US2284910A

US2284910A - Flow control system for gas burners

Info

Publication number: US2284910A
Application number: US253261A
Authority: US
Inventors: Herbert J Long
Original assignee: Individual
Current assignee: Individual
Priority date: 1939-01-28
Filing date: 1939-01-28
Publication date: 1942-06-02
Anticipated expiration: 1959-06-02

Description

June 2, 1942. H L LONG 2,284,910

FLOW CONTROL SYSTEM FOR GAS BURNERS Y Filed Jan. 28, 1939 ATTORN Patented June 2, 1942 FLW CONTROL SYSTEM FOR GAS BURNERS Herbert J. Long, Springfield, Mass.

Application January 28, 1939, Serial No. 253,261

3 Claims.

This invention relates to a now-controlled valve for instantaneous water heaters. 1

In water heaters of the type to which the invention relates it is common practice to control the ow of gas or other fuel to a burner by the pressure of the water in the system. Such devices have been of two general types, one of which comprises a cylinder Within which reciprocates a close fitting piston. The cylinder is provided with an opening at one end for admitting water and an outlet opening' or port in the side of the cylinder to discharge water. A spring acting upon the piston tends to oppose the pressure upon the intake side thereof. The inlet port is connected tothe house supply system and the outlet port is connected to aV faucet by way of the coils or other heating element of the heater. A stem attached to the piston and extending outwardly through'a stuffing `box in the end wall of the cylinder is adapted to actuate the stem of a gas valve so thatwhen a hot water faucet is opened the drop in pressure at the outlet port causes the piston to be moved forward by the action of the pressure of the water on the inlet side of the piston, this movement proceeding until the piston has uncovered the outlet port sufciently to allow the flow of water required by the faucet opening. When the faucet is closed the pressure upon the two sides of the piston becomes equalized and the piston is returned to its original position under the action of its spring while the gas valve is returned to its seat under the action of its spring.

Flow controlled devices of the type described have many defects. Under relatively high water pressures the leakage at the stuffing box is a constant source of dimculty. The Wear between the piston and cylinder under the action of water having considerable sediment Causes wear which in time permits a leakage around the piston so great that when a faucet is opened the Water may flow around the piston without moving the same to an extent sufficient to actuate the gas valve. Water hammer, a reaction due to the operation of other faucets, such as ani7 rocating piston. One side of the diaphragm is acted upon by the full pressure of the water supply line, and the other side of the diaphragm is acted upon by the pressure at the throat of a venturi in the line. When water flows at sufficient velocity through the venturi there is a pressure drop at the throat with the result that the diaphragm fiexes under the influence of the differential pressure and the gas valve is pushed open by means of a stem connected to the diaphragm. This type of valve is subjectk tothe same difficulties which Were mentioned in connection with the piston type of valve in that the stuffing box is subject to leakage, the valve may stick in :open position due to the sticking of the stem in the stuffing box and furthermore, the passages connecting the throat of the venturi with one side vof the diaphragm may become clogged thus preventing proper operation.

It is the primary object of the present invention to overc-ome the above mentioned diiculties by eliminating the stuiiingbox and any other relatively movable parts which are likely to stick when the valve is in open position.

A further object of the invention is to provide a control device depending upon the flow of water through the system rather than on the panying drawing in which Fig. 1 illustrates a cold water faucet, on the same line causes a momentary operation of theA piston and accordingly momentarily opens the gas valve and Wastes fuel. The piston may stick in open position due to foreign matter in the Water with consequent danger of overheating the system and ruining the heating elements, if not causing other damage due to the formation of steam.

The second type of water pressure valve utilizes a rubber diaphragm instead of the reciplongitudinal section through the control device and associated elements, parts being Vshown in side elevation; and Fig. 2 is a detail of a portion of the control device with parts shown in section and parts in side elevation.

Referring to the drawing reference numeral I indicates a T fitting having an externally threaded portion 2, adapted to be connected to a source of water supply, and an internally threaded portion 3 adapted to be connected to a line leading to one or more hot water faucets. It will be understood that a heating element not shown is provided in the connections leading tothe device or in the line between the device and the faucet as desired. A partition 4 having an opening 5 divides the T l in such a manner as to form a nozzle directed toward a vane 6 positioned adjacent the discharge side of the oririce 5. The vane 6 is supported by a stem 'I which extends through `a leg 3 of the T fitting I at right angles to the intake and discharge connections 2 and 3. A block 9 which is attached by screws i@ to the leg B closes the open end of leg B except for an opening II through which the stem 7 extends. The block 9 is provided with an annular boss I2 surrounding the opening I I to which boss one end of a metal bellows I3 is integrally attached by brazing or welding. The opposite end of the bellows I3 is closed by a head ill integrally attached to the bellows, which block is provided with an inwardly projecting portion l5 of reduced diameter. The outer end of the stem i ts tightly or is screw threaded into a bore which extends centrally for a short distance into the portion I5. The head I4 is also provided with an outwardly extending portion it which'projects through a central opening in thimble I'I and is screw-threaded to accommodate a lock nut EB. A pair of brackets I9 are attached to the block 9 by screws 20 and carry, at their outer ends, a pair of pivot screws 2 E. The pivot screws 2i project into openings 22 in the side wall of the thim-ble Yil to pivotally mount said thimble and the portions attached thereto in such a manner that the stern I of the vane 6 is capable of swinging through a small arc to permit motion of the vane 5 toward and away from nozzle opening 5.

Mounted adjacent to the T l by means of a bracket 23 is an elbow 2li forming a housing for a gas valve `25, the stem 2t of which is biased upwardly by-a spring 2l to a position adjacent an adjustable contact screw 2% in the projecting end I6 of block i4.

In the operation of the device as above described, it will be understood that .when the parts are in the position shown, no water is being drawn through the system. Upon the opening of a hot wat-er faucet, there is a reduction in pressure upon the discharge side of the nozzle opening 5. If the opening is material, that is more than caused by a mere leak or drip at the faucet, then the water from the intake-side of the device flows with considerable velocity through the orifice 5 and against the vane The vane is thereby forced away from the nozzle opening 5 and this motion is transmitted by the stem 'I through the pivoted head I4 of the bellows and the projecting portion I5 to move the valve stem 26 downwardly and open the valve 2&5. Gas will thereupon ow through the openingi and it will be understood that this gas flow may constitute the entire gas supply to the main burner or may constitute a portion of the gas supply in a manner to actuate the main gas valve of the burner as described in my copending application Serial No. 253,262, filed January 28, 1939.

In either event, the opening of the valve 25 initiates the flow of gas to the burner of a conventional type of instantaneous water heater. -It will be observed that in pivoting upon an axis formed by the screws 2I, Vthe bellows I3 is distorted laterally, such distortion being permissible in view of the reduction in pressure on the discharge side of the nozzle opening 5. When the hot water faucet is again closed, the flow through the opening 5 ceases and the vane 6 returns to its original position due in part to the action of spring 2l and in part to the fact that the lateral distortion of the bellows I3 is opposed by the pressure in the system. The bellows therefore tends to return to its normal position upon the increase in pressure which follows upon the closure of the hot water faucet.

Although but one embodiment of the invention has been set forth in the above description, other embodiments within the scope of the appended claims will be obvious to those skilled in the art.

Having thus described the invention, L claim:

1. A flow-controlled device for instantaneous water heaters including a member forming a portion of a water supply line, a vane within said member movable in response to the ow of water through said line, a stem attached to said vane and projecting outwardly through an opening in said member, a bellows surrounding said opening and attached at one end to said member and at its opposite end to said stein, the interior of said bellows being subjected to the pressure in said line, means to prevent longitudinal distortion of said bellows while permitting lateral distortion thereof in response to movements of said vane, and a gas Valve actuated by forces transmitted thereto from said vane through lateral distortion of said bellows to control the flow of fuel to a burner of said heater.

2. A flow-controlled device for instantaneous water heaters including a member forming a portion of a water supply line, a vane within said member movable in response to the ow of water through said line, a stem attached to said vane and projecting outwardly through an opening in said member, a bellows surrounding said opening and attached at one end to said member and at its opposite end to said stem, the interior of said bellows being subjected to the pressure in said line, a bracket mounted on said member, a thimble rigidly iixed to the outer end of said bellows and extending along a portion of the length thereof, means for pivotally securing said thirnble to said bracket at a point intermediate the length of said bellows, whereby longitudinal distortion of said bellowsis prevented while lateral distortion is permitted, and a gas valve actuated by forces transmitted thereto from said vane through lateral distortion of said bellows to control 'the ow of fuel to a burner of said heater. n

3. A flow-controlled device including a water supply line, a Vane pivotally mounted for movement in the direction of flow through said line, a partition in said line in front of said vane, said partition having an orifice adjacent a face of said Vane, a stem for said vane projecting through an opening in said line, a bellows forming a fluidetight joint surrounding said opening and having Va head at its opposite end, the interior of said bellows being subjected to the pressure'in said line, means to prevent longitudinal distortion of said bellows while permitting lateral distortion thereof, whereby the flow of water through said line upon the opening of a faucet tends to move said vane away from said orifice to distort said bellows laterally andthe pressure of water in said line tends to return said vane to its original position upon closure of a faucet.

HERBERT YJ. LONG.