US2768513A

US2768513A - Pressure control system

Info

Publication number: US2768513A
Application number: US449170A
Authority: US
Inventors: Joseph I Morrison
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-08-11
Filing date: 1954-08-11
Publication date: 1956-10-30
Anticipated expiration: 1973-10-30

Description

06h 30, 1956 J. l. MORRISON PRESSURE CONTROL SYSTEM Filed Aug. ll, 1954 JNVENToR. 20M/JW van..

Unite PRESSURE CNTRGL SYSTEM ll'oseph I. Morrison, Lincolnwood, lil.

Application August 11, 19524, Serial No. @$9,176

4 Claims. (Cl. 62-127) This invention relates to a pressure control system and more particularly to a liquid level float control valve assembly adapted for use in refrigeration systems or the like.

In systems wherein a float-operated valve is utilized in conjunction with a receiver for the refrigerant, prior to the latter being introduced into the expansion charnber, the float-operated valve is repeatedly opening and closing during operation of the system because'of the fact that there occurs a feedback of pressure to the valve from the receiver which effects neutralization of the pressure differential across such valve after only a very short time that the valve is opened by the float. The result of this frequent intermittent operation is that the various parts of the valve are subjected to excessive wear and, in addition, considerable noise results during operation of the system. To minimize the frequency of operation of the float-actuated valve, a biasing spring was incorporated which biased the valve into closed relation so that a considerable drop in the level of the fluid accumulated in the receiver was required before the valve would open. However, in such a situation, there resulted a substantial pressure drop across the valve and as a result there often occurred partial expansion of the refrigerant when the valve opened with the result that there was a refrigerating effect on various parts of the valve which caused congealing of the lubrication for the moving parts of the valve and stiffness of operation of the valve.

Thus, it is an object of this invention to provide a pressure control system which minimizes maintenance problems and is simple and inexpensive to install even on existing refrigeration installations.

It is a further object of this invention to provide a pressure control system wherein a controlled pressure differential may be maintained across the float-actuated valve without excessive opening and closing of the valve occurring and also which will not adversely affect the viscosity of the lubricant for the valve and operation of the valve.

It is a further object of this invention to provide a pressure control system which is not beset with the additional disadvantages aforenoted which were commonly associated with refrigerating systems of this type.

Further and additional objects will appear from the description, accompanying drawing, and appended claims.

In accordance with one embodiment of this invention, a pressure control system is provided comprising a hoilow member for accumulating therein fluid under a predetermined pressure, and a first valve unit disposed adjacent said hollow member and including an intake port for receiving the iluid at a greater pressure than the predetermined fluid pressure within said member. The first valve unit also includes a valve biased into seating relation with respect to a valve seat formed in said first valve unit. Protruding from the valve is an elongated stem having one end thereof terminating within the hollow member. Operatively connected to the terminating end of the stem is a float piece which is responsive to the level of the accumulated fluid within the hollow member. The float piece effects unseating of the valve upon the level of the accumulated fluid dropping below a given line. An output port is provided in the first valve unit which is spaced from the intake port and communicates with the intake side of an adjustable metering valve. The metering valve in conjunction with the float piece-actuated valve of the rst valve unit effect reduction of the fluid pressure to a point intermediate the predetermined fluid pressure within the hollow member and the fluid pressure at the intake port of said first valve unit. Communicating with the outlet side of the metering valve is an adjustable third valve unit which also communicates with the interior of the hollow member. The third valve unit is provided with a spring biased valve seat formed within said third valve unit intermediate the communicating portions thereof. The force of the spring bias may be adjusted to compensate for the pressure differential between the communicating portions of the third valve unit.

For a more complete understanding of this invention, reference should be made to the drawing wherein a fragmentary vertical sectional view of the improved pressure control system is shown.

The improved pressure control system, as shown in the drawing in this instance, comprises a hollow member or reservoir 10 in which is accumulated a predetermined amount of fluid 11. When the improved pressure control system is installed in a refrigerating system, the fluid is a refrigerant which, prior to reaching the control system, has been compressed to a given pressure and then condensed. Upon leaving the reservoir 1li the refrigerant is introduced into the expansion chamber, not shown, wherein the refrigerant is expanded and is returned Wholly or partially to a gaseous state.

The reservoir 10, in this instance, comprises a cylindrical member 12 which is closed at one end, as shown in the drawing, by a plate 13. The plate is secured to the sleeve member 12 by a plurality of bolts or screws 14 which are disposed within suitable openings 17 formed in the margin of the plate. The ends of the bolts or screws are threaded into openings 15 formed in an annular outwardly extending collar 16 formed about the periphery of the member and spaced axially from the end thereof. The side of plate 13, adjacent sleeve 12, is provided with an annular groove 18 which is adapted to accommodate the end of sleeve 12. A suitable packing material Ztl is disposed within the groove 18 to prevent leakage of the fluid from the reservoir through the groove.

Plate 13 is provided with an axially extending pro-- tuberance 21 which has an elongated cavity 22 formed in a portion thereof. Cavity 22 is adapted to accommodate the first of an open and close type valve unit 23. Protuberance 21 is likewise provided with a second elongated cavity 24 which is disposed beneath and in substantially parallel relation with cavity 22 and is adapted to accommodate a metering valve unit 25 at one end thereof. The opposite end 19 of cavity 24 communicates with the interior of the reservoir 1t); however, a second open and close type valve unit 26 is disposed within such communicating end.

Cavities

22 and 24 are interconnected by a transversely extending passageway 27 formed in protuberance 21.

The first open and close Itype valve unit 23 is provided with an elongated sleeve portion 2S having the periphery of tie center portion thereof threadably mounted within an internally threaded countersunk outer end Sii of cavity 22. Subsequent to sleeve portion 23 being positioned within cavity 22, a cap 31 is threaded inte end 36 so as to seal olf the end of cavity 22. Cap 31 is provided with an open end pocket 32 which is axially aligned and communicates with cavity 22. Pocket 32 is adapted to accommodate one end portion 23a of sleeve 23 so that sleeve portion 23a is out of Contact with the pocket, thereby providing a passageway through which fluid is free to pass. Sleeve portion 28a has a center bore formed therein in which is disposed a filter 33 through which the fluid is caused to pass before flowing from cavity 22 to connecting passageway 27. A second or opposite end pontion 28b of sleeve 23 extends into cavity 22 in a direction toward reservoir it). Sleeve portion 28b is hollow and is adapted to threadably accommodate therein a valve seat piece 34 against which a ball-type valve 35 is biased into close-Off relation. rThe ball valve 35 is held in seating relation with seat 34 by a plunger or stem 36 which is supported for reciprocntory movement by a bearing sleeve 37, the latter communicating at one end with the interior of thc reservoir and the other end with cavity 22. An end 33 of plunger 36 terminates, subsequent to passing through bearing sleeve 37, within the interior of the reservoir 1G and is pivotally connected to a link piece 40 which, in turn, is pivotally connected to a bell crank type of lever 41 which is disposed within the interior of the reservoir. Bell crank lever 4E, in turn, is pivotally connected at point 42 to an inwardly projecting stud 43, the latter being threadably mounted on the inside face of plate 13. Protruding from lever 41 infto the reservoir interior is a float piece 44 which comprises a stern 44a and a floatable ball 44h aflixed to the end of stem 44:1. The oppoiste end of stern 44a terminates within a suitable pocket 45 formed in lever 4i. so that the float piece and lever move as a unit. The hall 44!) floats on the level of the fluid 11 accumulated within the reservoir l and once the level of the fluid drops below a predetermined line, the float piece 44 will cause bell crank lever 41 to pivot in a counterclockwise direction about point 42 as an axis and effect longitudinal movement of plunger 31 and unseating of ball valve 35. Once ball valve 35 is unseated, fluid is permitted to flow therepast from an intake port 50 formed in the outer end B of cavity 22, as seen in the drawing. The pressure of the fluid introduced through intake port 50 is substantially greater than the pressure of the fluid accumulated within the reservoir. The plunger 36 is biased by a coil spring 46 in a direction to the right, as viewed in the drawing, so as to effect closing of the valve 35 on the valve seat 34 until float ball 4417 has dropped a predetermined amount within the reservoir. Thus frequent intermittent operation of the valve, as heretofore experienced in prior installations, is avoided. The coil spring 46 embraces a portion of the plunger and is disposed between the sleeve bearing 37 and a threadably mounted nut 47 secured to the plunger 36 intermediate bearing 37 and ball valve 35. The amount of bias exerted by spring 46 may be varied by adjustment of nut 47 and, therefore, pressure differential across the valve seat 34 may be effectively controlled. Sleeve portion 28b is provided with a plurality of openings 43 to permit the fluid flowing past the ball valve 35 to find its way to the connecting passageway 27.

The metering valve unit 25, which is disposed at the the juncture 29 of passageway 27 and cavity 24, is provided with a threadably mounted plug 51 which is adapted to restrict the area of the juncture 29. Plug 51 has an exposed end 51a having a faceted periphery to accommodate a wrench for ready adjustment of the relative position of the plug within cavity 24. The combined effect of ball valve 35 and plug 51 is to effect reduction of the fluid pressure to some point intermediate the pressure of the fluid within the reservoir and the pressure of fluid valve 55 is biased by means of a coil spring 56 into closed position with respect to the shoulder 54. The tension of the coil spring 56 may be varied by a plug 57 which is threadably mounted to -the casing 52. The adjustment of the plug will determine what pressure differential between cavity 24 and the interior of reservoir 10 must develop before the valve is unseated.

By cooperation and proper adjustment of valve units 23, 25, and 26, there is a step reduction in pressure of the fluid from the intake pont 50 to the interior of the reservoir thereby effecting smoother, less noisy operation of the system with but a minimum of wear on the valve incorporated in the system. The frequency of operation of valve unit 23 is reduced, as heretofore indicated, by the utilization of coil spring 46. Furthermore, the metering valve prevents the occurrence of a sudden drop of pressure across valve unit 23 which might have an adverse effect on the operation of the valve unit 23 itself. Valve unit 26 prevents the possibility of back-up of the fluid in the system.

While the improved pressure control system has been described in connection with a refrigerating system, it is to be understood, of course, that it is not limited to this particular use but has application in other types of systems wherein a gradual or step reduction in pressure is desired.

While a particular embodiment of this invention is shown above, it will be understood, of course, that the invention is not -to be limited thereto, since many modifications may be made, and it is contemplated, therefore, by 4the appended claims, to cover any such modifications as fall within the true spirit and scope of this invention.

l claim:

1. A pressure control system comprising a reservoir for accumulating therein fluid under a predetermined pressure, a first valve unit disposed adjacent said reservoir and including an intake port for receiving the fluid at a greater pressure than the predetermined fluid pressure within said reservoir, an outlet port for discharging the fluid at a pressure intermediate the predetermined llnid pressure within said reservoir and the fluid pressure at the intake port of said valve unit, a valve seat intermediate said intake and outlet ports, and an adjustable valve having one end thereof terminating within said reservoir and being responsive to the amount of fluid accumulated therein and the other end thereof being seatable on said valve seat upon said one end being responsive to a predetermined accumulation of fluid within said reservoir; resilient means engaging said adjustable valve and biasing said adjustable valve onto said valve seat; an adjustable metering second valve unit having one side thereof communicating with the outlet port of said first valve unit; and a third valve unit having the intake end thereof communicating with the opposite side of said metering valve unit, the outlet end of said third valve unit communicating with said reservoir, a valve seat intermediate the ends of said third valve unit, a valve disposed within said third valve unit intermediate the outlet port and valve seat thereof and biased into seating relation with respect to the latter, said latter valve disposed within said third valve unit also being seated when the fluid pressure in said reservoir exceeds the fluid pressure in said second valve unit, and means adjustably mounted on said third valve unit for varying the amount of bias on the valve therefor.

2. A pressure control system comprising a reservoir for accumulating therein fluid under a predetermined pressure, and a plurality of valve units for said reservoir arranged in series relation; said valve units including a first unit having an intake port for receiving fluid at a greater pressure than the predetermined fluid pressure within said reservoir, a valve normally biased into seating relation with respect to a valve seat formed within said first valve unit, adjustable resilient means biasing said valve into seating position with said seat in said first valve unit, a float piece connected to said valve and disposed within said reservoir and responsive to the level of fluid accumulated therein, said iioat piece effecting unseating of said Valve upon the accumulated fluid within said reservoir being below a given level; an adjustable metering second valve unit having the intake side thereof communicating with an outlet port formed in said rst valve unit and effecting reduction of the iiuid pressure to a pressure intermediate the fluid pressure within said reservoir and the iiuid pressure at the intake port of said first valve unit; and a third unit having an intake port cornmunicating with the outlet side of said second unit, an outlet port communicating with the interior of said reser voir, a valve seat intermediate the intake and outlet ports thereof, and a valve biased into seating engagement with thc latter valve seat, the bias on said latter valve being adjustable to compensate for a predetermined fluid pressure differential between the intake and outlet ports of said third unit, said latter valve being engageable with said latter valve seat when the liuid pressure in said reservoir exceeds that in said third valve unit.

3. A pressure control system comprising a reservoir for accumulating therein iiuid under a predetermined pressure, and a plurality of valve units for said reservoir arranged in series relation; said plurality of valve units including a iirst unit having a housing mounted on said reservoir provided with an intake port for receiving liuid at a pressure greater than the predetermined fluid pressure within said reservoir, an outlet port spaced from said intake port, a valve seat formed in said housing intermediate the intake and outlet ports thereof, a valve mounted within said housing and spring biased into seating engagement with said valve seat, said valve having an elongated stem, the end of which terminates within said reservoir, and a lioat piece disposed within said reservoir and connected to the terminating end of said valve stem, said iioat piece being responsive to the level of the iiuid accumulated within said reservoir and effecting unseating of said spring biased valve when the accumulated fluid within said hollow member is below a predetermined level; an adjustable metering second valve unit having the intake side thereof communicating with the outlet port of said iirst valve unit for effecting a predetermined reduction of iiuid pressure to a point intermediate the predetermined iiuid pressure within said reservoir and the tluid pressure at the intake port of said tirsttvalve unit;

and a third valve unit being mounted on said reservoir 4 and having the intake port formed therein in communication with the outlet side of said metering valve unit, an outlet port communicating with the interior of said reservoir, and a valve biased into seating relation with respect to a valve seat formed intermediate said intake and outlet ports to compensate for the fluid pressure differential on opposite sides of said valve seat, said third valve being engageable with its seat upon the fluid pressure in said reservoir exceeding that in said third valve unit.

4. A pressure control system comprising a hollow member for accumulating therein iiuid under a predetermined pressure; a rst valve unit mounted on said hollow member and including a casing provided with an intake port for receiving uid at a pressure substantially greater than the tiuid pressure within said hollow member, a valve biased into seating relation with respect to a valve seat formed within said casing, a stem formed on said valve terminating within said hollow member, a bell crank lever pivotally mounted within said hollow member and being pivotally connected to the terminating end of said stern at a point spaced from the pivotal axis of said lever, and a iioat piece disposed within said hollow member and protruding from said lever at a point spaced from the pivotal axis or" said lever, said float piece effecting unseating of said valve upon the accumulated iiuid within said hollow member dropping below a predetermined level; a metering valve unit communicating with an outlet port formed in said first valve unit and provided with an adjustably mounted element for varying the size of the passageway leading from said iirst unit, said adjustable element cooperating with the valve of said first valve unit to etect reduction of the fluid pressure to a point intermediate the predetermined fluid pressure within said hollow member and the fluid pressure at the intake port of said first valve unit, and a third valve unit mounted on said hollow member and having a portion thereof communicating with said metering valve, a second portion thereof communicating with the interior of said hollow member, and a valve spring biased into seating relation with respect to a valve seat disposed intermediate said communicating portion, the tension of said spring bias being adjustable to compensate for the fluid pressure differential between the communicating portions of said third valve unit.

References Cited in the iile of this patent UNITED STATES PATENTS 1,525,334 Stengel Feb. 3, 1925 1,901,633 Clemmons Mar. 14, 1933 1,970,074 Brenner Aug. 14, 1934