US1954930A - Valve fob fuel control - Google Patents

Description

Patented Apr. 17, 1934 UNITED STATES PATENT OFFICE VALVE FOB FUEL CONTROL Samuel Greenlee, Baltimore, Md.

Application March 5, 1930, Serial No. 433,224

8 Claims. (01.50-14) The object of my invention is to provide a regulating valve of simple, durable and trouble proof construction, for use in a place where instant response to change of pressure, however slight, is essential, such as control of combustion in furnaces of oil fired boilers.

A further object of my invention is to provide a valve construction which will eliminate the use of packing, piston rings, steam-tight or close sliding fits, or any sliding contacts which may offer frictional resistance to free movement of parts. A further object of my invention is to provide a valve in combination with the above which will 'not allow pressure on the outlet side to fall below a. certain predetermined point.

A further object of my invention is the providing of means of floating operating members in a valve to avoid friction.

A further object of my invention is an improved direct steam pressure control operating valve on the fuel supply system.

A further object of my invention is an improved direct steam pressure control operating valve on the fuel supply system, controlling the air supply for combustion.

A further object of my invention is an improved system of steam pressure control.

A further object of my invention is an improved direct steam pressure control operating valve on the fuel supply system controlling the fuel supply for combustion.

With the foregoing and other objects in view, my invention consists of the methods employed, combination and arrangement of systems, apparatus and means as hereinafter specifically set forth and illustrated in the accompanying drawings wherein is shown the preferred embodiment of my invention; but it is understood that changes, variations and modifications may be resorted to which come within the scope of the claims hereunto appended.

In the drawing of the herein described embodiment of my improved automatic control valve embodying the features of construction, and the arrangement and process involved in my invention, as a Specific illustration thereof, but which may be departed from in almost every detail; Fig. 1 is a diagrammatic view of my control system as installed in an oil burning steam plant of marine type, showing, particularly, the oil pump, control valves, and the air blower and control valves, and particularly described as follows:

A Scotch marine boiler 3 is shown connected by a steam pipe 4 to a fan and fan engine 5 for the normal requirement. The guide 24 on the supplying air pressure through air duct 6 to furnace 7, and a fuel service pump 8 provided to a suction line 9 to the fuel tank, not shown, and a discharge line 10 for supplying fuel under pressure to the burner 11. A by-pass valve 12 is for 0 use when full boiler pressure is required on the pump, or when the vessel is docking or maneuvering, and fuel pressure is being controlled by hand operation of throttle valve 13 on the pump 8. A throttle valve 14 is directly installed on the fan engine 5; two shut-off valves, 15 and 16, are installed on either side of my improved automatic control valve 17 and control the steam to the oil pump 8 and to the fan engine 5. Fig. 2 is an enlarged sectional view in elevation of my improved 7o automatic control valve 17.

Similar numerals refer to similar parts throughout the several views.

Referring particularly to my improved valve 17, shown in Fig. 2, the body 18 has an inlet 19 and an outlet 20. A spring casing 21 is flanged and secured to upper part of body 18 by bolts 22. Between the flanges of spring casing 21 and body 18 is secured a flexible metal diaphragm 23, and resting against the upper side of diaphragm 23 is a spring seat 24. This spring seat 24 is of suitable shape where it is in contact with diaphragm 23 to make said spring seat 24 self-centering, and is provided with flanges 24 which come in contact with spring casing 21 for the purpose of limiting upward travel of diaphragm 23 and to prevent distortion. Within spring case 21 and around spring seat 24, bearing against lower part of the same, is a spring 25 suitable for the steam pressure carried. In the upper part of spring casing 21 is an adjusting nut 26 for the purpose of varying the compression of spring 25. Passing through spring 25 and through the central part of adjusting nut 26, the spring seat 24 is extended to form a guide 24 A space recessed in the upper part of adjusting nut 26 contains a fiat ring 2'7 which has a slight chamfered clearance against guide 24 and a slight chamfered clearance against the outer part of the recess. This ring 2'1 has suflicient up-and-down clearance to 100 allow a canting motion which will permit spring Y seat guide 24 to travel about 1 6" before making a sliding contact with ring 27, one side of which it bears against. This travel is more than twice upper part of spring seat 24 is case-hardened to prevent a. ridge being formed.

The recess in the upper part of adjusting nut 26 is closed by cap 28, secured to adjusting nut 26 by screws 29. Between adjusting nut 26 and spring 25 is a. washer 30, seating into adjusting nut 26 for centering purposes, and between spring 25 and spring seat 24 is another washer 31.

Enclosed within body 18 is a valve 32 with extension, or valve stem 32 on the upper part, and on the lower part extension, or valve stem 32 to form guides. Valve stem 32 on the upper part of valve 32 is in contact with a pad 33, which provides a proper surface for contact with the under side of diaphragm 23. This pad 33 is flanged at 33 on the upper part for the purpose of limiting downward travel of the diaphragm 23 and to prevent distortion when steam is shut ofi.

In a recess under pad 33 is located a canting ring 34, similar to ring 2'7, for the purpose of holding valve stem 32 nearly central and operating in a similar manner to ring 2'7, as described, thereby keeping valve stem 32 in alignment without friction. A valve seat 35 is secured to body 18 and upon it seats valve 32. A cover plate 36 is secured to theunder side of body 18 by tap bolts 37; this cover plate 36 is recessed for the purpose of enclosing canting ring 38, similar in operation to-ring 27 and ring 34, herein before described, which acts as a guide for sub valve stem 32 Set into the lower part of bod; 18 and in contact with the cover plate 36 is a movable spring rest 39 which partially encloses valve spring 40. This valve spring 40 exerts pressure on the under side of valve 32. The amount of pressure exerted by this spring 40 can be closely adjusted by varying the thickness of adjusting washer 41. The pressure of spring 40 against the under side of valve 32 controls the point at which valve 32 will act independently of diaphragm 23 and maintain a predetermined minimum pressure on the outlet side. This is very important, because if the fuel pressure should fall too low, some or all'of the fires will go out and create a dangerous condition- The pressure at which this will happen depends upon the type of burner.

I will here briefly describe the operation of my invention as installed for the purpose of controlling combustion in the furnaces of oil fired marine boilers, thereby maintaining a steady steam pressure on boilers.

This is accomplished by the automatic variation of steam supply to fuel pump and fan engine. Inlet side 19 of valve casing 18 is in direct connection with the steam pressure on the boiler. Thus, full boiler pressure acts on the under side of diaphragm 23 through clearances around valve stem 32 and pad 33, and this pressure is balanced by the spring 25 under compression. Outlet 20 of valve casing 18 is in connection with the line supplying steam to the fuel pump 8 and steam to fan engine 5. Should the steam pressure on the boilers tend to fall the steam pressure on the outlet side of the valve will rise relatively, for the reason that spring 25 will tend to unseat valve 32 which will cause a more equalization of the steam between inlet 19 and outlet 20. When the main steam tends to rise, steam pressure on the outlet side of valve will fall, owing to the fact that the diaphragm will tend to raise or compress spring 25, permitting valve 32 to seat and cutting off the steam somewhat between inlet 19 and outlet 20, thus maintaining a balance. A variation of lb. on the inlet side will cause a variation of 4 lbs. on the outlet side, in a specific apparatus installed at sea, in the application of my invention. Under normal working conditions at sea, fuel pressures have been found to range about 2 lbs. either way from average. My invention prevents sufficient variation of main steam to visibly affect a high pressure steam gauge.

Throttle valve 13 on fuel pump 8 is carried wide open; throttle valve 14 on fan engine 5 is choked in, as usual to supply the proper amount of air. Any variation in fuel pressure is accompanied by a corresponding variation in air pressure, because both are supplied from the same steam line controlled by my valve; and this variation in air pressure will be exactly correct if a proper size throttle valve is used on the fan engine.

Working under this method the appearance of smoke will immediately advertise an improper condition of one or more fires.

The proper amount of air can be readily determined by adjusting air pressure to a point where with temperature and all other conditions remaining unchanged, fuel pressure is at its lowest, regardless of smoke. Fuel is then being burned to best advantage, and if too much smoke is present the cause should be found and remedied by some method other than increasing air pressure.

42 is a small tell-tale opening, or relief, in practice a hole about in diameter. This is for the purpose of allowing any steam that may pass, the diaphragm 23 to be observed at once. If the diaphragm 23 should become cracked or broken the natural effect would be to reduce the pressure thereon with the result that spring 25 would force valve 32 open and cause an abnormal main steam pressure, causing in the marine plant working close to the safety valve pressure a blowing of the safety valves, and would announce the cause by the steam coming out the tell-tale hole 42, which would be a broken diaphragm.

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

1. In a valve, means for floating the operative parts consisting of, a loose embracing member provided with a continuous circular edge embracing said parts and operating in an enlarged space whereby said embracing member may fulcrum on its edge.

2. In a valve means for floating an operative member comprising, a centering ring through which said member loosely operates, means for centering said ring comprising an edge guide therefor for permitting said ring to move bodily.

3. In a valve for controlling pressures a diaphragm operative to open and close a valve, a spring seat on the exterior of said diaphragm self-centering with reference thereto and provided with a stem for guiding purposes in combination with a spring surrounding said stem and means for adjusting the pressure thereof, said stem being centered by a contacting ring provided with a chamfered opening through which said stem operates and an enlarged chamber in which said ring loosely functions forming a guide for the periphery of said ring whereby said ring may move bodily and may tilt therein.

4. In a regulating valve provided with 2. diaphragm a pad operative between said diaphragm and a valve stem to give an extended surface against said diaphragm, a valve provided with a stem operative self-centering within said pad and loose means for centering said stem comprising a canting ring loosely surrounding the same operative within loose guides permitting the canting and motion thereof.

5. In a regulating valve provided with a diaphragm a pad operative between said diaphragm and a valve stem to give an extended surface against said diaphragm, a valve provided with a stem operative self-centering within said pad and loose means for centering said stem comprising a canting ring loosely surrounding the same operative within loose guides permitting the canting and motion thereof, and a sub-valve stem on said valve surrounded by a spring seat closing a spring operative to maintain said valve in closed position.

6. In a valve, means for floating the operative member, such as the valve with reference to its seat and which member is provided with guiding parts consisting of an embracing member loosely encircling said parts, this embracing member being a ring or endless roller and against one point on the inner edge of said ring the operative member may bear and roll, in a space sufllciently enlarged to permit the free tilting movement of the side of the ring opposite to that side against which the operating member happens to be hearing, constituting a roller bearing for the operative member.

7. In a valve for controlling pressures, a diapgragm shaped to centralize a contacting member s at operative to open and close a valve, a spring seat shaped to conform with and held central by said diaphragm, said spring seat having ample clearance space at the sides to avoid sliding contacts, said spring seat being provided with a stem in combination with a surrounding spring and means for adjusting pressure thereof, a loose embracing ring through which said stem passes, constituting a guide and roller bearing tor said stem. 8. A pressure regulating means having a single valve having two adjusting means, one of said means controlling the valve by the pressure on the inlet side of said valve admitting when the inlet pressure is below a predetermined point, the other of said means controll ng the valve by the pressure on the outlet sidie of said valve admitting when the outlet press e is below a predetermined point and loosely mounted tiltable bearing means for guiding said valve in its opening and closing movements, whereby gas or fluid is passed when the pressure on the inlet side of the valve is below a predetermined point, and also a gas or fluid is passed when the pressure on the outlet side of the valve is below a predetermined point.

SAMUEL GREENLEE.

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