US2136316A - Refrigerating apparatus - Google Patents

Description

Nov. 8, 1938. A. PHILIPP 2,135,316

'REFRIGERATING APPARATUS Original Filed April 20, 1935 2 Sbeefs-Sheet 2 J INVENTOR. LlYhQE ICL' If PHIL/PP ATTORNEY.

- UNITED STATES/PATENT OFF-ICE aEFmGamrmG APPARATUS j Lawrence A. Philipp, Detroit, Mich., assignor, by

mesne assignments, to Nash-Kelvinator Corporation, Detroit, Mich land a corporation of Mary- Application April 20, 1933, Serial No. 666,944

Renewed January 24, 1935 I 11 Claims.

This invention relates to refrigerating .appa-j ratus and more particularl y to the method and apparatus for controlling temperatures in such apparatus.

.One of the objects of myinvention is to provide a fundamentally new of refrigeration wherein a system and method simple compact unit is utilized for freezing ice cubes and the like and for cooling circulating air in 'a refrigerator cabinet in animproved manner without the collection of frost on its surfaces exposed to said circulating air at least part of the time.

Another object of my invention is to provide a refrigerating apparatus of terms for cooling a plurality the type which ineludes primary and secondary refrigerating sysof zones, and to provide an improved arrangement for maintaining a temperature differential between said systems.

Another object of my invention is to provide a refrigerating apparatus of the type which includes a primary and secondary refrigerating system for cooling a plurality of v zones, and to provide an improved met hod for maintaining a temperature differential between said systems. Another object of my invention consists in an improved method of controlling temperatures in the primary and secondary said apparatus.

systems of the aforemary refrigerating system inoperative for periodically defrosting any part of the apparatus.

Another object of my in tion the effective area of vention is to proporthe heatdissipating portion of the secondary-condenser with respect to the heat absorbing area of the secondary evaporator to maintain a temperature differential between the heat absorbing medium of the condensing zone and the secondary evaporator.

Other objects and advantages will be apparent from the following description, reference being bad to the accompanying drawings.

In the drawings: Fig. 1 is a vertical view in cross section of a refrigerating apparatus embodying features of my invention;

Fig. 2 is a view taken a long the line 22 of Fig. 1, with a portion of the enclosure for the cooling apparatus broken away;

Fig. 3 is a view of a modified form of refrigerating apparatus embodying features of my invention; and g Fig. 4 is a further'modified form of refrigerating apparatus embodying features of my invention.

Referring to the drawings, the numeral designates, in general, an insulated cabinet having a food storage compartment 2|, the inner walls of which are formed by a metallic liner 22. Preferably, the lining member-'22 ,is provided'with a coating of vitreous enamel, such as porcelain, toprovide a neat appearance and surface which maybe easily-cleaned.

Within the confines of the liner 22 there is disposed a' refrigerant evaporating element 25 of a primary refrigerating system 21. The element 25 is of the plate type, whichmay be of any suitable construction, and is horizontally disposed in the cabinet slightly spaced from the top wall thereof. The element 25 is arranged for supporting ice making receptacles 25 on its upper surface immediately below the top wall of the cabinet .20.

In addition tothe primary evaporating element 25, the-primary refrigerating'sy'stem 21 includes a compressor 30, motor 32, condenser 34, and a high side float mechanism 36. The compressor withdraws gaseous refrigerant from the element 25 through vapor. return conduit 38, compresses the gaseous refrigerant and delivers it to the condenser wherein it is liquefied and from which it is delivered to the high side float mechanism. Liquid refrigerant is delivered tothe element 25 through a liquid supply conduit 40 under the control of float mechanism 35..

A secondary refrigerating system is provided for cooling the circulating air in the. compartment 2| and also for supporting receptacles for freezing and storing frozen substances in close proximity. to the primary evaporating element 25 where said substances will, be frozen or retained in frozen condition by the refrigerating effect of the primary evaporating element 25.

The secondary refrigerating system 42 comprises, in'general, a refrigerant evaporating element 45, the interior of which forms an evaporating region, and a refrigerant-condensing element 46, the interior of which forms a condensing region. The elements 45' and 46 are connected together and are in open communication with each other bymeans of conduits 41. The secondary refrigerant evaporating element 45 is substantially of the same size as the primary refrigerant evaporating element 25 and is horizontally disposed within the cabinet directly be- I low the element 25. The secondary evaporating element is arranged for supporting receptacles 49 on its upper surface and for cooling the circulating air in the compartment 2| by the circulating air contacting with the underside of said element. The secondary refrigerant condensing element 46 is, preferably, rectangular' 7 that the effective area for dissipating heat abfled form of condensing element for the secondary sorbed in the secondary system is considerably less than the heat absorbing area of the secondary evaporating element 45. As shown in Fig. 2, the secondary condensing element 46 is considerably smaller in size than the evaporating element 45. .By thus providing a relatively small condensing element 46, the surface thereof which contacts with the primary evaporating element will be such that only a portion of the evaporated refrigerant in the secondary system 42 will be condensed, and a portion thereof is retained in vapor form in the condenser 46 where it applies a definite pressure upon the liquid refrigerant in the secondary evaporating element 45, to thus maintain a heat lag between the secondary evaporating element and the primary evaporating element. Thus, by proportioning the eile'ctive heat dissipating area of the secondary condensing element and the heat absorbing area of the secondary evaporating element, 9. definite temperature difierential may be maintained between the primary and secondary refrigerating systems.

Referring now to Fig. 3, there is shown a modisystem 42. In this modified form of the invention, the secondary refrigerant condensing element 52 is provided for condensing evaporated refrigerant in the secondary system. As will be noted, the condensing element 52 is substantially the same size as the primary evaporating element 26. In an arrangement of this type. I also proportion the eflective area of the heat dissipating portion of the condensing element 52 with respect to the heat absorbing area of the secondary evapcrating element. In this arrangement, however, the effective area of the condenser 52 is limited by substantially entirely filling the secondary evaporating element and condensing element with liquid refrigerant so that the upper interior sur'- face of the condensing element is partly in contact with some of the liquid refrigerant in the secondary system, and some of the upper interior surface of the condensing element is slightly spaced from the liquid refrigerant in the secondary system. Thus, the upper interior surface of the condensing element 52 need not be all on the same plane but is slightly undulating so that portions thereof contact with the liquid refrigerant in the secondary system, while other portions thereof are slightly spaced from the liquid refrigerant in the secondary system. This limits the effective area of the condensing element 52.

As shown in Fig. 4, another arrangement for maintaining a temperature differential between the primary refrigerant evaporating element and the secondary refrigerant evaporating element 53 in the aforesaid apparatus is to merely introduce a slight film of liquid refrigerant 54 into the refrigerant evaporating element so that the amount thereof is insufficient to at any time cool the surfaces of the secondary evaporating element to as low a temperature as the quantity of liquid contained in the primary evaporating element cools the surfaces of the primary element.

Preferably, the temperature differential which is maintained between the primary evaporating element 25 and the secondary evaporating element 45 is such that the circulating air in the compartment 2| is cooled to the desired temperatures without collecting frost on the surfaces of the evaporating element 45 at least part of the time during its operation. This may be accomplished by operating the evaporating element 45 at temperatures which would allow the collection of a slight film of frost thereon during the onphase of the refrigerating cycle of the primary system 21, and allow the frost to be melted from the element 45 during the off-phase of the refrigerating cycle of the system 21. If desired, however, the secondary evaporating element may be operated at temperatures slightly above that which would cause the collection of frost and ice thereon due to the deposit of moisture from the circulating air in the compartment 2|.

In order to prevent the collection of frost and ice on the primary evaporating element 25 and the upper surface of the secondary evaporating element 45, and to provide suitable freezing zones for the substances contained in trays 26 and 49,'I have provided a metallic enclosure 60 and a front closure plate 62. The enclosure 60 is provided with out-turned flanges 64 which are secured to the top wall of the cabinet 2| in any suitable manner, and inturned flanges 66 which are secured to the top wall of the secondary evaporating element 45 in any suitable manner. The enclosure 68 forms a suitable enclosure for the sides and rear portion surrounding the primary evaporating element 25, the secondary condensing element and the top wall of the secondary evapor ating element 45. The front closure plate 62 cooperates with the closure 60 for so enclosing the primary evaporating element, secondary condensing element and the top wall of the secondary evaporating element against the circulating air within the compartment 2|. The front closure 62 is provided with openings 10 and II to permit the insertion and removal of the receptacles 26 and 49, respectively. The openings 10 and H are closed by doors 13 and '14, respectively.

In order to increase the heat transfer characteristics of the secondary evaporating element 45 I have provided a plurality of U-shaped heat absorbing fins 15. The fins are preferably equally spaced and arranged in parallel relation across the underside of the element 45. Immediately below the secondary evaporating element 45', I have positioned a pair of bailies and drip conducting plates 18. The members 18 are arranged for directing the fiow of air in the compartment 2|, and also for receiving the drip water from the secondary evaporating element 45 and conducting it to a drip receptacle 80 supported by shelf 82. i

From the foregoing, it will be noted that I have provided an improved arrangement and method for maintaining a temperature differential between a primary and secondary refrigerating system which is very simple to construct and'is so arranged that it consists of no moving parts whatsoever or any parts in the secondary porization reduction of'the amount of association between ondary system.

evaporating element 45. It

1 frost and ice upon system which would be'likely to become faulty in operation to vary the temperature differential maintained between it and the primary system.

I have provided an automatic thermostatically controlled switch 85, to which is conmeted a thermostatic fluid containing bulb 81,

whichcontrols the operation of the switch 85 in the well known manner. The'iluld containing thermostatic bulb 81 is placed in contact with a secondary evaporating element 45, to thus control the operation of the primary systemin response to changes in temperatures in the element 45. The switch 85 opens and closes the motor circuit to the power mains 90 in response to changes in temperatures in element 45.

Thus, it will be noted thatrpredetermined temperatures may be maintained within the evaporating element 45, by controllingthe operation of the primary refrigerating system in response to changes in temperatures in the secondary will also be noted that the relative temperatures existing in the secondary evaporating element 45 and the primary evaporating element 25 may be determined in various manners. In the embodimentsof the invention disclosed, .the heat lag between the evaporating region and the condensing region is increased by reducing the amount of association betweenmolecules of evaporated refrigerant and the condensing portion. This can be accomplished by limiting the effective area of the secondary condensing element relative to the eifec tive area of the secondary evaporator, in which case an increased pressure is present in the secondary system which in effect reducesthe vain the secondary evaporator, or, this molecules of evaporated refrigerant and the condensing portion can be accomplished by utilizing,

a small amount of refrigerant in the seconly By these arrangements, ice cubes and the like may temperature for the preservation of foods stored in the compartment 2| without the collection of its exposed surfaces, or with the collection of a slight film of frost thereon during the on-phase of the refrigerating .cycle of the primary system which is melted during the off-phase of the refrigerating cycle of the -primary refrigerating system. It will also be noted that by the arrangement of parts in the cabinet, the same element which cools the circulating air within the cabinet provides a support for receptacles containing substances to be frozen or to be retained. in a frozen condition by the refrigerating effect of a heat absorbing element which is provided for the rapid freezing of substances.

Although only a preferedforrn of the invention has been illustrated, and that form described be apparent to those skilled in invention or from claims.

What I claim as my invention is:

the scope of the appended 1. The process of refrigeration which consists in establishing refrigerant condensing andevaporating zones in' open communication with each other, maintaining .said zones substantially en- In order to con-,

be rapidly frozen by the re-.

. to the first named cooling frigerating effect of the'primary evaporating eleelement whereby the peratures above the freezing point of water, said second shelf having an air cooling portion and being provided with a surface for supportingfrozen'substances immediately below the first named shelf to thereby maintain said substances in a frozen condition by the refrigerating effect of the first named shelf.

3. Refrigerating apparatus comprisin in combination, a cooling element for freezing substances, a second cooling element having a portion located directly below the first element, and means for operating the second element at least part of the time at temperatures above the freezing point of water, said second element having an air cooling portion and being provided with a surface for supporting frozen substances immediately below the first named element to thereby maintain said substances in a frozen condition by the refrigerating effect of the first named element.

4. Refrigerating apparatus combination, a cabinet having a food storage compartment, a cooling element disposed in said cabinet-for freezing substances, a second cooling element disposed in said cabinet for cooling the circulating air in operating the first named cooling element at temperatures sufficiently low enough to cause comprising, in

rapid freezing of 'saidsubstanceaand means for operating said second named element; at temperatures above that which would permit operation without collecting frost and ice thereon at least part of the time, and said second named cooling element being so positioned with respect element that frozen substances may be supported thereon to be retained in a frozen condition by the refrigerating eflect of the first named cooling element.

5. Refrigerating apparatus comprising, in combination, a cabinet, a pair of vertically spaced plate type evaporating elements disposed in said cabinet and being adapted to support ice making receptacles one above the other, means enclosing the upper element and the uppermost part of the lower element from the circulating air in the cabinet, and means for operating the lower element at a higher temperature than the upper underside of the lower element may cool the circulating air in said cabinet without collecting frost thereon at least part of the tim andthe upper surface thereof may be used for supporting one of said ice making receptacles for freezing the contents thereof by the refrigerating effect of the upper element.

6. Refrigerating apparatus comprising, in combination, a cabinet, a pair of vertically spaced element whereby the underside of the lower element may cool the circulating air in said cabinet from the. circulating 'air in for operating the lower ele- 3 ment at a higher temperature than the upper said compartment, means for e without collecting frost thereon at least part of the time, and the surface thereabove providing a support for one of said ice making receptacles for freezing the contents thereof by the refrigcrating effect of the upper element, and means responsive to changes in temperatures of the lower element for controlling the refrigerating effect of the upper element.

'7. Refrigerating apparatus comprising, in combination, a cabinet having a food storage compartment, a primary refrigerating system including a refrigerant evaporating element disposed in said cabinet outside of direct contact with the circulating air in said compartment, a secondary refrigerating system including a refrigerant evaporating element disposed in the path of circulating air in the food compartment for cooling said air, said secondary system also including a condenser disposed in contact with the primary element, said secondary system being substantially entirely filled with liquid refrigerant to thereby produce a heat lag between the primary and secondary evaporating elements-so that the secondary evaporating element operates at least part of the time without collecting frost thereon, and means for controlling the operating of the primary system in response to changes in temperatures in one of said systems.

8. Refrigerating apparatus comprising a cabinet having an insulated main food chamber, a

v refrigerating system comprising a coolingunit in said chamber, said unit including an enclosure having surfaces exposed for cooling circulating air in said chamber, and a refrigerated shelf positioned in said enclosure to divide the interior thereof into a relatively small freezing chamber and a relatively large storage chamber, and to refrigerate said enclosure, the exposed surfaces of said enclosure being so associated with said refrigerated shelf asto cool said main chamber to a refrigerating temperature, solely by the heat absorbing effect of said refrigerated shelf without the formation of ,frost thereon at least part of the time while the refrigerated shelf is maintained at a sharp freezing temperature.

9. Refrigerating apparatus comprising a cabinet having an insulated main food chamber, a refrigerating system comprising a cooling unit in said chamber, said unit including an enclosure having surfaces exposed for cooling circulating air in said chambenand a refrigerated shelf positioned in said enclosure to divide the interior thereof into two chambers, and means associated with said enclosure for controlling the temperature of said refrigerated shelf, said means being responsive to the changes in temperature of a surface ofsaid enclosure to maintain a refrigerating temperature in said main food chamber solely by the heat absorbing eifect of said refrigerated shelf without the collection of frost on the exterior surfaces of said enclosure at least part of the time while maintaining the refrigerated shelf at a'sharp freezing temperature.

10. Refrigerating apparatus including a cooling unit adapted to be installed in an insulated food storage chamber comprising a metallic casing forming a secondary chamber, shelf means within said secondary chamber dividing the same into compartments of unequal height, means for refrigerating said shelf .means, said secondary chamber having access means for said compartments and closure means for said access means, and means influenced bythe temperature of said metallic casing for controlling the refrigerating effect of said shelf refrigerating means, said shelf refrigerating means being arranged to refrigerate at least the compartment above said shelf to temperatures below freezing and to absorb heat from said casing to refrigerate the food storage chamber without the formation of frost on said casing.

11. Refrigerating apparatus including a cooling unit adapted to be installed in an insulated food storage chamber comprising a metallic casing forming a secondary chamber, refrigerated shelf means within said casing for dividing said secondary chamber into a plurality of compartments and for refrigerating the same, and means including a thermo-bulb contacting a surface of said casing for controlling the refrigerating effect of said shelf means, said casing being arranged to refrigerate said insulated food storage chamber, without the collection of frost on said casing at least part of the time, solely by the refrigerating effect of said shelf means.

LAWRENCE A. PHIIIPP.

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