US2304268A - Gas and air operated valve - Google Patents

Description

Dec. 8, 1942.

W. J. M GOLDRICK GAS AND AIR OPERATED VALVE Filed Feb. 12, 1940 finnenfor William "J. Mfioldrick Patented Dec. 8, 1942 I UNITED STATE S PATENT OFFICE Gas AND AIR OPERATED VALVE .William J. McGoldrick,

signor to Minneapoli Company, Minneapolis,

Delaware Minneapolis, Minn,, ass-Honeywell Regulator Minn., a corporation of Application February 12, 1940, Serial No. 318,419

4 10 Claims.

The present invention relates tothe operation and control of valves, particularly in gas fired combustion systems employing forced draft. In such systems diaphragm type gas control valves are commonly used and my invention deals primarily with a novel and improved arrangement for operating such a valve in the type of system referred to.

In the control of forced draft combustion systems employing gaseous fuel it is important that positive means be provided for actuating the fuel valve at the proper times and in the proper manner.

' It is the object of my invention to provide an arrangement offering assurance of the attain-" Another object of my invention is to provide an air operated diaphragm valve in combination with means providing for quick and positive closing of the valve.

Another object of my invention is to provide an air operated diaphragm valve in combination with means for applying gas pressure to one side of the diaphragm to assist in operation of the valve. v

The single flgure of'the drawing represents a gas fired forced draft combustion system embodying my invention therein.

Referring tothe drawing, numeral l designates a gas fired furnace of usual type there being located within the furnace a gas burner ll through which gas is supplied through a conduit l2. Interposed in the conduit I2 is a diaphragm type gas valve indicated generally at l3. Conduit l2 aheadof th valve [3 may communicate with any suitable source of fluid fuel such as gas. Located adjacent the burner H is a small pilot burner i4, the purpose of which is to ignite the flame of the main burner II and gas is continuously supplied to the pilot burner l4 by means of a tube I5 communicating with the conduit l2 ahead of the valve l3. Numeral l6 designates generally a safety pilot comprising a bimetal eleth flame of the pilot burner and flexed into engagement with a fixed electrical contact l8.

The furnace I0 is of a forced draft type, numeral 2| designating a forced draft fan driven by an electrical motor and having a discharge duct 22 communicating with the lower part of the furnace.

The body portion of the valve l3 has an inlet at 23 and an outlet at24, there being a passageway through the valve controlled by a valv member 25 to which is connected a valve stem 26. The

upper part of the valve l3 comprises a conically shaped portion 21 having a flange 28. Numeral 23 designates a dish shaped member having an opening in its lower portion, this member constituting the lower part of a diaphragm chamber of the valve. The peripheral portions of a sealoff diaphragm 3| are engaged between the flange 28 of portion 21 and the lower surface of the dish shaped member 29, these parts being secured together in any suitable manner. The valve stem 26 extends. through the seal-off diaphragm 3|, and the portions of the seal-off diaphragm adjacent'the valve stem are secured between a pair of collars 32 and 33 secured-to the valve stem in anysuitable manner. Numeral34 designates a ring shaped member of a size externally as great as the greater dimension or the flange'of the member 29. The ring 34 is superimposed on the flange of the member 29 with the peripheral portions ofthe diaphragm 35 secured between the ring 34 and the flang of the member 29. Numera1 36 designates a flanged cover element for the, diaphragm chamber having a flange of the same size as the ring 34, the flange being in en gagement therewith, the flanges, th ring 34 and the peripheral'portions of the diaphragm 35 all being secured together in any suitable manner. The valve stem 26 passes through the diaphragm 35 and the portions of the diaphragm adjacent the valve stem are secured between two discs 31 and 38 which are attached to the valve stem in any suitable manner.

Numeral 40 designates a three-way pilot valve of known type operated by an electric solenoid within the housing 4 I The three-way pilot valve comprises a body portion 42 having an opening 43 therewithin. A channel 44 in the body portion 42 communicates with the side of the opening 43 and a channel 45 in the body portion 42 communicates with the lower part of the opening 43 and form a seat for the valve member 46. The upper part of the opening 43 is closed by a plug 41 in screw threaded engagement with the ment I! located was to be normally heated by body portion 42 and having a central opening through which extends thestem 48 of the valve member 46. The space 43 is in open communication with an open space above the plug" through the opening in the plug around the -valve stem and the latter space communicates with the conduit |2 ahead ofthe valve |3 by means of the tube 49. The valvemember 46 is so shaped as to be able to close off communication through the channel 45 and the opening through the plug 41 also forms a valve seat so that the valve member 46 canbe moved upwardly to close off communication through the plug 41. When the solenoid within the housing 4| is deenergized the pilot valve is in the position shown. In

this position gas passes through the tube 49,-

through the plug 41 and channel 44 into the space above diaphragm 35, the pressure thus maintaining the valve l3 closed. When the solenoid within the housing 4| is energized the valve member 46 is moved upwardly so as to cut off communication of gas pressure through the plug 4|, and to release the gas from above the diaphragm 35 so that it can pass through the channels 44 and 45. The channel communicates with an auxiliary. pilot burner-50 by means of atube5l.

, thermostat which may be of a well known..type='comprising a bimetal element 53 having a movable switch blade 54 attached thereto,-the switch blade'54 cooperatingwith a fixed electrical contact 55. Upon a drop'in-temp'erature to which the thermostat 52 is responsive, to a predetermined value the blade 54 engages-with the contact 55.

In operation, whenever the thermostat 52 makes'contact as described, a circuit is completed for the draftfan as follows: from wire 60 through the safety pilot I6, wire 6|, thermostatic element 53, blade 54; contact 55, wire 62, wire 63, the fan motor, wire 64 and, wire 65, the wires 60 and 65 being connected to any suitable line conductors. At-the same time a circuit is completed for the solenoid within housing 4| as follows: from wire 60 to safety pilot l6, wire 6|,

thermostatic element 53, blade 54, contact 55,

wire .62, wire 66, the solenoid within housing 4| back to wire'65. As soon as these circuits are completed the draft fan starts in operation and the valve member 46 is moved to its upper position to release the gas from diaphragm 35 as above described. As soon as an appreciable amount of pressure-has been built up in discharge duct 22 this airpressure is communicated to the chamber on the lower side of diaphragm 35 through tube 39 and the diaphragm 35 is lifted ina' manner to open the valve l3. As soon as the valve is open gas is supplied to the burner II and heating commences, and continues as long asthe thermostat 52 is calling for heat. When the thermostat becomes satisfied the above traced circuits are interrupted, the fan stops and the pilot valve 40 assumes the position shown on the drawing. Inasmuch as the fan and its driving motor have a certain amount of momentum the fan does not stop as soon as its motor is deenergized and therefore the pressure in discharge duct 22 does not immediately disappear. Therefore, without other means cooperating to close the valve l3 it would be delayed in 1 its closing" action until the pressure had dropped sufliciently within the duct 22 and the chamber below the diaphragm 35. To avoid-this condition and in order to bring about quick and positive closing of the valve thethree-way pilot valve 40 is provided to permit gas pressure to be applied to the upper side of the diaphragm 35 as soon as the fan motor is deenergized in order to force the diaphragm downward. Thus whenever the fan motor is deenergized the three-way valve assumes the position shown on the draw- -ing and gas pressure passes through the tubes 49, the opening in plug 41, space 43 and channel 44 into the chamber about diaphragm 39. The pressure acting on the upper side of diaphragm 35 quickly closes the valve preventing any de layed action which would otherwise take place.

From the foregoing those skilled in the art will appreciate that I have provided an eflicient and positive acting arrangement whereby a diaphragm valve may be operated by means of a draft pressure from a draft fan, and wherein the valve will be operated with the desired quick movements by reason of the arrangement for causing gas pressure to act on the upper side of the diaphragm for closing.

The single embodiment of my invention which I have disclosed is representative and the scope of the invention is to be determined not in accordance with my disclosure but only by the scope of the appended claims.

I claim as my invention:

1. In a heating system, in combination, com.- bustion means comprising a furnace having forced draft means, -fuelsupply means including a diaphragm type valve having a diaphragm in a diaphragm chamber, means for exposing one side of said diaphragm to draft air pressure for opening the valve. and means for exposing the other side of the diaphragm to fuel at substantially supply pressure, said fuel pressure supplying the power for closing the valve and maintaining it in closed position, said last means including means for releasing fuel pressure from said other side of the diaphragmto permit the valve to be opened by the draft air pressure.

2. In a gas fired heating system, in combination, a furnace, forced draft means and gas supply control means including a gas valve having a diaphragm located within a diaphragm chamber, means for conveying air pressure from said forced draft means to said diaphragm chamber for moving said diaphragm in one direction, pilot valve means controlling the admission to and release of gas from the chamber on the opposite side of the diaphragm and control means for starting the forced draft means in operation and at substantially the same time operating said pilot valve .meansto cause gas to be released from said diaphragm chamber.

3. In a gas fired combustion system, in combination, control means comprising a. valve having a diaphragm chamber with a diaphragm dividing the chamber into two parts, forced draft means, means for conveying draft air to the space on one side of the diaphragm for opening the valve, means comprising a pilot valve for admitting gas pressure to and releasing gas from the space on the other side of the diaphragm; and thermostatic means controlling the forced draft means and said pilot valve means to substantially simultaneously energize said forced draft means and actuate said pilot valve means to release gas from the spaceon the other side of said diaphragm.

4. In a gas fired heating system, in combination, a furnace, forced draft means and gas supply control means including a gas valve having a diaphragm located within a diaphragm chamber, means conveying gas pressure to one side of said diaphragm urging said valve in closing direction, means for cutting off the supply of gas to said one side of the diaphragm and releasing the pressure acting thereagainst, and means conveying draft air from the discharge side of said forced draft means to the other side of said diaphragm for opening said valve whereby said valve is not opened until after the establishment of draft.

5. In a gas fired heating system, in combination, a furnace, forced draft means and gas supply control means including a gas valve having a diaphragm located within a diaphragm chamber, means comprising a three-way pilot valve for admitting pressure to and releasing pressure from one side of the diaphragm, means for conveying draft air from the discharge side of said forced draft means to the other side of said diaphragm for opening said valve, and means comprising a thermostat controlling said forced draft means and three-Way pilot valve to substantially simultaneously energize said forced draft means and actuate said pilot valve to release pressure from said one side of said diaphragm.

6. A fuel control device comprising in combination, a combustion chamber, a conduit for conveying fuel to said combustion chamber, a valve in said conduit for controlling the flow of fuel, a forced draft means for supplying com bustion supporting air to said combustion chamber, means, controlling said valve comprising a diaphragm and a pair of diaphragm chambers, means for subjecting one of said chambers to pressure for closing said valve and for relieving said pressure when it is desired to open said valve, and means connecting the other chamber with the pressure created by said forced draft means for opening said valve.

'7. A fuel control device comprising in combination a combustion chamber, a conduit for conveying fuel to said combustion chamber, a valve in said conduit for controlling the flow of fuel, a forced draft means for supplying combustion supporting air to said combustion chamber, means controlling said valve comprising a diaphragm and a pair of diaphragm chambers, means for alternately subjecting one of said chambers to pressure and venting it to atmosphere, said diaphragm tending to move said valve to closed position when said one chamber is subjected to pressure, means connecting said other chamber to the downstream side of said forced draft means whereby said valve may be opened only if said forced draft means is operative, and means for substantially simultaneously venting said one chamber to atmosphere and rendering said forced draft means operative.

8. A gas burner control system comprising in combination, a gas supply conduit for delivering gas under pressure to a burner, forced draft means for supplying combustion supporting air,

a valve in said gas supply conduit controlling the flow of gas therethrough, means for actuating said valve including a diaphragm and first and second diaphragm chambers, control means for alternately connecting said first chamber to the pressure of gas from the upstream side of said valve for closing said valve and venting said chamber, means connecting said second chamber to the downstream side of said forced draft means for opening said valve, and means responsive to a demand for heat for venting said first chamber and energizing said forced draft means whereby the pressure developed by said forced draft means opens said valve.

9. A gas burner control system comprising in combination, a gas supply conduit for delivering gas under pressure to a burner, forced draft means for supplying combustion supporting air, a valve in said gas supply conduit controlling the flow of gas therethrough, means for actuating said valve including a diaphragm and first and second diaphragm chambers, a valve stem connecting said diaphragm and valve, a second diaphragm connected to said valve stem and sealing said second chamber from the gas pressure at said valve, control means for alternately connecting said first chamber to the pressure of gas from the upstream side of said valve for closing said valve and venting said chamber, means connecting said second chamber to the downstream side of said forced draft means, for opening said valve and means responsive to a demand for heat for venting said first chamber and energizing said forced draft means whereby the, pressure developed by said forced draft means opens said valve.

10; In a gas fired heating system in combination, a gas valve for controlling the supply of gas to a burner, a diaphragm located within a diaphragm chamber for moving said valve between open and closed positions, pilot valve means for controlling the admission of gas to one side of said diaphragm for closing said gas valve when there is no demand for burner operation and for bleeding said gas pressure in response to a demand for burner operation, means preventing the pressure of said gas from opening said gas valve, and means for admitting air under pressure from a forced draft means to said other side of said diaphragm for causing opening of said gas valve when said pilot valve means is in a position to bleed gas from said one side of said diaphragm and said forced draft means is in operation.

WILLIAM J. MCGOLDRICK.

Images