US2278002A - Liquid level responsive valve - Google Patents

Description

March 31,1942. P. H. THOMPSON 2,278,002

LIQUID LEVEL RESPONS IVE VALVE .Fiied June 25, 1939 2 Shets-Sheet 1 INVENTOR PARKE H. THOMPSON ATTORNEY.

March 31, 1942. H, THOMPSON 2,278,002 I LIQUID LEVEL RESPONSIVE VALVE 7 Filed June 25, 1959 2 Sheeis-Sheet 2 INVENTOR PARKE H.THOMPSONY ATTORNEY Patented Mar. 31, 1942 UNITED STATES PATENT OFFKIE Claims.

This invention relates generally to control valves and, more particularly, to a liquid level responsive self-compensating valve especially,

though not exclusively, adapted for use in connection with refrigerating systems and the like.

My invention has for its primary objects the provision of a control valve of the type stated, which is exceptionally simple and economical in construction, which has a relatively small number of moving parts and is very rugged and durable, which is automatically self-compensating against over-travel, which is exceedingly efficient in operation, which is designed for compactness and simplicity of assembly, and which is highly satisfactory in the performance of its stated functions.

And with the above and other objects in view, my invention resides in the novel features'of form, construction, arrangement, and combination of parts presently described and pointed out in the claims.

In the accompanying drawings (2 sheets):

Figure 1 is a longitudinal sectional view of a control valve constructed in accordance with and embodying my present invention;

Figures 2 and 3 are enlarged transverse sectional views of the valve, taken approximately along the lines 2-2 and 3-3, respectively, Figure 1; and

Figure 4 is a diagrammatic view of a refrigerating system incorporating a control valve of my present invention.

Referring now in more detail and by reference characters to the drawings, A designates generally a preferred form of control valve constructed in accordance with my present invention, which includes a base ring I having upper and lower seat faces 2, 3, each provided with an annular series of internally threaded recesses 5, 6. Along the inner peripheral margins of the seat faces 2, 3, the base ring I is recessed or cut away in the provision of annular channels or gasket recesses 'I, 8, and is further provided with a pair of diametrally opposed internally threaded apertures 9, Ill, for connection respectively with a supply pipe II and a discharge pipe I2.

Welded or otherwise hermetically sealed within, and extending horizontally across, the base ring I, is a disk-like partition wall I3 marginally extending across the recess 8 with its under face preferably disposed slightly below the plane of the seat face 3 and provided adjacent its outer periphery with an arcuate passage-forming slot or opening I I and on its under face with a narrow annular recess or groove IS. The wall or all plate I3 is further provided with a relatively large centrally disposed opening It for accommodating a downwardly presented tube H interiorly provided with an annular insert I0 bored and ground to provide a valve seat forming neck I9 having the contour or shape of a Venturi constriction, all as best seen in Figure l and for purposes presently fully appearing.

Also welded or otherwise hermetically sealed within, and extending horizontally across, the base ring I, and disposed in spaced parallel relation to the plate I3, is a base plate marginally extending across the recess 1 with its upper face preferably disposed slightly above the horizontal plane of the seat face 2. In its upper face, the base plate 20 is provided with a preferably shallow annular recess 2| of relatively large diameter, the horizontal bottom wall 22 of which is provided with a centrally positioned internally thread-ed aperture 23. Welded on the under face of the bottom wall 22 and extending axially in concentric alignment with the aperture 23, is a packing gland 23, all as best seen in Figure 1 and for purposes presently appearing.

I-lermetically secured around its peripheral margins to, and extending obliquely across, the base ring I, is a deflecting wall 24 disposed in front of the inlet aperture 9 and above the passage I4, all as best seen in Figure 1 and for purposes presently fully appearing.

Peripherally secured upon the upper face of the plate 20 and extending horizontally across the recess 2I in the formation of a chamber a, is a diaphragm 25 centrally apertured, as at 26, and provided on its under face with a lower pressure plate 21 centrally apertured, as at 28, in registration with the diaphragm aperture 26. On its upper face, the diaphragm 25 is provided with an upper pressure plate 29 having a downwardly extending hub 30 projecting through the diaphragm aperture 20 and snugly secured in the aperture 28 of the lower pressure plate 21, the hub 30 being centrally bored, as at 3!, and provided with a pair of diametrally opposed oblique pilot passages 32.

Mounted upon the upper face of, and in peripheral registration with, the diaphragm 25, is a shallow cap 33 forming, in co-operation with the diaphragm 25, a pilot valve chamber b and provided with a centrally positioned aperture 34 in alignment with the hub aperture 3I of the pressure plate 29.

Mounted rigidly in, and extending through, the hub aperture 3|, is a tubular valve stem 35 projecting upwardly through the cap aperture 3 and downwardly through the packing gland 24, in which latter the stem is sealed by a conventional packing ring 35 held in place by a gland nut 31. At its lower end, the valve stem 35 projects co-axially through the tube l1 and is provided at its lower end with an annular valve plug 38 shaped for co-operative engagement in the valve seat l9.

Interiorly of the hub aperture 3], the valve stem 35 is provided with a pair of diametrally opposed apertures 39 in registration with the pilot passages 32. Fixed interiorly of the valve stem 35 preferably just beneath the apertures 39, is a seat-forming sleeve 40 for co-operation with the needle-end 4! of a valve pin 42 shiftably mounted in, and projecting upwardly beyond the upper end of, the valve stem 35 and provided at its upper end with an annular washer 43 for retentive abutting engagement with the upper end of a small compression spring 44, in turn, at its lower end abuttingly engaged against the upper margin of the valve stem 35, all as best seen in Figure 1.

The base plate 29 is further provided with a pair of intersecting drill holes 45, 46, respectively opening to the chamber a and the upper face of the base plate 29 in the provision of a vent passage (2. Similarly, the cap 33 is provided with a pair of non-intersecting overlying drill holes 41, 48, transversely connected by an aperture or leak port 49 for valve seat forming co-operation with the needle-end of a threaded valve screw 59 held in any position of adjustment by a lock nut 5| and adapted to adjustably control the rate of leakage flow through the leak port 49 from I the chamber b. It may be stated in this connection that, if desired, such adjustable leak port structure may be omitted and suflicient clearance provided between the aperture 34 and the outer face of the valve stem 35 to allow a fixed amount of leakage in the manner more fully described and set forth in my co-pending and related application Serial No. 272,373, filed May 8, 1939.

Welded or otherwise fixed at its lower end upon the upper face of, and extending perpendicularly upwardly from, the base plate 20, is a channel-shaped upright or supporting post 52 having a pair of opposed flanges 53 preferably integrally connected by a transversely extending web-member 54. Mounted in and extending transversely between the flange members 53 adjacent the upper end of the upright 52, is a pintle 55 for swingable engagement with a mounting lug 56 of a float ball 51 substantially smaller in diametral size than the base plate 20, all as best seen in Figures 1 and 2 and for purposes presently fully appearing.

Swingably suspended at its upper end from the mounting lug 56 in outwardly spaced relation to the pintle 55, is a link 58 pivotally connected at its lower extremity to one end of an actuating lever 59, in turn, pivotally mounted adjacent its opposite end upon a fulcrum pin 69 supported by a fulcrum plate 6| welded on, and extending obliquely across the upper end of, the valve stem 35, the lever 59 being preferably integrally provided with a horizontal web portion 62 projecting beyond the fulcrum pin and abuttingly engaging the upper end of the valve pin 42, all as best seen in Figures 1 and 3 and for purposes projecting rim 65 for disposition in the gasket recess 8 in gas-tight engagement with a gasket 65. The ring 64 is also provided with a plurality of apertures 66 in registration with the base ring apertures 6 for receiving stud bolts 61 for drawing the rim 64 tightly upon the base ring I in the formation of a sealed intake chamber d.

The shell 63 is interiorly provided with an annular upwardly opening channel-shaped ring 68 for retentively receiving the lower end of a cylindrical strainer screen 69, in turn, at its upper end retentively disposed in the annular slot 15 of the partition plate I3, all as best seen in Figure 1 and for purposes presently appearing.

Similarly mounted upon, and extending upwardly from, the base plate 20, is a preferably metallic cylindrical or tubular shell 19 provided at its upper end with a dome-shaped top wall H and at its lower margin with an external annular flange ring 12 having a projecting rim 13 for disposition in the gasket recess 1 in gas-tight engagement with a gasket 13'. The ring 12 is also provided with a plurality of apertures 14 in registration with the apertures 5 of the base ring I for receiving stud bolts 15 for drawing the shell 10 tightly upon the base ring I in the provision of a sealed float chamber e.

Welded or otherwise hermetically mounted in and extending through the shell 10, is a connection nipple 76 for conventional connection with a liquid communication line 11. Similarly welded or otherwise hermetically sealed in and extending through the dome-shaped top wall H of the shell 70, is a second connection nipple 18 for conventionally receiving a gas communication line 19, all as best seen in Figure l and for purposes presently appearing.

Although, as has been stated, valves constructed in accordance with my present invention may be efiiciently employed in a variety of installations, for purposes of illustration, I have chosen to describe its use and operation in connection with a conventional type of refrigeration system including a compressor B, a liquid condenser-receiver C, and a conventional type of evaporator D. The compressor outlet is conventionally connected through the line 80 to the condenser-receiver C, which is, in turn, connected through the line H to the inlet aperture 9 in the base ring I of the control valve A. The outlet aperture I0 in the base ring I of the valve A is connected through the line I2 to the intake side of the evaporator D. The discharge side of the evaporator D is conventionally comiected through the line 8| to the suction or intake side of the compressor B. The liquid communication line 1! of the valve A is connected to a relatively low point of the evaporator D and the gas communication line 19 to a relatively high point of the evaporator D, so that the liquid level and gasliquid phase relationship within the chamber e are substantially identical to those within the evaporator D.

In use, the liquid enters the valve inlet aperture 9 and is deflected downwardly by the partition plate or baffle 24 through the aperture l4 and through the strainer 69 into the intake chamber d. Initially the liquid level in the evaporator will be comparatively low, so that the float ball 5! will drop down to its lowest point, shifting the link 58 downwardly, in turn, swinging the lever 59 about the fulcrum pin 60 and permitting the pilot valve pin 42 to be shifted upwardly from seated engagement with the seatforming sleeve Ml under the combined pressure of the'high-pressure liquid in the intake chamber d and the bias of the spring 45. Asthe valve pin 42 moves upwardly, high-pressure liquid flows through the pilot passages 32 into the chamber 1), exerting downward pressure upon the diaphragm 25, overcoming the bias of the diaphragm spring 25, andshifting the valve stem 35 downwardly, thereby moving the annular valve plug 38 out of seated engagement and permitting high pressure fluid to flow upwardly through the tube H, the outlet aperture I0, and the conduit line I2 to the evaporator D. When the liquid level within the evaporator D and the valve chamber e reaches a suificient level, the float ball 51 is raised. shifting the link 58 in the reverse direction and swinging the actuating lever 59 in the reverse direction to restrict or entirely out oi? the flow of high-pressure liquid through the pilot passages 32 into the pilot chamber b, thereby permitting the diaphragmdepressing high-pressure liquid to leak or expand outwardly through the leak port and permit the valve stem 35 to be shifted upwardly into valve throttling or valve closing position, as the case may be,

It will be seen that, in order to permit the pilot valve pin 44 to shift upwardly, the outer end of the lever 59, which is connected to the lower end of the link 58, must move downwardly with re- 7 spect to the fulcrum pin 60. Conversely, to shift the pilot valve pin 44 into closing position, the outer end of the lever 59, which is connected to the link 58, must move upwardly with respect to the fulcrum pin 60.

By reason of the fact that the fulcrum pin 60 and its associated fulcrum plate are mounted directly on the upperend of the valve stem 35, and move downwardly therewith immediately upon opening movement of the valve stem 35, the fulcrum pin 60 will accordingly be shifted downwardly with respect to the outer end of the lever 59, a movement which has the eifect of shifting the pilot valve pin 44 toward closed position, thereby automatically reducing the flow of highpressure liquid into the pilot chamber 19 and permitting the valve stem 38 to be shifted up into closer throttling position, thereby restricting the flow of high-pressure liqu d to the evaporator D in advance of and by way of anticipating the return flow of the admitted liquid, preventing socalled wild hunting or cycling, and providing a self-compensating valve operation. In other words, valves constructed in accordance with the present invention automatically compensate against various types of false-positioning, such as under-travel and over-travel.

The valve most efficiently accomplishes the objects stated, and it should be understood that changes and modifications in the form, construction, arrangement, and combination of the several parts of the valve may be made and substituted for those herein shown and described without departing from the nature and principle of my invention.

Having thus described my invention. what I claim and desire to secure by Letters Patent is:

1. A level responsive fluid control comprisin a valve body having high and low pressure chambers, valve means disposed therebetween, servomotor means operably connected to the valve means and having communication with the high pressure chamber, and liquid level responsive means for admitting fluid from the high pressure chamber to the servo-motor means to open the valve means,'said liquid level responsive means including a pilot valve carried by, and an actuating lever fulcrumed on, said valve means so that the energizing effect of the servo-motor means is reduced upon opening movement of the valve means.

2. A valve comprising a body having inlet and outlet chambers separated by a wall having a seat-forming orifice, an auxiliary chamber having a diaphragm disposed thereacross, a tubular stem mounted on and extending through the diaphragm and opening at one end to the inlet chamber and at the other end to the auxiliary chamber, a valveplug mounted on the stem for seating co-operation with the orifice, a valve pin shiftably mounted in the tube for controlling the flow of fluid through the stem from the inlet chamber to the auxiliary chamber, an actuating lever fulcrumed on and shiftable with the stem, and level responsive means operably connected to the lever.

3. A float control valve comprising a pair of matching shells connected by an annular ring, spaced parallel upper and lower partitions mounted in and extending transversely across the ring, an oblique baffle mounted between the partitions and the ring forming a valve body having upper and lower chambers and intermediately disposed inlet and outlet chambers, inlet and outlet means extending through the ring and opening into the inlet and outlet chambers respectively, said lower partition being provided with valve-seat forming means opening into the outlet chamber and an aperture connecting the inlet chamber with the lower chamber, floatball means mounted in the upper chamber, servo-motor means mounted on the upper partition, a valve-stem extending through the partitions and having a plug adapted for seated engagement with the valve-seat forming means, and pilot-valve means controlled by the floatball for connecting the lower chamber to the servo-motor means for operating the valve-stem.

4. A float control valve comprising a pair of matching shells connected by an annular ring, upper and lower partitions mounted in and extending transversely across the ring in spaced parallel relation, means mounted between the partitions and extending across the ring in the formation of a valve body having an upper chamber, a lower chamber, and intermediate inlet and outlet chambers, inlet and outlet means extending through and opening into the inlet and outlet chambers respectively, float-ball means mounted in the upper chamber, said upper partition being providedupon its upper face with a recess, a diaphragm mounted across the recess, a cap mounted over the diaphragm, said lower partition being provided with an aperture connecting the inlet and lower chambers, a tube extending through the lower partition connecting the outlet and lower chambers, a tubular valvestem fixed in the diaphragm and extending through the cap, the partitions, and the tube, a valveplug carried by the stem and adapted for normally seated engagement with the tube, and pilot valve means mounted in the tubular stem and controlled by the float-ball for admitting pressure from the lower chamber to the space between the cap and diaphragm for shifting the valve plug.

5. A float control valve comprising a valve body having an upper float chamber and a lower sump chamber respectively having lower and upper walls spaced apart in the provision of an intermediate passage having imperforate wall means for dividing the passage into an inlet duct and outlet duct, the inlet duct being directly in communication with the sump chamber for introducing high pressure fluid into said sump chamber and the outlet duct being directly in communication with the sump chamber through an orifice having valve means operably disposed therein, pressure-actuated servo-motor means disposed within the float chamber and actuable 10 responsive to pressure difierential between the sump chamber and the float chamber, said servo-motor means being operatingly connected to the valve means, a float member operatively mounted within the float chamber, and pilot valve means actuable responsive to movement of the float member for controlling the flow of high pressure fluid to the servo-motor means from the sump chamber.

PARKE H. THOMPSON

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