coil having an evaporator portionin heat exchange transfer with said low temperature compartment liner, a liner forminga higher temperature compartment, a refrigerant coil. having an evaporator portion in heat transfer relation with said higher temperature compartment liner,V and av sealed primary refrigerating system including an evaporator removablymaintained inrheat transfer relation with the condenser portions of both the low temperature compartment refrigerant coil and. the high temperature compartment refrigerant coil, the heat transfer fromeither condenser being accomplished through metallic heat con,

ductors, and the distance through the metallic heat conductors between the secondary condenser andthe primary evaporator being substantially greater in the case ofthe higher temperature comlower temperature compartment refrigerant coil.

2. A refrigerator comprising Va liner forming a low temperature compartment, a refrigerant coil having an evaporatorportion in heat exchange transfer `with said low temperature com-Y partment liner., a liner forming a higher temperature compartment, a refrigerant coil having an evaporator portion in heat transfer relation with said highertemperature compartment liner,

f a sealed primary refrigerating system including an evaporator coil removably maintained in Vheat transfer relation with the condenser portions ofv both the low temperature compartment refrigerant coil and the high temperature compartment.

refrigerant coil, and spaced metallic heat conductors through which heat transfer is effected higher temperaturecompartment vrefrigerant coil than in the ,case ofv the lower ,temperature compartment refrigerant coil. i'

' 3. A `refrigerator :comprising `a linergformingY a low temperature compartment, a refrigerant `coil having an evaporator portion in heat exchange transfer with said low temperature compartment liner, a liner forming a higher temperature compartment, a refrigerant coil having an evaporator portion in heat transfer relation with said higher temperature compartment liner, a sealed primary refrigerating system including an evaporator coil in heat transfer relation with condenser portions of both the low temperature compartment refrigerant coil and the high temperature compartment refrigerant coil, and metallic heat conductors interposed between said primary evaporator and said secondary condensers, the distance through the metallic heat conductors between the secondary condenser and the `in a second temperature range which is `higher than said first temperature range, each of said secondary systems having a condenser portion, means for eecting direct heat, transfer between said primary evaporator and the condenser for the secondary system adapted to cool said first compartment, and means for effecting indirect heat transfer between said primary evaporator and the condenser for the secondary system adapted to cool said second compartment so' that said first compartment is cooled to a lower temperature than said second compartment.

5. In a refrigerator having means forming a first compartment and means forming a second compartment, a primary refrigerant circulating system including an evaporator, a pair of secondary refrigerant circulating systems, one of said systems being adapted to cool the first compartment to within a first temperature range and the second of said systems being adapted to cool the second compartment to within a second temperature range which is higher than the first temperature range, each of said secondary systems having a condenser portion, and thermally conductive means between said primary evaporator and said secondary condensers, said thermally conductive means being so constructed and arranged that the heat transfer path between said evaporator and the condenser of said secondary system for the higher temperature compartment is longer than that between said evaporator and the condenser of said secondary system for the lower temperature compartment, whereby said first compartment is cooled to a lower temperature than said second compartment.

6. In a refrigerator having means forming a first compartment and means forming a second compartment, a primary refrigerant circulating system including an evaporator, a pair of secondary refrigerant circulating systems, one of said systems being adapted to cool said first compartment and the second of said systems being adapted to cool said second compartment, each of said systems having a condenser portion, thermally conductive means for effecting heat trans- -fer between said primary evaporator and one of said secondary condensers, and the other thermally conductive means for effecting heat transfer between said primary evaporator and the other of said secondary condensers, said last named means having a smaller heat transfer capacity so that one of the compartments is cooled to a lower temperature than the other compartment.

GEORGE K. IWASHITA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,798,951 Munters Mar. 31, 1931 1,865,513 Gaugler July 5, 1932 1,926,384 Hull Sept. 12, 1933 2,035,573 Smith Mar. 31, 1936 2,101,656 Steenstrup Dec. 7, 1937 2,309,797 Stickel Feb. 2,1943 2,405,392 Atchison Aug. 6, 1946 2,416,354 Shoemaker Feb. 25, 1947 2,416,777 Schweller Ma1". 4, 1947 FOREIGN PATENTS Number Country Date 575,535 Germany Apr. .28, 1933

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