US2068131A - Refrigerating apparatus - Google Patents

Description

Jan. 19, 1937. c. F. HENNEY 2,068,131

REFRIGERATING APPARATUS Filed Oct. 19, 1954 2 Sheets-Sh'eetil ATTORNEYS Jan. 19, 1937. c. F. HENNEY REFRIGERATING APPARATUS 2 Sheets-Sheet 2 I 1 17 0 Lt:

Filed Oct. 19, 1934 q a E M r a 163 7 164 Z Z NVENTOR.

TTORNEYS Patented Jan. 19, 1937 Charles F. Henney, Dayton, Ohio, assignor to General Motors Corporation, Dayton, Ohio, a

corporation of Delaware 3 Application October 19, 1934, Serlal'No. 749,017 1 10 Claims.

This invention relates to refrigerating apparatus and more particularly to that type of apparatus in which at least twoevaporators are maintained at different temperatures, or are so operated as to produce different temperatures in refrigerated spaces.

An object of this invention is to provide a refrigerating apparatus of the character above de- I scribed in which operating efllciency is increased. It is another object of my invention to provide an improved simple thermostatic control for a multiple refrigerating system operating at a. plurality of pressures.

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: V

Fig. 1 is a vertical cross-sectional view, somewhat diagrammatic of'an apparatus embodying features of this invention; I

Fig. 2 is a vertical cross-sectional view, somewhat diagrammatic of a modified form of the invention;

Fig. 3 is a horizontal cross-sectional view of the apparatus shown in Fig. 2; and

Fig. 4 is a diagrammatic illustration of a modified form of the invention.

In an apparatus wherein two evaporators have been connected to a single refrigerant liquefying unit, it has been customary to provide means whereby different temperatures may be obtained 4 from the diflerent evaporators. Howeverfithas been generally necessary to operate the refrigerant liquefying unit in such a manner that sub- V stantially all of the liquefying operation has been carried on with a very low back pressure, such back pressure usually corresponding to the pres- 0 sure prevailing'in the lowest'temperature evaporator. According to this invention, however, it is possible to operate the high temperature'evaporator or evaporators at back pressures corre-- sponding to their temperatures and to operate at ,5 low back pressure only when refrigeration is required in the low pressure evaporator or evaporators.

In the apparatus shown in Fig.1, as a specific embodiment, a soda fountain is provided with re- 5 frigerating means. The soda fountain, as here shown, includes a cabinet having insulated outer side, bottom and top walls and containing a for cooling drinking water, carcompartment l0 bonated water and the like; a compartment Ii for cooling bottled brinks and the like and a compartment I2 for cooling ice cream and other foods requiring relatively low temperatures. Also an insulated syrup rail or compartment, diagrammatically indicated at i 3, is generally provided above the main part of the cabinet in which is keptthe various syrups and flavors. Under ordinary circumstances, it is generally desired to maintain the compartment ill at ap proximately 34 F., the compartment. Ii at approximately F., the compartment I2 at temperatures ranging from approximately 0 F. to v 10 F., while the compartment I3 is generally maintained at approximately 50 F.

Sometimesthecompartment I2 is within itself provided with different temperatures, and, in this instance, it may be accomplished by providing a partition l4 so that the brine on the left side may be maintained at 0 F. while the brine on the right hand side may be maintained at approximately 7 F.

, Inorder to refrigerate the soda fountain, a refrigerant lii uefying unit 20 is provided which is connectedby means of a liquid refrigerant line 2| with the evaporators hereinafter to be described and by the evaporated refrigerant line 22 which receives the refrigerant evaporated in the evaporators and returns the same to-the unit 20. The unit 2|! may be. of the compressor-condenser type, if desired, and thus includes a com-' pressor 23,a condenser 24, receiver 25, the latter beingconnected to the liquid refrigerant line 2|.

The compressor is operated -by a motor 26 which is started and stopped by means of a snap switch 21 operated by the bellows 28 in a manner hereinafter to be more fully described.

- The soda fountain is provided with a plurality of evaporators; and'thus includes a high pressure evaporator 30, partly in the compartment l0 and partly in the compartment", and a low .pressure evaporator 3| partly in the compartment i3 and partly in the compartment I2. An expansion valve 32 connects the line 2| with the evaporator 30 and an expansion valve 33 0onnects the evaporator 3| with the line 2|. These valves are automatically controlled and are so arranged. as to prevent flow of refrigerant into the evaporators at predetermined high pressure limits respectively 'and automatically open when the pressures in the evaporators drop below said predetermined limits. Thus the valve 32 automatically opens when the pressure within the evaporator 30. falls. to a pressure corresponding to 34 F. whichwith S02 is approximately 9 pounds. The valve 33 automatically opens ata pressurecorre high temperature, for instance 34 F. The bulb- 35 may thus be soldered to the pipe forming part of the evaporator 30 at the pointshown immediately above the level 38 of the liquid in the compartment, so that the bulb is not cooled to the predetermined temperature until the liquid in compartment l reaches that temperature.

The compartment I0 is filled with water or some liquid of similar freezing temperature and one or more coils 31 are placed in the compartment I0 through which drinkingwater, carbonated water and the like flows and is cooled by the liquid in the compartment III which liquid in turn is cooled by the submerged coils 33a of the evaporator 30.

The evaporator 30 continues in the form of a pipe 30b through the syrup rail II to a second valve 39. This valvepreferably is of the snap acting type and is adapted to snap shut when the pressure in the evaporator 33 falls below a predetermined pressure, said pressure being below the pressure at which the valve 32 opens when not closed by the thermostatic control 34. The snap acting mechanism of the valve- 39 is made responsive to the pressure within the evaporator 30, for instance for diagrammatic showing, through the tube 40. A type of valve suitable for valve 39 is disclosed in the application of Gilbert H. Williams, Serial No. 351,363, flied March 30, 1929. The valve 33 is set to open and close at pressures which with 80: would be -12 pounds a and 0 pound respectively. The evaporator 3| has a valve 33 similar to the valve 32, also provided with a thermostatic device 4|, although this thermostatic device may, if desired, be omitted with the type 'of motor control shown in Figs. 1 to 3 inclusive. The thermostatic'device 4| includes a bulb 42 connected to the outlet end of the pipe which terminates the evaporator 3| and is connected to the valve 33 to close the same when the bulb 42 reaches a. predetermined low temperature. 'I'he evaporator 3| is also pro- 1 vided with a check valve 43 connecting the low pressure evaporator 3| with the evaporated refrigerant line 22. I ranged that it permits flow of the refrigerant from the evaporator 3| to the line 22 but prevents the flow from the line 22 to the evaporator 3 I.

Provisions for causing the refrigerant liquefying unit to operate in accordance with certain conditions-in the evaporators is provided. Preferably the unit 20 is controlled by condensation, before return to the unit, oi refrigerant evaporated in the high pressure evaporator 33. Thus a heat exchanging device 44 is constructed in the form of a downwardly directed loop Li a pipe from the valve 33. Thisloop is in heat exchange relation to the evaporator 3|. responsive to the device 443 is provided for con trolling the operation of the refrigerant liquefying unit 20 and this includes a thermostatic bulb 45 adjacent the loop 44, the bulb 45 being con-'- nected by means of the pipe 38 with the bellows which operates the snap switch 21 which con- The check valve 43 is so ar- 4 Control means.

. change device 44 and is there condensed by reason of the cold temperature of evaporator 3|. The

'heat of condensation of the refrigerant in loop 44 warms the bulb 45 and causes it to close the switch 21 and start the motor 26.

If the liquid in the compartment in requires refrigeration, the compressor begins evaporating refrigerant in the evaporator 30 and operates at a back pressure equal to-the pressure at which the valve 32 is set to open. Refrigeration continues at this back pressure until such a time as the coil 30a adjacent the bulb 35 is cooled sufficiently to close the valve 32 by the action of the bulb 35. When the valve 32 is closed the compressor quickly pulls the pressure of the evaporator 30 down to such a pressure that it will cause the valve 39 to snap shut. When this happens the compressor 23 quickly pulls down the pressure in the line 22 to the point where valve 33 is opened permitting refrigerant to flow through the evaporator 3|. The compressor then continues to run until such a time as the brine in the compartment I2 is cooled suiliciently to cause the bulb 45 to open the switch 21 and stop the compressor 23. In this system the compressor perthe syrup rail before passing the pipe comprising the evaporator 3| in the form of coils 3": and 3|c around the sleeves in'the compartment l 2.

The compartment l2 in this particular embodiment includes a brine tank and a plurality of sleeves 5|, l2 and 53. The refrigerant after passing through the coils 3 la passes through the coil 3 lb surrounding the sleeve SI and from thence as indicated through the coil 3| 0 surrounding the sleeves 52 and 53 past the check valve 43 into the evaporated refrigerant line 22.

Figs. 2 and 3 show substantially the same system shown in Fig. 1 applied to a cabinet in which the ice cream sleeves are embedded in concrete. The corresponding parts of the refrigeratingisystem'are similarly numbered in these figures, with the exception that 100 has been added to the numbers. Thus the liquid refrigerant line |2| in Fig. 2 corresponds to .the liquid refrigerant line 2| in Fig. l, the same being true with respect to all other corresponding numbers.

In the modification shown in Figs.) and 3 the sleeve Iii, instead of being submerged in a brine tank, is encased in a concrete casing I30. A larg substantially square sleeve I52, I33 is encased in a concrete casing I9| and is provided with a control metal plate to divide it into sub-compartments and to provide for conduction of heat. The casings I60 and |3| are placed around the sleeves after the coils lb and |3|c have been placed around the sleeves l5l, |32--|53 respectively. The concrete is preferably quick drying Portland cement used without any sand or other ingredients except water. If desired, the coils |3 lb and I3 lc may be made of copper tubing with fins attached thereto. The fins if desired may be a continuous spiral strip wound around the pipe. Thecement is dried after it has set.

The loop 144 together with the bulb in is placed 15 immediately outside the sleeve and is also embedded in the concrete sleeve I60.

The-casings I60 and I6I rest on the cork board bottom I63 and are spaced from each other by a slab'or cork I64. A'second slab of cork I65 is placed on the other side of the casing I60 after which loose ground cork I66 is poured between the slabs of cork and the casings I60 and NH. Inthese modifications the compressing unit preferably is identical with that shown in Fig. 1.

This system provides a simple thermostatic control having only one thermostat bulb and switch mechanism for controlling the operation of the motor-compressor unit, not only when the compartments I2 and H2 in the two modifications respectively, require refrigeration, but also when the valves 39 and I39 open to discharge gas from the evaporators 30 and I30 which are emerged in the compartments I0 and H0 respectively. This provides a control which is substantially equal in performance to others requiring one or more additional thermostats, and in particular this system provides a very accurate control for the temperatures in the ice cream compartments and a reasonably accurate control of the temperature in the beverage cooling compartment,/all with the control of the motor-compressor unit by a single thermostat bulb and switch.

Fig. 4 shows how either of the modifications shown in Fig.1 or in Figs. 2 and 3 may be provided with a slightly different motor control. Thus the refrigerant liquefying unit 220 may correspond to the motor 26, compressor 23, condenser 20 and liquid refrigerant receiver 25 shown in Fig. l. The refrigerant circuits shown diagrammatically in Fig. 4 corresponds in number with those shown in Fig. 1 with the exception that 200 has been added to the numbers. In addition, an extra loop 210 is added after the bulb M of Fig. 1, the loop 270 being carried in the syrup rail 2I3 to act as a "drier for the evaporated refrigerant after passing the bulb 242. The coils are placed in positions corresponding to those shown in Fig. 1, it being understood that sleeves are placed within some of the coils and that another coil is submerged in liquid corresponding to compartment I0. The details of the cabinet have been omitted in Fig. 4 in order to show more clearly the refrigerating system.

The systemshown in Fig. 4, is further modified with respect to the system shown in Fig. 1 by providing a "low pressure" control for the refrigerant liquefying unit 220. Thus the loop 44 and bulb 45 have been omitted in Fig. 4 and in lieu thereof the bulb 228 is actuated by the pressure in the evaporated refrigerant line 222, the bulb 220 merely being connected by a pipe 2' with the line 222, to be responsive to the pressure in the low side of the system.

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.

The several organizations disclosed in this case are disclosed in applicant's earlier Patent No. 1,985,252. The claims of this application, however, all difier from the claims of the patent by including the control meansv and its relation to the rest of the organization.

What is claimed is as follows:

1. A refrigerating system including a refrigerant liquefying unit, a plurality of evaporating means, supply and return conduits connecting the evaporating means with the liquefying unit,

one of said evaporating means and with a portion of the return conduit of another of the evaporating means for controlling the operation of said liquefying means.

2. A refrigerating system including a refrigerant liquefying unit, a plurality of evaporating means, supply and return conduits connecting the evaporating means with the liquefying unit, means for maintaining said evaporating means at a plurality of pressures, a portion of the return conduit of one of the evaporating means being in heat exchange relation with another of the evaporating means, and thermostatic means in heat exchange relation with said portion of the return conduit for controlling the supplying of liquid refrigerant to the evaporating means.

3. A refrigerating system including a refrigerant liquefying unit, a high pressure evaporator, a

low pressure evaporator, a liquid refrigerant line and an evaporated refrigerant line connecting said unit and said evaporators, an expansion valve for each of said evaporators connected to said liquid refrigerant line, a pressure responsive,

fore the return of said refrigerant to said liquefying unit.

4. A refrigerating system including a refrigerant liquefying unit, a high pressure evaporator, a low pressure evaporator, a liquid refrigerant line and an evaporated refrigerant line connecting said unit and said evaporators, an expansion valve for each of said evaporators connected to said liquid refrigerant line, a pressure responsive valve connecting said high pressure evaporator and said evaporated refrigerant line, and means for controlling said refrigerant liquefying unit according to condensation of refrigerant evaporated in said high pressure evaporator by the cooling action of said low pressure evaporator before return of said refrigerant to said liquefying unit.

5. A refrigerating system including a refrigerant liquefying unit, a high pressure evaporator, a low pressure evaporator, a liquid refrigerant line and an evaporated refrigerant line connecting said unit and said evaporators, an expansion valve for each of said evaporators connected to said liquid refrigerant line, the expansion valvefor said high pressure evaporator being automatically controlled for preventing flow of refrigerant in said high pressure evaporator at a predetermined pressure in said high pressure evaporator, a pressure responsive valve connecting saidhigh pressure evaporator and said evaporated refrigerant line, and means for controlling said refrigerant liquefying unit according to condensation of refrigerant evaporated in said high pressure evaporator before return of said refrigerant to said liquefying unit.-

6. A refrigerating system including a refrigerant liquefying unit, a high pressure evaporator, a low pressure evaporator, a liquid refrigerant line and an evaporated refrigerant line connecting said unit and said evaporators, an expansion valve for each of said evaporators connected to said liquidrefrigerant line, a pressure responsive valve connecting said high pressure evaporator I L from said high pressure evaporator bysaid low pressure evaporator, and control means responsive to said device for controlling the operation of said refrigerant liquefying unit.

7. A refrigerating system including a refrigerant. liquefying unit, a high pressure evaporator, a low pressure evaporator, a liquid refrigerant line and an evaporated refrigerant line connecting said unit and said evaporators; an expansion valve automatically responsive to open when the pressure on its discharge side is below a predetermined pressure, said valve connecting said high pressure evaporator and said liquid refrigerant line, a thermostatic control for closing said valve when a predetermined temperature has been reached in said high pressure evaporator, a second valve between said high pressure evaporator and said evaporated refrigerant line automatically closing when the pressure in said high pressure evaporator is below the opening pressure of said first named valve, an expansion valve connecting said low pressure evaporator and said liquid refrigerant line, a heat exchanging device for cooling evaporated refrigerant passing the second valve by said low pressure evaporator, and control means responsive to said device for controlling the operation of said refrigerant liquefying unit.

8. Refrigerating apparatus including refrigeraoeaisr ant liquefying and evaporating means, and means for condensing refrigerant between the outlet of said evaporating means and the inlet of said liquefying means, and means for controlling the liquefying means according to the refrigerant condensed by said condensing means.

9. Refrigerating apparatus including a closed refrigerant circuit containing a high pressure portion and a low pressure portion, said high pressure portion including a refrigerant 'liquefying means and said low pressure portion including a refrigerant evaporating means, means for condensing refrigerant in a part of said low pressure portion, and means for controlling the circulation of refrigerant according to refrigerant condensed by said condensing means.

10. Refrigerating apparatus including a closed refrigerant circuit containing a high pressure portion and a low pressure portion, said high pressure portion including a refrigerant liquefying means and said low pressure portion including a refrigerant evaporating means, means for condensing refrigerant in a part of said low pressure portion, and means for controlling the liquefying 7 means according to refrigerant condensed by the condensing means.

- CHARLES F. HENNEY.

Images