US2182824A - Refrigerating apparatus - Google Patents

Description

Dec. 12, 1939. s. M. SCHWELLER REFRIGERATYING APPARATUS Original Filed March 25, 1933 2 Sheets-Sheet 1 I by,

Dec. 12, 1939. s. M. SCHWELLER 2,182,824

REFRIGERA TING APPARATUS Origin al Filed March 23, 1933 2 Sh t -sh t 2 I I n! n 'Illllll III %N OR ATTORNEY$ at... Dec. 1 2, 1 939 UNITED STATES PATENT EOFFIC areas I v nnrmcsaa'rmc .mm'rns Application 13 Claims.

This invention relates to refrigeration and more particularly to a refrigerator compresor which operates continuously during the entire period of refrigeration requirement.

It is among the objects of this invention to provide a method of refrigerating a cabinet or the like and an apparatus for carrying out the method, in which the cabinet and the refrigerating system are so combined that the compressor can operate continuously during the entire period of refrigeration requirement of the cabinet and yet in which the temperatures desired in the cabinet may be easily and positively maintained without undue loss of power and without undue complications.

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 vertical cross-sectional view of an apparatus embodying features of this invention;

Fig. 2 is a view, partly in cross-section and partly diagrammatic of another apparatus;

Fig. 3 is a vertical cross-sectional view of a modification form of the invention shown in Fi 1;

Fig. 4 is a vertical cross-sectional view of a portion of a form similar to that shown in Fig. 3, but slightly modified;

Fig. 5 is a vertical cross-sectional view of on of the evaporators shown in Figs. 2, 3 and 4; and

Fig. 6 is a vertical cross-sectional view of a detail.

Refrigerating apparatus and method embodying features of my invention are illustrated in Fig. 1, in which a cabinet,-generally designated as H! is refrigerated by a refrigeratingsystem including a compressor II, a condenser I2 and an evaporator l3 arranged in a closed cycle. The refrigerant flows from the compressor H to the condenser l2 and from thence, in liquid form,

through the line It and through an interchanger.

It to an".expansion valve I6. From thence the refrigerant flows through the evaporator i3 and returns to the compressor through the line H. Under ordinary operation, the compressor II is driven continuously during the entire period of refrigeration demand by means of the electric motor ll, which may be a constant speed alternating current motor of the usual type. No switch, thermostatically responsive to temperatures within the cabinet or system need be provided for starting or stopping the compressor.

March 23, 1933, Serial No. 682.304 Renewed February 23, 1939 In the embodiment shown in Fig. 1, the cabinet I0 is provided with a food preserving space I9 within which the evaporator I3 is placed, and with a freezing space (not shown but similar to the space 32 hereafter described) within the hollow portion of the evaporator l3, preferably in the form of ice tray sleeves, now well known in the art. The system is controlled to maintain the desired temperatures in the food preserving space and the "freezing space notwithstanding the continuous operation of the compressor. The temperature in the freezing space 20 generally is desired to be substantially below 32 F. and the temperature in the food preserving space 89 generally is desired to be above 32 F., and generally below F.; but it is to be understood, that under varying conditions, the temperature requirements may be entirelydifferent from those above specified. In order to maintain the desired temperatures, the evaporated refrigerant flowing from the evaporator [3 to the com-- pressor Ii is throttled by a throttle valve 2|, which throttle valve 2! is preferably of the thermostatic bulb variety, several of the details of which are shown in Fig. 6, and in which the thermostatic bulb 22 is made responsive not only to the temperature of the food preserving space l9, but also, because of its proximity to or contact with the ends of the ice tray sleeves, is also made responsive to the temperatures of the ice freezing space.

In the operation of the apparatus shown in Fig. 1, condensed liquid refrigerant flows through the line It to the heat interchanger l5 where it iscooled by the returning evaporated throttled refrigerant and from thence passes to the expansion valve I 6. From thence the refrigerant flows through the evaporator l3 simultaneously cooling the food preserving space I9 and the freezing space 20 and returns past the throttling device 2| to'the'compressor ll. When the temperatures in the food preserving space and the ice freezing space have reached a sufficiently low temperature, the volatile fluid in the bulb 22 reduces the pressure in the bellows chamber 23 (see Fig. 6) of the throttling device and this causes the valve 2| to throttle the evaporated refrigerant returning from the evaporator iii to the compressor ll. When temperatures in these spaces rises, such as by the introduction of water to be frozen in the space 20 or of warm food in space IS, the bulb 22 responds and opens the throttling valve partly or wholly to increase the refrigerating capacity of the evaporator. The relative areas of the evaporator l3 and the heat 2 amass-s exchange facilities between this evaporator and the two spaces is so arranged that under normal conditions the proper temperatures will be maintained in both spaces in response to actuations of the volatile fluid in the bulb 22. In the modification shown in Fig. 3, the cabinet 33 is provided with a food preserving space 3| and a freezing space 32. A continuously operating compressor 33, driven by the constant speed motor 33a, supplies refrigerant to a condenser 34 from whence the refrigerant flows through the line 35 to the exchanger 33 and from thence, in parallel flow paths. through the evaporators or branches 31 and 33, the evaporated refrigerantreturning through the lines or paths 33 and 43 respectively to the main suction line 4| and from thence back to the compressor 33 in a closed cycle. The evaporated refrigerant returning to the compressor from one of the evaporators,

J in this case the evaporator 31, is throttled by the throttling valve 42, similar to the valve 2|, which valve 42 is made responsive in its throttling action to the temperature in the space 31 by means of the thermostatic bulb 43. The

5 valve 42 and bulb 43 may also be substantially of the character shown in Fig. 6.

The operation of the apparatus shown in Fig. 3'

is such that proper food preserving temperatures (above 32 F. and below 50 F.) are maintained in the space 3| by the throttling action of the valve 42, notwithstanding the continuous operation of the compressor 33', while the temperatures in the freezing space 32 are allowed to assume whatever temperature the refrigerating system is capable of maintaining therein; but the capacity of the refrigerating system is so made that it is sufficient to maintain temperatures in the space 32 below 32 F. If desired the freezing space 32 may be insulated from the food preserving space 0 3| by means of the insulated wall 43.

In the modification shown in Fig. 4, which is somewhat similar to that shown in Fig. 3, the compressor and condenser are substantially the same as shown in Fig. 3, the condensed liquid refrigerant flowing through the line 33 to the exchanger 5| and from thence, in parallel flow paths, to the evaporators or parallel branches 32 and 53. The evaporated refrigerant returns by means of the suction lines 34 and 35 respectively, through the interchanger 5| and back to the compressor (not shown, but similar to the compressor of Fig. 3) to close the cycle. In this modification, the return branch 55 from the evaporator 33 is also provided with a throttling valve 56, which m is similar in its action to the throttling valves heretofore described, but, in this case, the throttling action is made responsive to the temperatures in the freezing space 51. In this modification, like in the modification shown in Fig. 3, the evaporated refrigerant leaving from the evaporator 52 is throttled by means of the valve 58 responsive to the temperatures in the food preserving compartment 53 through the medium of the thermostatic bulb 30.

B5 In the modification shown in Fig. 2, the cabinet includes a brine tank 'il in which one or more ice cream can sleeves 12 are placed so that ice cream cans may be introduced by the removal of the lids 13. The brine in the tank II is cooled 70 by means of evaporator 14 which is part of the refrigerating system including the continuously operating compressor 15 and condenser 13. As is the case with the modification shown in Figs. 1,

3 and 4, the compressor I5 may be driven by the constant speed electric motor 11 which may be actuated by direct or alternating current in the well known manner. In this case. the evaporated refrigerant returning from the evaporator 14 to the compressor 13 is throttled by means of a valve i8 responsive to the temperatures of the brine 6 through the medium of the thermostatic bulb 13,. As is the case with all of the throttling valves heretofore described and shown in Figs. 1, 3 and 4, the valve 13 is made substantially as shown in Fig. 8. 10

The evaporators shown in Figs. 2, 3 and 4, may be of the well known flooded type having a float controlled inlet valve, the float maintaining a substantially constant level of refrigerant within the evaporator. To this end these evaporators 15 may be provided with a header 33, see Fig. 5, which contain the inlet valve 3| and the float control therefor 32. The liquid refrigerant is fed to downwardly directed heat exchangers 33,

which may be circular or plate-like ducts into which the liquid refrigerant flows and from which the evaporated refrigerant rises. The evaporated refrigerant leaves through the funnel 34 and returns to the compressor as heretofore described.

The throttling valves heretofore described may 23 be similar to that shown in Fig. 6. In this instance the line returning from the evaporator enters at 33 and leaves through the line 33 to the compressor. A throttling valve 24 is connected to the rod 33a which is sealed against the escape of refrigerant by the bellows 31. The thermostatic bulb 33 creates pressures in the chamber 23 which, acting on the bellows 33 varies the throttling action of the valve 24 in accordance I with the temperatures acting on the bulb 33. The so responsiveness of the valve to the cabinet temperatures aflecting the bulb 83 may be varied, so that the system may be caused to maintain different temperatures in the compartment wherein the bulb 33 is placed. To this end the spring 33 abuts against the adjustable screw 3| having a pointer handle 32. By returning the handle 32, with which a numbered temperature indicator dial, not shown, may be associated, the tension of the spring 33 may be varied, and this varies the responsiveness of the valve to the temperatures affecting the bulb 33.

A manually operated switch may be provided for stopping the compressor for repairs, or, very infrequently, for defrosting. This switch need not be operated to maintain cabinet temperatures during the period of refrigeration demand.

The throttling action of the valves heretofore described reduces the load on the compressor, so that, when the valves are nearly closed, the compressor practically idles and consumes practically no power. By eliminating the stopping and starting problems usual with a thermostatic switch, efficiency is enhanced and cost of production is reduced. 00

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. 5

What is claimed is as follows:

1. The method of refrigeration of a cabinet or the like by means of a system having a compressor, condenser and evaporator in a closed cycle, which comprises operating the compressor continuously during the entire period of refrigeration requirement of said cabinet, throttling the return of evaporated refrigerant from said evaporator to said compressor in accordance with cabinet temperatures and cooling condensed refrigerant before entrance in said evaporator by means of evaporated refrigerant after it has been throttled.

2. A refrigerating apparatus comprising a cabinet or the like, a refrigerating system for refrigerating said cabinet including a compressor, condenser and evaporator in a closed cycle, said compressor operating continuously during the en'- tire period of refrigeration requirement of said cabinet, means for throttling the return of evaporated refrigerant from said evaporator to said compressor in accordance with cabinet temperatures, and means for cooling condensed refrigerant before entrance into said evaporator by evaporated refrigerant after it has been throttled.

,3'. A refrigerating apparatus comprising a cabinet having a freezing space and a food preserving space, a refrigerating system for refrigerating said cabinet including a compressor, condenser and two evaporators in which the refrigerant flows in a closed cycle and in which said evaporators form parallel paths in said cycle between said condenserrand compressor, said compressor operating continuously during the entire period of refrigeration demand of said cabinet, one of said evaporators cooling said freezing space and the other of said evaporators cooling said food preserving space, means for throttling the return of evaporated refrigerant from one of said evaporators to said compressor in accordance .with temperatures in one of said spaces, and

means for cooling condensed refrigerant before entrance into one of said evaporators by means of evaporated refrigerant after it has been throttled.

4. The method of refrigeration of a cabinet having a freezing space to be maintained below 32 F. and a food preserving space to be maintained above 32 F. by means of a system having a compressor, condenser and evaporators in a closed cycle and said freezing space being an insulated space within said food preserving space, which method comprises operating the compressor continuously during the entire period of refrigeration requirement of said cabinet, cooling said freezing space and said food preserving space by means of said evaporators by operating them at difierent intensities, and throttling the return of evaporated refrigerant from one of said evaporators to said compressor in accord-.

ance with temperatures in said freezing space and food preserving space.

5. The method of refrigeration of a cabinet having a freezing space to be maintained below 32 F. and a food preserving space to be maintained above 32 F. by means of a system having acompressor, condenser and two evaporators in which the refrigerant flows in a closed cycle and in which said evaporators form parallel paths in said cycle between said condenser and compressor and said freezing space being an insulated space within said food preserving space, which method comprises operating the compressor continuously during the entire period of refrigeration requirement of said cabinet, cooling said freezing space by means of one evaporator and cooling said food preserving space by the other of said evaporators.

6. The method of refrigeration of a cabinet having a freezing space to be maintained below 32 F. and a food preserving space to be maintained above 32 F. by means of a. system having a single compressor, condenser and two evaporatorsin which the refrigerant flows in a closed cycle and in which said evaporators form paralinsulatedspace within said-food preserving space,

which method comprises, operating the compressor continuously during the entire period of refrigeration' requirement of said cabinet, cooling said freezing space by means of one evaporator and cooling said food preserving space by the other of said evaporators, and throttling the return of evaporated refrigerant from one of said evaporators.

7. The method of refrigeration of a cabinet having a freezing space to be maintained below 32 F. and a food preserving space to be maintained above 32 F. by means of a system having a single compressor, condenser and two evaporators in which the refrigerant flows in a closed cycle and in which said evaporators form parallel paths in said cycle between said condenser and compressor and said freezing space being an insulatedspace within said food preserving space, which method comprises operating the compressor continuously during the entire period of refrigeration requirement of said cabinet, cooling said freezing space by means of one evaporator and cooling said food preserving space by the other of said evaporators, and throttling the return of evaporated refrigerant from each of said evaporators.

8. The method of refrigeration of a cabinet having a freezing space to be maintained below 32 F. and a food preserving space to be maintained above 32 F. by means of a system having a compressor, condenser and evaporator in a closed cycle and said freezing space being an insulated space within said food preserving space, which method comprises operating the compressor continuously during the entire period of refrigeration requirement of said cabinet, cooling said freezing space to a temperature below 32 F. and said food preserving space to a temperature above 32 F. by means of said evaporator,and throttling the return of evaporated refrigerant from said evaporator to said compressor in accordance with temperatures in said I freezing space and food preserving space.

ferent temperaturesv by means of said evaporators,

and throttling the return of'evaporated refrigerant from said evaporators to said compressor in accordance with temperatures in said compartments.

10. The method of refrigerating separate spaces by means of a refrigerating system having a compressor-condenser unit and a plurality of evaporators connected in closed circuit relation which comprises, operating the compressorcondenser unit continuously during the entire period of refrigeration requirement of the spaces, cooling one space by means of one of said plurality of evaporators and cooling the other space by means of another of said plurality of evaporators, and throttling the return of evaporated refrigerant from said one evaporator to said compressor-condenser unit in accordance with the temperature of one of said spaces while permitting unrestricted return of evaporated refrigerant from said another evaporator to 'said compressor-condenser unit to operate the evaporators at different intensities relative to one another.

11. The method of refrigerating separate spaces by means of a refrigerating system having a compressorcondenser unit and a plurality of evaporators connected in closed circuit relation which comprises, operating the compressorcondenser unit continuously during the entire period of refrigeration requirement of the spaces, cooling one space by means of one of said plurality of evaporators and cooling the other space by means of another of said plurality of evaporators, throttling the return of evaporated refrigerant from said one evaporator to said compressor-condenser unit in accordance with the temperature of one of said spaces while permitting unrestricted return of evaporated refrigerant from said another evaporator to said compressor-condenser unit to operate the evaporators at different intensities relative to one another, and transferring heat from refrigerant supplied to said evaporators to the refrigerant returning to said compressor-condenser unit.

12. The method of refrigerating separate spaces by means of a refrigerating system having a compressor-condenser unit and a plurality of evaporators connected in closed circuit relation which comprises, operating the compressorcondenser unit continuously during the entire period of refrigeration requirement of the spaces, cooling one space by means of one of said plurality of evaporators and cooling the other space by means of another of said plurality of ture of the space cooled thereby to operate the evaporators at diflerent intensities relative to one another.

13. The method of refrigerating separate spaces by means of a refrigerating system having a compressor-condenser unit and a plurality of evaporators connected in closed circuit relation which comprises, operating the compressorcondenser unit continuously during the entire period of refrigeration requirement of the spaces, cooling one space by means of one of said plurality of evaporators and cooling the other space by means of another of said plurality of evaporators, throttling the return of evaporated refrigerant from said one evaporator to said compressor-condenser unit in accordance with the temperature of the space cooled thereby, throttling the return of evaporated refrigerant from said another evaporator to said compressorcondenser unit in accordance with the tempera ture of the space cooled thereby to operate the evaporators at different intensities relative to one another, and transferring heat from refrigerant supplied to said evaporators to the refrigerant returning to said compressor-condenser unit.

SYLVES'IER M. SCHWELLER.

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