US3139903A

US3139903A - Expansion valve with adjustable metering orifice

Info

Publication number: US3139903A
Application number: US90699A
Authority: US
Inventors: Harold J Lonn
Original assignee: Deutsche ITT Industries GmbH
Current assignee: TDK Micronas GmbH; International Telephone and Telegraph Corp
Priority date: 1961-02-21
Filing date: 1961-02-21
Publication date: 1964-07-07
Anticipated expiration: 1981-07-07

Description

July 7, 1964 H. J. LONN 3,139,903

EXPANSION VALVE WITH ADJUSTABLE METERING ORIFICE Filed Feb. 21, 1961 E60 10 jl 2 Sheets-Sheet 1 INVENTOR.

659E040 r]. Lou/v y 7, 1964 H. J. LONN 3,139,903

EXPANSION VALVE WITH ADJUSTABLE METERING ORIF'ICE Filed Feb. 21, 1961 2 Sheets-Sheet 2 IN VENTOR.

L nea .0 I]; LON/V flrraeusys United States Patent 3,139,903 I EXPANSION VALVE WITH ADJUSTABLE METERING ORIFICE Harold J. Lonn, Milwaukee, Wis., assignor to International Telephone and Telegraph Corporation, Baltimore, Md.,

a corporation of Maryland Filed Feb. 21, 1961, Ser. No. 90,699 2 Claims. (Cl. 137-359) This invention relates to a valve structure and more particularly to an expansion valve useful in refrigerating systems.

Valves of this character are in quite common use. They open in response to an increase in temperature at the place to be cooled for admitting vaporized refrigerant (such as Freon) into the expansion coil.

It is advantageous to predetermine the maximum rate of refrigerant flow to the coil to correspond to the capacity of the coil to utilize the expanded refrigerant, or to predetermine the rate of flow to fit the capacity of the compressor. This limiting rate of flow is accomplished by providing a metering orifice in series with the valve port so that the liquid refrigerant passes from the orifice to the valve. In the past, changes in the metering orifices have been difficult and usually necessitated at least a partial dismantling of the valve and a consequent temporary shutdown of the system.

It is one of the objects of this invention to obviate such occurrences and to make it possible to select an appropriate size metering aperture without at all dismantling the valve, and in a relatively simple and rapid manner.

Due to these features, it is possible temporarily to increase the rate of flow of refrigerant to produce immediate chilling of the expansion coil, and yet without danger of overloading the compressor.

This invention possesses many other advantages and has other objects which may be made more clearly apparent from a consideration of one embodiment of the invention. For this purpose, there is shown a form in the drawings accompanying and forming a part of the present specification. This form will now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of this invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a longitudinal cross-sectional view of a valve structure incorporating the invention;

FIG. 2 is a fragmentary sectional view, taken along a plane corresponding to line 2-2 of FIG. 1; I

FIG. 3 is a fragmentary end view of a portion of the valve structure shown in FIG. 1;

FIG. 4 is a sectional view, taken along a plane corresponding to line 4-4 of FIG. 1; and

FIGS. 5 and 6 are fragmentary sectional views, similar to FIG. 4, of modified forms of the invention.

In the form shown in FIGS. 1 to 4, the valve structure is utilized as an expansion valve for refrigerants, such as Freon.

Thus, the valve structure includes a main body 1 having a generally cylindrical portion 2 forming an expansion space 3.

In the present instance, a lateral extension 4 provides an inlet opening 5. A similar lateral extension 6, leading from the expansion chamber 3, is formed integrally with the valve body 1 and serves as an outlet. This outlet 6 may be appropriately connected to the inlet side of an expansion coil.

A conical-shaped wire screen 7 may be inserted into the opening 5 for separating foreign matter from the incoming fluid.

3,139,903 Patented July 7, 1964 The inlet opening 5 has an enlarged portion 8 which, together with opening 5, provides an opening extending laterally entirely across the body 1. Its left-hand end is closed by a gland nut 9 threaded into the left-hand end of the enlarged portion 8. This gland nut will be further referred to hereinafter.

The flow of refrigerant passes toward the left through inlet 5, as viewed in FIG. 1, thence downwardly through a metering aperture 10, through a valve seat member 11, into the expansion chamber 3, past a ball closure 12. The valve seat member 11 may be fastened in an appropriate opening 13 extending from the opening 8' downwardly into the expansion chamber 3.

This ball closure 12 is automatically opened in response to a requirement for additional refrigerant in the expansion coil of the system. Since such uses of the expansion valve are now well-known, further description thereof is unnecessary.

The ball closure 12 is mounted in the upper face of a disc 14 in any appropriate manner. For example, the ball 12 may be held in place by the aid of an upset flange 12a formed on the upper side of the disc 14.

The disc 14 has a central, downwardly directed boss 15 serving as a guide for the upper end of a compression spring 16 which urges theball 12 to closing position.

The lower end of the spring 16 is similarly guided by a boss 17 mounted on a disc 18. This disc 18 is internally threaded for the reception of an adjusting screw 19. This screw 19 is provided with a collar 20 integral with a cylindrical extension or stem 21. The collar 20 rests upon a shoulder 22 formed by the aid of a counterbore of the opening 23. This opening rotatably accommodates the cylindrical extension 21.

The aperture 23 is formed in a fitting 24 having a hollow, upwardly extending, externally threaded portion 25. This extension 25 is threaded into the lower end of the body portion 2. The fitting 24 has a knife-edge flange 26 which serves to seal 011 the body member 2. The periphery of fitting 24 is hexagonal to make it possible to manipulate the fitting 24 by the aid of a wrench.

The screw 19 can be rotated to adjust the force exerted by the compression spring 16. For this purpose, the stem 21 is provided at its end with a non-circular portion 27 by the aid of which the stem 21 may be turned.

The stem 21 is sealed off by the aid of a resilient packing 28 surrounding the stem 21. This packing 28 is urged into sealing relationship by the aid of a packing gland nut 29 threaded into a threaded opening 30 provided in the fitting 24.

In order to enclose the end 27, a cap 31 is threaded on exterior threads formed on the fitting 24. A knifeedge flange 32, located on the fitting 24, seals against the upper edge of the cap 31.

When conditions require it, the disc 14 is urged downwardly against the force of the spring 16 so as to unseat the ball 12 to the position shown in FIG. 1. The mechanism for accomplishing this is illustrated in FIG. 2.

Thus, a pair of thrust pins 33 are mounted for vertical movement in the body 1. The lower ends contact the disc 14. These thrust pins 33 are carried by a disc 34 guided by an extension 35 formed on the body 1.

The disc 34 is urged downwardly by fluid pressure in a A central boss 41 serves to accommodate a conduit 42 leading to a slanting port 43. This slanting port is in communication with the chamber 36. The conduit 42 is in communication with a device sensing temperature, such as a pressure cell or bulb 44. This pressure cell or bulb is located in the space to be refrigerated. Upon an increase in temperature, the bulb 44 causes a volatile filling to expand and to exert fluid pressure in the chamber 36. When the temperature reaches a sufficiently high level, the push pins 33 are operated to depress the ball 12 from its seat 11, thereby opening the valve.

A sheet metal name plate 45 may be disposed, if desired, over the cover member 38.

The size of the metering orifice determines the level of maximum fiow of the refrigerant to the expansion coil. It is desirable at times to make it possible to select a proper sized metering orifice to correspond to the desired maximum flow.

In the past, this has been accomplished by providing removable elements in the mechanism and replacing them to define different sized orifices, as required. This necessitated a dismantling-of the apparatus.

In the present instance, the size of the metering orifice can be adjusted externally of the apparatus simply by turning a stem 46. This stem 46 extends into the inlet opening 8, and integrally carries at its right-hand end a hollow cylinder 47.

This hollow cylinder, as shown most clearly in FIG. 2, has equiangularly spaced

orifices

10, 10a, 10b and 100 of different sizes. Accordingly, by rotating the stem 46, it is possible to cause alignment of the selected orifice with the port extending through the valve seat 11.

To facilitate adjustment, the left-hand end of the stem 46 is flattened, as indicated in FIG. 3, to enable it to be readily turned by the aid of a wrench. Furthermore, indicia 48 may be marked on the head 49 of the gland nut 9. This indicia is intended to cooperate with an arrow 51 marked on the end surface of the stem 46.

In order properly to seal off the stem 46, use is made of a sealing ring 52 around the stem 46. This ring may be of rubber, such as an 'O-ring. A washer 53 may be interposed between the packing ring 52, and the shoulder formed by the left-hand surface of cylinder 47.

A packing gland 54 is urged against the right-hand edge of the cylinder 47. This packing gland is provided with a hub portion 55 defining ashoulder against which another resilient sealing or packing ring 56 may be urged. Adjacent this packing ring 56 is a hollow sight glass 57 (see also FIG. 4) which may be viewed through an opening 58 in the body 1.

Adjacent the right-hand end of the sight glass 57 is another packing gland 59 similar to packing gland 54. This packing gland 59 is also provided with a resilient packing or sealing ring 60. This sealing ring is urged toward the left by the aid of a compression spring 61. The right-hand end of this spring 61 abuts a shoulder 62 formed between the openings 5 and 8 which constitute the inlet to the valve.

By the aid of the compression spring 61, the packing or sealing rings 52, 56 and 60 are placed under compression so as to prevent egress of refrigerant to the exterior of the valve.

In the form shown in FIG. 5, the sight glass 57, as before, is urged against the packing gland 54. This packing gland does not directly contact the hollow cylinder structure 63. Instead, the packing gland 54- rests on the shoulder 64 defined by the aperture 65 of smaller diameter than the aperture 8.

The hollow cylinder 63, similar to hollow cylinder 47, bottoms on the shoulder formed between the aperture 66 and the aperture 65. The stem 67 is capable of angular adjustment as before. It is sealed by the aid of a resilient packing collar or ring 68 urged into packing relation by the aid of a gland nut 69.

In the form shown in FIG. 6, the sight glass is omitted. Instead, the gland 54 is urged inwardly against the righthand edge of the hollow cylinder 47 by the aid of compression spring 70.

The capability of adjusting the size of the metering orifice is advantageous temporarily to increase or decrease the rate of fiow of refrigerant to the expansion coil. Thus, the size of the metering orifice may be decreased in the event that it is desired to start the system from a warm condition. Under such circumstances, quick cooling can be effected without overloading the compressor. After sufficient cooling has been effected, the orifice size may be readily increased to that desired.

, between an intermediate portion of said inlet opening and the outlet opening, said passage including a port; a rotary hollow cylinder guided in said inlet opening and overlying said port; said cylinder having angularly spaced openings optionally registrable with the port to form a metering orifice; the interior of the cylinder being in communication with the inlet opening; a stern for the cylinder extending out of the body and rotatable to adjust the cylinder for registering any one of said angularly spaced openings with the port; one end of said cylinder forming an annular shoulder around the stem; a resilient sealing ring disposed on the shoulder; a packing nut around the stem and forming an abutment for the ring; a packing gland engaging that end of the cylinder opposite the stem; a resilient sealing ring adjacent the side of the gland opposite the cylinder; means resiliently urging the packing gland against the cylinder; a sight glass interposed between hte resilient urging means and the packing gland; and sealing means between the sight glass and the resiliently urging means.

2. In a valve structure: a valve body having an inlet opening and an outlet opening; said inlet opening extending entirely through the valve body; there being a passage between an intermediate portion of said inlet opening and the outlet opening, said passage including a port; a rotary hollow cylinder guided in said inlet opening and overlying said port; said cyinder having angularly spaced openings optionally registrable with the port to form a metering orifice; the interior of the cylinder being in communication with the inlet opening; a stem for the cylinder extending out of the body and rotatable to adjust the cylinder for registering any one of said angularly spaced openings with the port; one end of said cylinder forming an annular shoulder around the stem; a resilient sealing ring disposed on the shoulder; a packing nut around the stem and forming an abutment for the ring; a first packing gland engaging that end of the cylinder opposite the stem; a resilient sealing ring adjacent the side of the gland opposite the cylinder; means resiliently urging the first packing gland against the cylinder; a sight glass interposed between the resiliently urging means and the first packing gland; a second packing gland interposed between the sight glass and the resiliently urging means; and a resilient sealing ring around the said second packing gland.

References Cited in the file of this patent UNITED STATES PATENTS 967,009 Frishmuth Aug. 9, 1910 1,088,103 Schreidt Feb. 24, 1914 1,393,615 Foltz Oct. 11, 1921 1,887,235 Cornelius Nov. 8, 1932 2,062,896 Martocello Dec. 1, 1936 2,101,356 Zak Dec. 7, 1937 2,524,569 Matteson Oct. 3, 1950 2,570,322 Christopher Oct. 9, 1951 2,743,552 Hunter May 1, 1956 2,899,980 Loebel Aug. 18, 1959 2,973,325 Barrows Feb. 28, 1961

Claims

1. IN A VALVE STRUCTURE: A VALVE BODY HAVING AN INLET OPENING AND AN OUTLET OPENING; SAID INLET OPENING EXTENDING ENTIRELY THROUGH THE VALVE BODY; THERE BEING A PASSAGE BETWEEN AN INTERMEDIATE PORTION OF SAID INLET OPENING AND THE OUTLET OPENING, SAID PASSAGE INCLUDING A PORT; A ROTARY HOLLOW CYLINDER GUIDED IN SAID INLET OPENING AND OVERLYING SAID PORT; SAID CYLINDER HAVING ANGULARLY SPACED OPENINGS OPTIONALLY REGISTRABLE WITH THE PORT TO FORM A METERING ORIFICE; THE INTERIOR OF THE CYLINDER BEING IN COMMUNICATION WITH THE INLET OPENING; A STEM FOR THE CYLINDER EXTENDING OUT OF THE BODY AND ROTATABLE TO ADJUST THE CYLINDER FOR REGISTERING ANY ONE OF SAID ANGULARLY SPACED OPENINGS WITH THE PORT; ONE END OF SAID CYLINDER FORMING AN ANNULAR SHOULDER AROUND THE STEM; A RESILIENT SEALING RING DISPOSED ON THE SHOULDER; A PACKING NUT