US2133960A - Refrigerating apparatus - Google Patents

Description

G; s. M CLOY REFRIGERATING APPARATUS Filed Dec. 16, 1936.

INVENTOR GRAHAM EMS C LOY BY 2% ATTORNEZ? Patented Oct. 25 1938 REFRIGEBATING APPARATUS Graham S. McCloy, East Longmeadow, Masa, assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa, a corporation of Pennsylvania Application December 16, 1936, Serial No 116,102

r 12 Claims.

My invention relates to refrigerating apparatus wherein the quantity of refrigerant available for circulation is varied and has for an objectto provide improved apparatus of this kind.

A further object of my invention is to provide improved means for varying the amount of refrigerant present in one or more evaporators.

A further object of the invention is to provide an improved unitary structure for varying the amount of refrigerant available for circulation in a refrigerating system and for controlling the admission of refrigerant to one or more evaporators.

While not so limited, my invention is particularly applicable to two-temperature refrigerating systems of the type disclosed and claimed in the copending application of Leslie B. M. Buchanan, Serial No. 15,003, filed'April 6, 1935, and assigned to Westinghouse Electric 8; Manufacturing Company. The embodiment of my invention dis closed hereinafter relates to a two-temperature system of the type shown in this application.

The foregoing and other objects are eifected by my invention as will be apparent from the following description and claims taken in connection with the accompanying drawing forminga part of this application, in which:

Fig. 1 diagrammatically shows a two-temperature refrigerating system constructed and arranged in accordance with my invention, certain portions of which are shown enlarged; and,

Fig. 2 is a section taken along the line 11-11 of Fig. 1.

Referring to the drawing, a two-temperature refrigerator structure is shown generally at it] and includes relatively low and high temperature zones or chambers H and 92, respectively. The chambers H and 52 are refrigerated by respective low and higher temperature evaporators l3 and i4. Refrigerant vaporized in the evaporators l3 and I4 is withdrawn through a conduit l5 by means of a compressor 16 driven by a.

motor H, which define elements of a condensing unit, generally indicated at l8. The condensing unit I8 includes a condenser 19 cooled in any suitable manner such as, for example, by a fan condensed refrigerant from the float valve structure 21 to the evaporators i3 and i4 and is preferably connected to the evaporator 13, as shown. Further reference to the admission of refrigerant to the evaporators will be made hereinafter.

The structure 24 will now be described in detail. The upper portion of the casing 25 which is preferably of cylindrical form, defines the reservoir 26 for storing refrigerant during certain periods of operation of the apparatus. The condensed refrigerant conveyed by the conduit 23 is discharged into the reservoir 26. 29 at the bottom of the casing 25 receives condensed refrigerant from the reservoir 26 through a conduit 32 or through a passage 33 under control of a valve 34. The conduit 32 includes a portion 35 fixed preferably in the wall 28 and a movable portion 35 that is adjustable vertically with respect to thefixed portion 35. Preferably, the conduit portion 36 is threaded on the fixed portion 35 and is rotatable with a stem 31 extending through the casing 25. The upper or movable conduit portion 36 is provided with one or more inlets 38 for the passage of refrigerant from the reservoir 26.

I As shown best in Fig. 2, the stem 31 is preferably of hexagonal formation where it engages the conduit portion 36, so that rotation of the stem 31'. effects rotation of the conduit portion 36. The conduit portion 36 is slidably mounted on the stem 31 so that movement thereof axially of the stem 31 is permitted. The stem 31 includes an upper circular portion 39 rotatably mounted within a fitting M that isvsecured to the casing 25. An end d2 of the stem 31 is suitably formed for engagemenVwith an adjusting tool or wrench whereby the stem 31 may berotated. Packin shown at 13 may be employed between the rounded portion 39 of the stem and the fitting 4| for preventing escape of refrigerant fromthe' casing 25. r A cap 44 is threaded on the fitting 4| for further preventing escape of refrigerant and is removable so that the end42 of the stem 31 is accessible for adjustment. I

The passage 33 is preferably formed in a cyline drical valve cage 45 secured in the wall 28. The valve cage includes inlet ports 46 for the passage of refrigerant/from the reservoir 26 when the valve 34 is raised and seat 41 is formed in the valve cage 45 for the valve member 34. Means is provided for actuating the valve 34 and preferably. includes a solenoid winding 48 arranged exteriorly of the casing 25 and a core 49 disposed within the casing and subjected to the field pro- The chamber duced by the winding 48. Energization of the 55 winding 49 effects upward movement of the core 49 and deenergization of the winding permits the core 49 to drop by gravity. The core 49 and valve 34 are secured together by a rod 5| so that the valve 34 is opened and closed as ;the core is raised ber pass through the casing with the possibility of gasleakage. The embodiment disclosed is. therefore, desirable in this respect.

The float valve structure 21 of which the chamber 29 is a part includes a valve member 52 that is actuated by a float 53. The valve 52 cooperates with a seat 54 preferably formed in an outlet member 55 that is fixed in the casing 25. As shown, the conduit 3| is secured to the outlet member 55. The valve 52 is moved in opening and closing directions as the level of the liquid refrigerant in the chamber 29 rises and falls, respectively.

It will be understood that the charge of refrigerant in the system is such that when the reservoir 26 is empty, the evaporator I3 is substantially filled with refrigerant, and liquid refrigerant occupies a portion of the evaporator l4. When-refrigerant is stored in the reservoir 26,

the evaporator l3 contains a substantial amount of liquid refrigerant and the evaporator i4 is dry. As shown, the liquid supply conduit 3| admits refrigerant to the evaporators l3 and I4 in such manner that refrigerant flows into the evaporator IS in preference to the evaporator [4. When the evaporator I3 is filled, overflow of refrigerant into the evaporator I4 is effected.

The amount of refrigerant present 'in the low temperature evaporator l3 during periods when it .is operated may be varied by varying the amount ofrefrigerant in the reservoir 26. By adjusting the movable conduit member 36 upwardly, more refrigerant is stored in the reservoir 26 and less is present in the evaporator l3. The total charge of refrigerant in the system is circulated during periods when the valve 34 is in its open position and fills the evaporator l3 and a .substantial portion of the evaporator l4.

Automatic control of the system may be effected by thermostats 56 and 51 disposed in the 48 and the motor I! is represented by the line conductors L1 and L1. The motor I1 is energized by the thermostat switch 58 whenclosed in response to a predetermined high temperature in the chamber II, the circuit for the motor I! including a conductor 6|. when the thermostatic switch 59 is closed, the motor I I is energized by acircuit including a conductor 62 and the sole-1 noid winding 49.

Operation The positions of the various elements of the system as shown in the drawing indicate that the temperatures in both chambers are below values at which their respective thermostatic switches close and, therefore, the motor l1 and compressor l6 are inactive. The reservoir 26 is empty which indicates that both evaporators l3 and I4 contain liquid refrigerant and that. the previous cycle of operation eifected refrigeration of the high temperature chamber l2.

Assume a rise in the low temperature chamber II to the value at which the thermostatic switch and thesolenoid winding 49 remains deenergized. Accordingly the valve 34 is in its closed position and operation of the compressor I6 is initiated. Refrigerant present in the evaporator I4 is vaporiz'ed and condensed in the condenser l9. The liquefied refrigerant is delivered for storage in the reservoir 26 until the level of the liquid rises to the overflow inlets 38 in the conduit 32. Some cooling of the high temperature evaporator I4 is effected at this time by the refrigerant vaporized therein but it is of short duration as the A refrigerant is soon vaporized.

The pressure ofthe refrigerant in the evaporator i3 is reduced by the compressor l6 and the vaporized refrigerant is'conveyed through the evaporator l4 to the condenser l9 by the compressor l6. The liquid refrigerant delivered to the reservoir '26 overflows through the conduit 58 is closed. The motor I! is energized thereby Operation of the compressor [6 progressively decreases the pressure and temperature of the refrigerant in the evaporator 13 to the value at which thermostatic switch 56 opens to terminate operation of the compressor l6.

Assume a rise in temperature in the chamber l2 to the value at which the thermostaticswitch 59 is closed. The motor I1 and the-solenoid 49 are energized by a circuit including the conductor 62. Accordingly, operation of the compressor l6 v is initiated and the valve 34 is raised from its seat 41. Refrigerant present in the reservoir 26 passes through the passage 33 to the chamber 29 and effects full opening of the valve 54. Refrigerant fills the evaporator l3 and overflows into the evaporator l4 and is rapidly vaporized due to the relatively high temperature thereof.

At this time the entire charge of refrigerant is available for circulation so that both evaporator l3 and f 4' contain liquid refrigerant. As the evaporator I3 is substantially filled with condensed refrigerant, a seal is. defined for preventing refrigerant vaporized in the high temperature evaporator l4 from condensing in the low temperature evaporator l3. vaporization in the low temperature evaporator I3 is not effected at this time as the temperature of the evaporator I3 is lower than the temperature of vaporization corresponding to the pressure of the contained refrigerant.

The compressor l6 operates to decrease the pressure and temperature of the refrigerant in the evaporator l4 until the thermostat 51 opens its switch 59 in response to a predetermined low temperature within the chamber l2,- atwhich time the compressor 16 is stopped and the valve ductor 6| defines a shunt across .the winding 48 when both thermostatic switches 58 "and 59 are closed, and, therefore, the winding 48 is deenergized and the valve 34 is in its closed position. Accordingly, refrigerant is stored in the reservoir 26 and condensed refrigerant is present for vaporization in the low temperature evaporator l3 only. It will be understood that preference may be given to the high temperature thermostat 57 if desired.

I have shown my improved system applied for refrigerating two zones of a refrigerator and including two evaporating elements but it is to be understood that it may be applied to single evaporator systems in which the amount of liquid refrigerant present in the low side thereof is to be varied.

From the foregoing, it will be apparent that I have provided an improved refrigerating system having means for withholding condensed refrigerant from circulation, wherein the amount of refrigerant withheld may be readily varied and wherein a compact unitary structure is provided.

for varying the quantity of refrigerant available forcirculation and for controlling its admission to the evaporator or evaporators. While I have shown'a refrigerating system of the compressorcondenser-expander cycle, it will be understood that my invention is applicable to other types of refrigerating systems;

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is notv so limited, but is susceptible of various changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art claims.

What I claim is: L In a two-temperature refrigerating system, the combination of a pair of evaporator elements,

or as are specifically set forth in the appended means forcondensing refrigerant vaporized in the evaporator elements, means for conveying the condensed refrigerant to the evaporator elements for vaporization and means for withholding a predetermined quantity of condensed refrigerant from circulation at certain times during the o eration of the system, whereby condensed refrig erant is delivered to only one of the 'evaporatoif elements at that time, said refrigerant withhold 7 ing means including an adjustment for varying the amount of refrigerant that may be withheld from said one evaporator element.

2. In a refrigerating system, the combination of an evaporator having first and second .por-i tions, means for condensing refrigerantvaporized in the evaporator, means for conveying the.

condensed refrigerant to the evaporator for vaporization and means for withholding a predetermined quantity of condensed refrigerant from circulation whereby the effective charge of the evaporator, means for conveying the con-- densed refrigerant to the evaporator for vaporization and means for withholding a predetermined quantity of condensed refrigerant from device for the condensed refrigerant disposed beneath the reservoir for receiving condensed refrigerant therefrom and an adjusting device for varying the storing capacity of the reservoir and extending exteriorly of thereservoir- 4. In refrigerating apparatus, the combination of an evaporator, means for condensing refrigerant vaporized in the evaporator, a casing defining a. reservoir forreceiving condensed refrigerant from the condensing means and an ex;

pansion device disposed at a lower level than the reservoir for controlling the admission of refrigerant to the evaporator, a conduit communicating with the reservoir and the expansion device, said .conduit having its inlet disposed at v variable elevations within the reservoir, means for adjusting the elevation of the conduit inlet,

',valve means controlling communication between the reservoir and the expansion device and opened .and closed for respectively releasing refrigerant from the reservoir and for storing the same therein, and means for actuating said valve. 5. The combination as claimed in claim 4 wherein the valve actuating means is disposed at least in part exteriorly of theeasing.

6-. The combination as claimed in claim ,4 wherein the valve actuating means is electrically operated.

. 7. Intwo temperature refrigerating apparatus,

the-combination of low and high temperature evaporators, means for condensing refrigerant vaporized in the evaporators and means for conveying the condensed refrigerant to the evaporators and comprising means for decreasing or increasing the effective charge of refrigerant whereby condensed refrigerant is supplied to the .low temperature evaporator only for. vaporization at low pressure or is supplied to both evaporators for vaporization primarily in the high temperature evaporator at relatively high pressure, said charge varying means including a reservoir for condensed refrigerant, an expansion device for receiving condensed refrigerant from the reservoir and for controlling its admission to the evaporators, a conduit providing communication between-an upper portion of the'reservoir and the expansion device.and having at least a portion thereof adjustable, means for adjusting said conduit portion upwardly and downwardly in thereservoir, means providing communication between a lower portion of the reser-'- voir'and the expansion device, a valve associated with the last-named means, and means for opening and closing said valve.

8. In a refrigerating system, the combination of first and second evaporators, means for condensing refrigerant vaporized in the evaporators,

a casing defining a reservoir and a float valve structure therebeneath, said float valve control- .ling the admission of refrigerant to the evaporator, means for conveying the condensed refrigerant to the reservoir, an overflow conduit communicating with an elevated portion of the an adjustable portion, means for adjusting the means defining a passage for providing communication between a bottom portion of the reservoir and the float valve structure, a valve controlling the passage, and means responsive to demands for refrigeration by the 'evaporators for opening and closing the valve, whereby as the valve is closed refrigerant is stored in thereservoir and condensed refrigerant is supplied to the first evaporator only and when the valve is open the stored refrigerant is released and substantially fills the first evaporator and at least a portion of the second evaporator.

9. In refrigerating apparatus, the combination of a unitary casing structure defining a float valve chamber and a reservoir thereabove, a conduit providing communication between the float valve chamber and an upper portion of the reservoir, said casing structure including a passage providing communication between a bottom portion of the reservoir and the fioat valvechamber, a valve controlling said passage, means for actuating the valve, means for admitting condensed refrigerant to the reservoir and means for conveying condensed refrigerant from the float chamber for vaporization.

10. -In refrigerating apparatus, the-combination of a unitary casing structure defining a float valve chamber and a reservoir thereabove, a conduit providing communication between the float valve chamber and an upper portion ofthe reservoir, means for adjusting said conduit upwardly and downwardly with respect to the reservoir, said casing structure including a passage providing communication between a bottom portion of the reservoir and the float valve chamber, a valve controlling said passage, means for actuating the valve, ineans for admitting condensed refrigerant to the reservoir and means for conveying condensed refrigerant from the float chamber for vaporization.

, 11. In refrigerating apparatus, the combination of an evaporator, means for condensing refrigerant vaporized in the evaporator, a casing defining a reservoir for receiving condensed refrigerant from the condensing means, means for conveying therefrigerant from said casing to the evaporator and including a conduit, said conduit having its inlet disposed at variable elevations within the reservoir, means for adjusting the elevation of the conduit inlet, valve means consaid structure having a conduit portion secured to the casing, and a rotatable conduit portion threaded to the fixed conduit portion and having an upper portion thereof in communication with the reservoir, a rotatable stem extending exteriorly of the casing and splined to the rotatableconduit portion, means defining a passage for providing communication between a bottom portion of the reservoir and said conveying means,

a valve controlling the passage and means for actuating said valve.

. GRAHAM S. McCLOY.

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