US2533600A - Refrigerant control system - Google Patents

Description

Dec. 12, 1950 H. J. MATTESON REFRIGERANT CONTROL SYSTEM Original Filed April 29, 1941 C'ONDENS/NG I II ffaeom [114 77550,

INVENTOR.

Patented Dec. 12, 1950 2,533,600 REFRIGEBANT CONTROL SYSTEM Harold J. Mattcson, Glendale, Calii'., assignor to General Controls 00., Glendale, Calii'., a corporation of California Original application April 29, 1941, Serial No.

390,914, now PatentNo. 2,363,010, dated November 21, 1944. Divided and this application September 13, 1944, Serial No. 553,883

1 This invention relates to improvements in refrigerant-control valves of the thermal expansion type; the present application being a division of my copending application, Serial No. 390,914, filed April 29, 1941; now Patent No. 2,363,010, issued November 21, 1944.

When a valve of the type indicated is installed in a refrigerating system, on account of the nonlinear pressure-temperature curve of conventional refrigerants, the valve must be manually adjusted for the particular. average cooling temperature desired in the system. This necessitates the constant attention of an experienced service man, over a period of possibly several hours, until the system is stabilized. It is therefore a main object of this invention to overcome this difficulty by providing a valve whereby the superheat of the refrigerant at the outlet of an evaporator fed by the valve is automatically maintained substantially constant over a wide range of operating temperatures.

Another object is to provide a valve of the type indicated which, in the control of a refrigerating system, requires no manual adjustment over a wide range of operating temperatures.

Another object is the provision of a refrigerant control valve of the type indicated whereby, upon initiation of operation of the system, a high degree of super-heat is provided so that overloading of the system is prevented.

Another object is the provision, in a valve of the type indicated, of additional temperature responsive means for varying the effect of the temperature responsive means normally controlling the operation of the valve.

Another object is the provision of thermostatically controlled means for varying the force normally urging the valve closure member toward closed position.

Other objects and advantages of the invention will be found in the description, the drawing, and the claims; and, for full understanding of the invention, reference is to be had to the following detailed description and accompanying drawing, wherein:

Figure 1' is a longitudinal sectional view of a valve embodying the invention and shown schematically, connected in a conventional refrigeration system; and

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

In the drawing, the numeral 5| indicates a valve casing having an inlet 52 and an outlet 53 separated by a partition 54. Threaded in an opening in the partition is a member 55 having .4 Claims. (Cl. 62-127) a port opening 56 therethrough which interconnects said inlet and outlet. Cooperable with a seat formed at the lower end of the port opening, to control refrigerant flow through the valve in the direction indicated by the arrows, isa ballshaped'closure member 51 which is urged toward closed position by a compression spring 58, the upper end of the spring carrying a disk .59 pro vided with a central depression for receiving the ball 51, the lower end of the spring bearing against an internal shoulder formed in a hollow extension 60 threaded in the inlet of the valve casing. Within the extension 60 is a strainer ll' attached to,a fitting 42. Provided for the actuation of the closure member is a rod 6|, the bottom end of "which abuts the ball 51. The rod extends freely through the port 56 and its upper end portion is guided in a bore formed in the reduced upper end portion 6-2 of the port member 55, lateral openings 63 being provided in that portion of the port member for fluid communication between the port and the outlet 53.

For operating the valve there is a fluid pressure motor which comprises a flexible metallic diaphragm 64 secured, above a recess 65 formed in the upper end portion of the casing, by a cover 66; a thermal bulb 61 being connected by a pipe 68 to an opening formed in the center of the cover. The thermal bulb is preferably charged with a volatile fluid, the pressure of which is applied to the chamber defined by the diaphragm and the underside of the cover so that with increase of bulb temperature the diaphragm is forced downwardly. Below the diaphragm is a pusher plate 69 which has on its underside an integrally formed cylindrical extension 10 which extends through and is guided in'an opening in a wall II which separates the chamber or recess 65 from the outlet 53. Also formed in the wall II is an equalizer port 12.

Interposed between the adjacent ends of rod GI and pusher-plate extension 10 is one end portion of a bimetallic member 13 formed of relatively heavy strip material. The other end portion of the bimetallic member is wound in the form of a spiral and is held at its extremity by the bifurcated portion of a rod 14. This rod is mounted by its ends in the side walls of a hollow extension member 15 secured to the side 01' the casing and in communication with the outlet thereof. As is seen in Fig. 2, one end of rod 14 extends through the wall of member and is provided with a squared portion 16 whereby the rod may be turned to adjust the tension of the bimetallic member, the rod after adjust- 3 ment being secured in position by solder TI. The bimetallic member 13 is so constructed and arranged that, upon rise of temperature, the force, exerted by it on member ID in an upward direction, is increased.

In use in a refrigerating system, the outlet of the valve is connected to the inlet of the evaporator 18, so that the temperature of the refrigerant wherein bimetallic member 13 is immersed is substantially the same as that at the inlet of the evaporator. The thermal bulb 61 is made responsive to the temperature at the outlet of the evaporator 18 so that the valve is operated generally in a conventional manner. However, due to the varying bias produced by the bimetallic member in accordance with variation of temperature at the inlet of the evaporator, the operation of the valve is so modified that substantially constant superheat of the refrigerant is automatically maintained. It is to be noted that if the ball 51, the rod GI and the adjoining portion of bimetallic member 13 were mechanically united, it would be possible to dispense with the bias spring 58.

The embodiment of the invention herein shown and described is obviously susceptible of modification without departing from the spirit of the invention, and I intend therefore to be limited only by the scope of the appended claims.

I claim as my invention:

1. In a refrigerant control system: the combination with an evaporator of a thermostatically controlled expansion valve for controlling pas.- sage of refrigerant to said evaporator; said valve comprising: a casing having an inlet chamber, and an outlet chamber for connection to the inlet of said evaporator; a partition separating said chambers and having a valve port therethrough; a closure member cooperable with said port for controlling passage of refrigerant through the valve; a fluid pressure motor for operating said closure member in accordance with the temperature at the outlet of said evaporator; and a bimetallic member in said outlet chamber, and responsive to the temperature of the refrigerant therein, for modifying the action of said motor.

2. In a refrigerant control system: the combination with an evaporator of a thermostatically controlled expansion valve for controlling passage of refrigerant to said evaporator; said valve comprising: a casing having an inlet chamber, and an outlet chamber for connection to the inlet of said evaporator; a partition separating said chambers and having a valve port therethrough; a closure member cooperable with said port for controlling passage of refrigerant through the valve; means, adapted to respond to the temperature at the outlet of said evaporator, comprising a fluid pressure motor urging said closure member toward open position; resilient means urging the closure member toward closed position; and means, comprising a bimetallic memher mounted in said outlet chamber and responsive to the temperature of the refrigerant therein, for varying the resultant of the opposing forces produced by said urging means; variation of the forces produced by the individual tem perature-responsive means, due to temperature variations in the same sense, being in opposition.

3. In a refrigerant control system: the combination with an evaporator of a thermostatically controlled expansion .valve for controlling passage of refrigerant to said evaporator; said valve comprising? a casing having an inlet chamber, and an outlet chamber for connection to the inlet of said evaporator; a partition separating said chambers and having a valve port therethrough; a closure member cooperable with said port for controlling passage of refrigerant through the valve; a fluid pressure motor for operating said closure member in accordance with the temperature at the outlet of said evaporator; and an elongated bimetallic member mounted by one of its ends in said outlet chamber \and responsive to the temperature of the refrigerant therein, the other end portion of the bimetallic member being interposed betweensaid motor and said closure member.

4. In a refrigerant control system: the combination with an evaporator of a thermostatically controlled expansion valve for controlling passage of refrigerant to said evaporator; said valve comprising: a casing having an inlet chamber, and an outlet chamber for connection to the inlet of said evaporator; a partition separating said chambers and having a valve port therethrough; a closure member cooperable with said port for controlling passage of refrigerant through the valve: means, adapted to respond to the temperature at the outlet of said evaporator, comprising a fluid pressure motor urging said closure member toward open position; resilient means urging the closure member toward closed position; and means comprising an elongated bimetallic member mounted by one of its ends in said outlet chamber and responsive to the temperature of the refrigerant therein, the other end portion of the bimetallic member being interposed between said motor and said closure member; variation of the forces produced by the individual temperature-responsive means, due to temperature variations in the same sense, being in opposition.

HAROLD J. MATTESON.

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

UNITED STATES PATENTS Fonseca Oct. 23, 1934

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