US1705764A - Refrigeration system - Google Patents

Description

March 19, 1929. s. HILGER REFRIGERATION SYSTEM Filed Dec. 24, 1925 Patented Mar. 19, 1929.

UNITED STATES GEORGE HILGEB, OF CHICAGO, ILLINOIS.

REFRIGERATION SYSTEM.

Application filed December 24, 1925. Serial No. 77,444.

The invention relates to a refrigeration system and has for its general object the provision of improved means for controlling the flow of refrigerant to the expansion coil or coils. I a

An especial object is to provide a regulating valve for use in refrigeration systems operatingin response to variations in the temperature of a room or chamber being refrigerated and which, while positive in operation, is extremely sensitive to temperature changes.

Still another object is to provide a regulating orcontrol valve in which the valve member is operated by a differential in pressure bet-ween two opposed pressure responsive elements, one of which is responsive to room temperature and the other of which is responsive to the pressure of the refrigerant flowing to the expansion coil, a condition of balance between the opposed forces obtaining at the desired room temperature;

A general object is to provide a control valve which is simple in construction and ex-.

ceptionally durable in character.

Figure 1 of the drawings is' a view partially diagrammatic in character illustrating a refrigeration system embodying my invention.

Fig. 2 is a vertical sectional view on an enlarged scale through the regulating valve.

The system is herein shown as applied-to two cooling rooms or chambers A an containing an expansion coil 3 having one end connected with a supply line 4 and the other end connected with a return line 5. Refrigerant is supplied to the supply line 4 in the operation of a suitable compressor 6. 7 is a condenser of ordinaryconstruction and 8 a liquid receiver. The supply of refrig erant to the line is under the control of an expansion valve'9 which-is preferably of the automatic constant pressure type.

Interposed in the connection between the supply line 4 and the expansion coil 3 of each of the chambers is a regulating valve generally designated by the numeral 10. This valve is arranged to be operated by a differential in pressure between the pressure of the refrigerant flowing to the coil 3, and

the pressure of a temperature responsive pressure device generally designated by the numeral 11.

The valve 10 (Fig. 2) comprises a casing 12 having a passageway therethrough controlled by a valve member 13. The casing has a transverse partition 14 therein constructed to provide a vertically disposed port 15 formed in a threaded member 16, the

latter providing a valve seatl? for the 'valve member herein in the form of a ball 13. The upper portion of the member 16 is con structed to provide a cage 18 loosely receiving the ball. The inlet port 19 opens into the valve casing'above the partition 14, and the outlet 20 leads from the valve casing from a point below the transverse partition 14 and diametrically opposite the inlet port 19. o

The valve member 13 is normally held to its seat 17 by a coiled expansion spring 21, acting at its lower end upon a flanged block 22 adapted to rest upon the ball, and at its upper end-upon a similarly flanged block 23 vertically adjustable by means of a screw 24. For receiving the spring 21, the screw 24 and associated parts, the valve casing has a bonnet 25 screw-threaded into the upper end of the casing and constructed to provide a chamber 26 for the spring and its pressure blocks 22 and 23. The screw 24 is threaded into the upper end of the bonnet as indicated at 27 and bears in a central recess 28 in the upper end of the block 23. The screw 24 has an operating stem 29 projecting through a suitable stufling box 30 and squared at its upper end 31 to receive a ring or the like.

The means for operating the valve member 13 to regulate the flow of refrigerant through the valve casing 12 is, as above indicated, under the controf of the temperature responsive device 11. To this end I provide a pressure responsive element or plate 32 operatively associated on the one hand with the valve member 13 and responsive on the other hand to the pressure device 11. This pressure plate 32 is enclosed within and normally rests upon the bottom of a chamber 33 connected with a hollow cylinder 35 by a pipe 34 opening into the bottom of the chamber. This 'cylinder is adapted to contain a charge of ammonia or other temperature responsive element and constitutes the pressure device 11.

The chamber 33 is in the lower end of the valve structure, and is formed by means of an annular casing 36 having a bottom wall 37 enclosed at its upper end by the bottom wall 38 of a hollow spacing member 39 which latter has a top wall 40 to. which is secured the lower end of the valve casing 12.

. adapted to move vertically. Said block 42 has a central pin 43 projecting upwardly 1 into the valve port 15 and adapted to engage with the valve member 13.

Pressure imparted to the plate 32 in the chamber 33 is transmitted to the valve member through the pin 43, block 42 and a spacer pin 44. At its lower end. said pin 44 bears in a recess 45 centrally of the plate 32 and passes upwardly through a tubular member 46 extending centrally through the annular spacing member 39, theupper end of the pin bearing upon the underside of a plate 47 centrally thereof. To prevent the passage of pressure upwardly from the chamber 33 T preferably employ a bellows diaphragm 48 of which the plate 32 herein forms the bottom wall. The top wall of this diaphragm is formed by a plate 49 having a central nipple 50 therein screw-threaded into the bottom wall 38 of the annular spacing member 39. Similarly, to prevent the escape of pressure from the valve casing 12, T provide a bellows diaphragm 51-of which the plate 47 forms the upper wall and a plate 52 forms the bottom wall. The plate 52 has a central nipple 53 screw-threaded into the top wall 40 of the annular chamber 39.

These bellows diaphragms, it will be ob served efi'ectually prevent the escape of pressure from one chamber to the other. They eliminate the necessity of using a stuifing box, which is objectionable because it would interfere with and frictionally restrain the movements of the pin 44. This is especially true in the case'of valves used for refrigeration purposes because'the sliding stem would become coated with ice and tend to freeze in the packing.

Also it will be observed that the bellows diaphragms permit of a wider range of movement without strain such as is incident to the useof a simple or plate diaphragm.

It will be observed that the pressure element formed by the plate 32 is made substantially larger than the pressure element formed by the plate or block 42, and the arrangement is such that when the temperature of the room being cooled is at a predetermined point the spring 21 coacting with the pressure on the upper element 42 will balance the pressure on the lower ele* ment 32 and any further lowering of the temperature in the room will permit the valve member to be held to its seat thus entirely cutting off the flow of refrigerant to the coil. The spring in this arrangement may be relatively light because it is assisted in opposing the force applied to the lower pressure element by the pressure flowing through the valve.

For charging the hollow cylinder 35 I preferably provide a valved connection between the inlet side of the valve casing and the pipe 34 leading to the cylinder 35. This connection in the present instance comprlses l a pipe 54 opening into the valve casing at 55 above the transverse partition 14 and opening into the pipe 34 below the regulating valve 10. By the manipulation of a hand operated valve 56 interposed in the pipe 54 a charge of ammonia may be admitted to and then confined in the cylinder 35. If desired a gage 57 may also be provided in the pipe 34 adjacent the cylinder 35 to indicate the pressure and hence the temperature in the room I perature in either of the chambers to its predetermined point will not interrupt the operation of the motor 58 but the lowering of the temperature in both of the chambers will interrupt the operation of the motor.- Herein I have shown thermostats 59 and 59' in the respective chambers. The thermostat 59 is located in the chamber A and is interposed in a circuit 60 connected in one side of the line leading to the motor. The thermostat 59 is located in the chamber B and interposed in the same side of the line. It will be observed that so long as the temperature in one of the chambers remains above the predetermined point, the circuit to the motor is maintained and only upon the lowering of the temperatures in both chambers to the desired points is the circuit interrupted.

In the operation of the system, refrigerant is supplied to the pipe line 4 under the control of the expansion valve 9 operating to maintain a substantially constant pressure in the supply line. Initially the temperatures in the chambers A and B being above the points desired, the regulating valves 10 permit the flow of refrigerant through the expansion coils 3 to the return line 5. This is due to the fact that the pressure of the element in the thermo-responsive cylinder 35 is sufficient when applied to the pressure element 32 to overcome the pressure on the element 42 plus the tension of the spring 21.

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As the temperature in one of the chambers It will be seen that the valve member is operated by a differential in pressure varying with the temperature of the chamber being cooled, and with only a slight rise in temperature the differential increases rapidly with the result that the valve member is positively operated. Thus the regulating valve is extremely sensitive and is capable of maintaining the temperature in the chamber substantially constant.

' The thermostat for controlling the motor circuit may be adjusted so as to be operative just prior tothe complete shutting off of the flow of refrigerant to the coil in the proper chamber.

It will be observed that by a relatively simple construction, I have eliminated troublesome stufling boxes, increased the durability of the valve and at the same time substantially increased its operating efliciency.

I claim as my invention:

1. A regulating valve for refrigeration systems having two opposed pressure elements one arranged to be subjected to the pressure of the refrigerant flowing through the valve and the other arranged to be subjected to an independent and variable prespin.

sure, the last mentioned element being of larger eflective area than the other element and the pressure in either chamber being independent of the pressure in the other chamber, and valve means operable by the effective pressure differential between the two elements, the smaller pressure element having spring means operatively associated therewith coacting with the pressure on the smaller element to balance at apredetermined point the pressure on the larger element.

2. A regulating valve for refrigeration systems comprising, in combination with a valve member to be operated, of operating means therefor including two opposed imperforate pressure elements each in the form of a rigid member, means providing separate chambers for said members, insulation means between said chambers, a pin interposed between said members and extending into the respective chambers, and bellows diaphragms associated with. ,the respective members to prevent communication of'pressure between the two chambers around said 3. In a regulating valve for refrigeration systems, the combination with a. valve member to be operated, of operating means for the valve member including a pair of pressure responsive members, chambers in first mentioned chambers, and means operatively associated with the respective elements to prevent commumcation between the pressure chambers through sald tubular stem.

a 4. A regulatmg valve for refrigeratlon systems and the like comprising, in com bination, a valve casing having a partition therein with a valve port in said partition, a spring-pressed valve member tending to, close said port, said casing on opposite sides of the partition having inlet and outlet ports respectively for refrigerant, means forming with said valve casing a closed chamber communicating with said inlet port, a pressure element operatively associated with the valve member and movably mounted in said chamber so as to respond to the pressure of the refrigerant therein, means providing a second closed chamber in spaced relation to the first chamber, a second pressure element. in said second chamber of substantially larger area than the first pressure element, said second chamber being adapted for connection with a source of thermally responsive pressure fluid, a spacer between said two elements whereby said elements move in unison, and a partition including insulation material, interposed between said two chambers and having an opening therethrough for said spacer. Y

5. A. regulating valve for refrigeration systems comprising, in combination with a valve casing adapted for connection with a sourcev of refrigerantand having a valve member therein, and means for controlling the operation of said-valve member comprising-a chamber communicating with the source of refrigerant, a second chamber communicating with a source of thermally responsive pressure fluid, a' pressure element movably mounted in each of said chambers In testimony whereof, I have hereunto 'afiixed my signature. I

GEORGE HlILGER.

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