US2683582A - Snap action regulator valve - Google Patents

Description

July 13, 1954 AN. Kr-:RR

SNAP ACTION REGULATOR VALVE 2 Sheets-Sheet l Filed Jan. l5, 1950 FIG.

`LIQUID @As INVENTOR. A N K ERR ATTORNEYS July 13, 1954 A N, KERR 2,683,582

SNAP ACTION REGULATOR VALVE Filed Jan. 13; 195o 2 sheets-sheet 2 INVENTOR. A.N. KERR ATTORNEYS Patented `luly 13, 1954 UNITED STATES PATENT OFFICE SNAP Ao'rIoN REGULATOR VALVE Arthur N. Kerr, Los Angeles, Calif., assignor to Phillips Petroleum Company, a corporation of Delaware 1 Claim. 1

This invention relates to hydrocarbon vaporizer systems. In one particular aspect it relates to small vaporizers adapted for preparing liquefied petroleum gases for combustion in household gas burners or similar service. In another particular aspect it relates to sensitive and fast acting pressure responsive means for intermittently admitting liquid hydrocarbons into a vaporization chamber. In still another aspect this invention relates to a pressure responsive valve for regulating fluid ilow. In still another aspect this invention relates to a valve for regulating iiow of iiuid therethrough in response to pressure of fluid at a source external to said valve.

This application is a division of my co-pending application, Serial No. 681,915, filed July 8, 1946, now U. S. Patent 2,516,218, issued July 25, 1950.

Liquened petroleum gases, such as commercial butane, are extensively sold for household fuel in regions not supplied by ordinary gas mains. Such liquefied gases must be vaporized before use in conventional gas burners. The methods of performing this vaporization may be divided into two general classes: a first class in which liquefied gases are allowed to Vaporize in a storage tank containing the liquid while gas is withdrawn for use from a vapor space above the liquid level in the storage tank, and a second class in `which quantities of liquid are withdrawn from the main body of liquid in a storage tank, either batchwise or continuously, and are vaporized in other equipment.

Vaporization of liquefied petroleum gases by methods of the first class is very unsatisfactory. Since it is not commercially feasible to sell a purified hydrocarbon as fuel, the products on the market, such as commercial butane, are mixtures of hydrocarbons having different volatilities. During the evaporation of such a mixture the hydrocarbons having lowest boiling points tend to evaporate first and the vapors rst evolved will contain a greater proportion of lowboiling materials, such as propane, than the residual liquid. As a result the B. t. u. value of the gas rst evolved is considerably different from that of the gas evolved later in the evaporation of a tankful of liquid. Such change in the heating value of the gas is very undesirable. Accompanying this change in heating value is a change in the proper ratio of gas to air necessary to secure eflicient combustion and burners must be adjusted frequently during the evaporation of a tank of liquid.

Methods of the second class mentioned above frequently employ a flash reduction of pressure to secure vaporization of the hydrocarbon liquid. Since heat of Vaporzation is absorbed in such flashing, there is a sharp reduction of temperature at the point where pressure is reduced. Minute traces of moisture are usually present in the hydrocarbon liquid and these tend to freeze upon and cause sticking of the pressure reducing valve.

In any method used for evaporating such hydrocarbon liquids, some means for supplying heat equivalent to the latent heat of vaporization must be employed. Steam, Water or hot gases formed by burning a portion of the evolved gases as taught by Martin 2,084,297 have been used. Such methods of evaporation are frequently uneconomical due to poor utilization of the heat applied, and the industry desires an evaporator which is economical in utilization of heat. Since such hydrocarbons are substantially completely vaporized at temperatures be- 10W 35 F., absorption of heat from the atmosphere or ground may also be used except in cold weather when such means are inadequate.

A small domestic vaporizer for evaporating hydrocarbon liquid withdrawn from such storage tanks in amount just suiiicent to maintain the desired range of gas pressure in lines leading to burners, which is not subject to operational difficulties due to freezing of pressure reduction valves and which is eihcient in utilization of heat is a greatly desired improvement in the art.

An object 0f this invention is to providey a pressure responsive valve for regulating fluid flow.

Another object is to provide a valve for regulating now of uid therethrough in response to pressure of iiuid at a source external to said valve.

Another object is to provide a novel pressure responsive valve mechanism suitable for controlling the quantity of liquefied petroleum gas admitted to a vaporizer.

Numerous other objects and advantages will be obvious to those skilled in the art upon reading the accompanying specification, claim and drawings.

Drawings In the accompanying drawings, Fig. 1 is an elevational View of a Vaporizer system embodying my invention with parts in section to show details of construction.

Fig. 2 is an elevational cross-sectional view of one form of motor valve which may be employed in the construction of motor valve I9 of Fig. 1.

Referring to Fig. l, a housing 6 encloses a hollow cylinder 1 of porous inert material, preferably carbon, leaving a space t, suitable for use as a reservoir of gas between the sides of the cylinder and walls of the housing. Annular sealing members 8 are disposed between the ends of cylinder 1 and adjacent walls of housing 6 in iiuidtight sealing relation with each. A tube II having an inlet I2 and an outlet I3 extends through housing 6 with its outer wall in gastight sealing relation with the walls of the housing. A thermostat actuated valve I4 is disposed in tube II and is adapted. to seat upon a valve seat I5, shown as integral with outlet tube I3, and thereby substantially close said outlet. Tube II is so disposed as to leave a small space I between the external surface of the tube and the internal surface of cylinder 1, which has an internal diameter substantially greater than the external diameter of tube II. One end of a pipe I1 is inserted into housing 9 communicating with space I6. The other end of pipe I1 is attached to the outlet of a snap-action, pressure responsive valve I9, constructed as shown in Fig. 2. The inlet of valve I9 is connected with line 2l leading to a source of liquefied gases. Line I3 provides free communication between pressure responsive means in valve I9 and gas under pressure in space 9. A pipe 22 is inserted into an upper portion of space 9 adapted to withdraw gas therefrom. A valved line 23 is insertedinto a lower portion of the same space for withdrawal of residual liquid.

Fig. 2 shows valve I9 in detail. A valve body 3l is provided with a passage 32 having an inlet 33 and an outlet 34. The inlet and outlet are adapted to be connected to piping. The valve body also has a cavity 3G, 31, 33, 39 of diversied cross section therein. A narrower portion 36 of this cavity communicates with passage 32 and a wider portion 31 of the cavity. An annular valve seat 4I is disposed in passage 32.

A exible diaphragm is disposed across cavity portion 31 in fluidtight sealing relation with the walls thereof. A valve stem 43 extends through this diaphragm and at its lower end is connected to a moveable valve head 44, adapted to be moved to seat upon valve seat 4I and thereby substantially close passage 32.

Adjacent to the upper end of valve stem 43 an annular supporting ring 46 is disposed in a still larger cavity portion 38. A spherically curved spring disc 41 is disposed in cavity portion 38 resting upon supporting ring 46. Disc 41 is adapted to curve upward, normally, and to be out of contact with valve stem 43, but upon being deformed under pressure beyond the point of being flat is adapted to spring into substantially equal and opposite curvature, as shown by the dotted line, striking the end of the valve stem a sharp blow and forcing the valve stem down to carry valve head 44 into position to seat on valve seat 4I thereby closing passage 32. Disc 41 is so constructed that upon release of pressure holding it down with a concave upper side it will spring or snap back into shape with a convex upper side. Such discs are old and well known in numerous devices.

A larg-e iieXible diaphragm 48 is installed across the largest cavity portion 39 in gastight contact with the Walls thereof. A thrust member 49 having a head 50 is attached to diaphragm 48 and is adapted to transmit pressure from said diaphragm to disc 41. A resilient member, shown as a coil spring 5I is disposed in cavity portion 39 adapted to resist downward motion of diaphragm 48 by predetermined force. That part of cavity portion 39 which lies above diaphragm 48 is cut off by the diaphragm to form gas chamber 152. Pipe I8 is inserted through a wall of this chamber and is adapted to establish free communication between this chamber and space 9 as shown in Fig. 1.

In some instances other means of providing snap action, such as levers and springs, may be employed, but for reasons of simplicity and sure operation I prefer to use disc 41.

Operation The apparatus shown in Fig. 1 is connected to a supply or" liquefied petroleum gas such as a storage tank via line 2| and to a source of warm water such as a domestic water line, via inlet pipe I2. Outlet pipe I3 may be connected to any means for utilizing chilled water desired or to waste in the absence of such use. Pipe 22 leads to burners of the type mentioned.

Starting with the thermostat controlled valve I4 in the open position as shown, warm water enters tube II until the temperature becomes high enough to cause valve I4 to close. When water contained in tube II becomes suiciently chilled. valve I4 opens and entering warm water forces chilled water out through outlet I3. Since water in passing through the tube II is not exposed to gases, outlet I3 may serve as an intermittent source for chilled drinking water, usually a very desirable advantage in isolated locations.

The vaporization cycle begins with valve I9 in open position. Liquefied petroleum gases flow from a source through line 2l, valve I9 and line I1 and enter the narrow space IB in liquid phase. Since the porous cylinder 1 offers considerable resistance to liquid iiow, the liquefied gases rise in space I6 and receive heat transmitted through the walls of ltube II. This results in boiling of the liquid with escape of gases through the porous cylinder into space 9. Liquid also seeps through the porous cylinder but suiiicient heat is transmitted by flow of fluid to vaporize such liquid.

Gas pressure builds up in space 9 and such pressure is communicated via line I8 and gas chamber 52 to diaphragm 48 in valve I9.

When such pressure becomes sufficient, diaphragm 48 transmits thrust through thrust member 49 and head 50 to cause disc 41 to snap into reverse curvature. This results in disc 41 striking the upper end of valve stem 43 a sharp blow, forcing the valve stem down and carrying valve head 44 to seat on valve seat 4| substantially closing passage 32 against the now of liquid.

Disc 41 is constructed to have internal forces therein which will automatically return it to the form of Fig. 2 upon release of pressure thereon beyond a predetermined point.

When pressure of gas in space 3 falls to a predetermined level, member 5I raises diaphragm 48 carrying thrust member' 49 and head 59 upward and disc 41 upon release of pressure to a predetermined level automatically snaps back into its original curvature; releasing pressure on valve stem 43. Leakage of liquid around valve head 44 due to pressure in line 32 then iills that portion of the body cavity -below diaphragm 42 and exerts pressure on this diaphragm, lifting valve head 44 from seat 4I. Full flow of liquid through valve I9 results.

Pipe 22 conducts gas from space 9 to the desired point for utilization. Since commercial liquid petroleum gases usually contain added odorants which are less volatile than the liqueed gases and may contain small amounts of heavy ends 'the valved pipe 23 is provided for occasionally withdrawing any liquid which may accumulate in space ii.

Advantages This vaporizer is very economical in use, eilicient in operation and easily serviced. All troubles caused by freezing of small quantities of water on the control valve mechanism 'are eliminated by the valve construction which provides all liquid contact with moving parts combined with a snap action movement in which the valve is closed by a sharp blow. This valve may easily be made responsive to small changes in pressure and `a constant pressure in chamber E? plus cr minus one-half pound per square inch is commercially obtainable. A gentle vaporization of liquid over a large surface is obtained by the unique construction or this vaporizer. Chilled water is obtained as a Icy-product. Collection of condensed heavy ends and odorants in house gas lines is avoided.

Many obvious changes in construction may be made by those skilled in the art Without departing from the spirit or substance of the invention which is defined by the subtended claim.

Having described my invention and explained its operation, I claim:

A snap action valve comprising in combination an elongated valve housing; a rst cavity in an end portion of said housing; a rst flexible diaphragm transversely closing said iirst cavity; a second cavity in said housing aligned with said first cavity, adjacent said rst cavity, and communicating therewith, and having a. smaller cross sectional area than said rst cavity; a third cavity in said housing aligned with said second cavity, adjacent said second cavity, and communieating therewith, and smaller in cross section than said second cavity; a second flexible diaphragm transversely closing said third cavity; a fourth cavity in said housing aligned with said third cavity, adjacent said third cavity, and communicating therewith, and smaller in cross sectional area than said third cavity; a rst conduit in an end wall portion of said housing opposite the above said end portion, terminating in cornmunication with a lowermost point in said fourth cavity, and extending to a point outside said housing; a second conduit in a side wall of said housing 'terminating in communication with an intermediate point in said fourth cavity and extending to a point outside said housing; a valve seat disposed in said first conduit at its end terminatingr in communication with said fourth cavity; a movable valve head disposed in said fourth cavity adapted to be moved to seat upon said valve seat and thereby transversely close said Iirst conduit; a valve stem attached to said valve head and extending through said second diaphragm; an annular support disposed in said second cavity; a spherically curved disc supported on said annular support adjacent to the end of said valve stem and normally curved away from said valve stem, said curved disc being positioned so as to permit movement of said valve stem and valve head away from said seat but adapted to snap under pressure into a substantially equal and opposite spherical curvature so as to strike said valve stem, whereby said valve stem carries said valve head to seat on said valve seat; a thrust member attached to said rst diaphragm, bearing a terminal rigid disc with raised edges adjacent to said curved disc, and adapted to transmit pressure from said irst diaphragm to said curved disc; means for resisting movement of said rst diaphragm toward said curved disc -by a predetermined force; and a conduit in the irst said end portion of said housing, in communication with an external source of uid pressure.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,919,265 Vaughn July 25, 1933 1,922,928 Cave Aug. 15, 1933 2,020,618 Persons Nov. 12, 1935

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