US3917162A - Diaphragm valve for controlling supply of gas to water heater - Google Patents

Abstract

Valve for controlling flow of gas to water heater comprises two chambers separated by a diaphragm. A first chamber has a gas inlet and a gas outlet leading to the burner of the heater. The outlet is controlled by the diaphragm position which is in turn dependent on the relative pressure in the chambers. A by-pass connects the two chambers, and the diaphragm position is therefore dependent on the exhaust from the second chamber, which is controlled in response to the flow of water to the heater and the temperature of the water.

Description

Umted States Patent 11 1 1111 3,917,162

Trotter et al. Nov. 4, 1975 1 DIAPHRAGM VALVE FOR CONTROLLING 3,426,971 2/1969 Meier 236/23 x SUPPLY OF GAS TO WATER HEATER Primary ExaminerWi1liam E. Wayner [76] Inventors g ag z gggghg z gggz ghgg Assistant ExaminerWilliam E. Tapolcai, Jr.

Santiago Chile Attorney, Agent, or FirmBrisebois & Kruger 221 Filed: Nov. 22, 1914 [57] ABSTRACT PP 526,211 Valve for controlling flow of gas to water heater comprises two chambers separated by a diaphragm. A first chamber has a gas inlet and a gas outlet leading to the 81. 23622192,B1;Z8M7) burner of the heater. The outlet is controlled y the [58] Field sE E 137/87 diaphragm position which is in turn dependent on the ii relative pressure in the chambers. A by-pass connects the two chambers, and the diaphragm position is [56] References Cited therefore dependent on the exhaust from the second UNITED STATES PATENTS chamber, which is controlled in response to the flow 1,878,270 9/1932 Eberspacher 236/25 of wat r to the heater and the temperature of the wa- 2,009,193 7/1935 Hegwein et al.... 236/25 ten 2,848,167 8/1958 Matthews 236/23 X 3,118,600 l/1964 Miller 236/23 8 Claims, 1 Drawing Figure US. Patent Nov. 4, 1975 3,917,162

DIAPHRAGM VALVE FOR CONTROLLING SUPPLY OF'GAS TO WATER HEATER .sUM MARY OF THE INVENTION The object ofthe present invention is to improve the magnetic-mechanical valves or devices employed for the control of the gas flow in instantaneous water heaters, as disclosed in US. Pat. No. 3,806,026, dated Apr. 23, 1974.

The devices disclosed in said patent represented a substantial 'improvementand novelty in the field of the gas flow control devices for water heaters because by the use of a novel magnetic device comprising a hollow magnetic piston and a set of permanent magnets mounted on the arms of a tilting lever, the invention provided for both the progressive lighting of the water heater burner and the instantaneous cut-off of said burner in the event no water is flowing.

In addition to the above mentioned feature, a novel thermostatic device provided a constant modulationof the burner flame, at the users option, as a function of the water flow, preventing the over-heating of the heat-exchanger coil, and eliminating all the problems usually encountered in conventional water heaters.

Practical use has shown that despite the fact that the system disclosed in said U.S. Pat. No. 3,806,026 is sufficiently efficient to serve all the above purposes, the

additional modification and improvements according to the present invention provide a simpler system which operates more satisfactorily and costs less to manufacture.

Fundamentally, the improved device which is the object of the present invention comprises a novel assembly of magnetic elements controlling the opening or closing of a diaphragm type main gas valve, which can be regulated through its entire opening range by means of a novel thermostatic control system.

To additionally provide a high degree of safety, the improved valve according to the invention is provided with a failsafe system, using a thermocouple (which is not in itself the object of this invention) which in turn controls a magnetic coil that prevents the lighting of the main burner in the event the pilot-flame"is not lighted.

The following is a description, as an illustrative example, of apreferred embodiment of the present invention, with reference to the accompanying drawing which is a side elevation of the system with the magnetic device and the improved diaphragm valve shown in section. I

As illustrated in the FIGURE at the left side of the drawing there is a hollow metal body 1 connected at its two ends to the inlet andoutlet ducts 2 and 3 through which the water to be heated in the heat-exchanger coil 4 of the instantaneous water heater circulates.

Inside the hollow body l arestop rings 5 and 6 limiting the axial movemen t' of the hollow piston 7, which is formed by a permanent magnet.

As disclosed in US. Pat. No. 3,806,026, the magnetic hollow piston 7 moves upwardly or downwardly inside the body 1 in dependence on the flow of water through theducts 2 and 3. When the flow increases, the magnetic piston 7 will move upwardly until it abuts against the stop ring 6, and, conversely, the piston 7 will move downwardly when the flow decreases until it is seated on thebottom ring 5 when the flow stops.

The broken lines show the piston 7 at its bottom position when there is no flow induct 2, and the solid lines show said piston in its upper position when the water is flowing.

A second, short, hollow metal body 8 projects from the center part of the hollow metal body 1, at a right angle relative to the geometrical axis of the body 1. The body 8 has inlet andoutlet nozzles 9 and 10 respectively for discharging the gas flow from the diaphragm valve.

Inside the hollow body 8 is a solid magnetic piston 11 having its North pole facing the North pole of the magnetic piston 7, across the wall of the body 1 when the piston 7 is at its bottom position.

The other end of the piston 11 (i.e., its South pole) is provided with anelastic disc 12 made of rubber, neoprene or the like, the position of which permits or prevents the flow of the gas through thenozzles 9 and 10. Thenozzle 10 projects into the body 8 forming a seat 13 for theresilient disc 12 and providing a gas-tight seal when the magnetic piston 11 is remote from the magnetic hollow piston 7 due to the magnetic repulsion produced when the North poles of both magnets 7 and 11 are facing each other.

This assembly which is controlled by the fluctuations in the stream of water flowing through the instantaneous water heater, which fluctuations are produced by the user or being caused by variations in flow in the water mains, controls a diaphragmtype gas valve 14, which in turn controls the gas feed to theburner 15.

Thediaphragm valve 14 comprises anupper chamber 16 and alower chamber 17, separated by adiaphragm 18 made of a resilient material, said diaphragm having in its center aclosure disc 19 made of metallic or resilient material. The gas inlet 20 opens into theupper chamber 16 which has in one wall theseat 21 for theclosure disc 19 of thediaphragm 18. Between the gas inlet 20 and the seat ornozzle 21 is aclosure valve 22 biased closed by a spring but held open by asolenoid 23 activated by athermoelectric device 24 responsive to thepilot flame 25 when that flame is lit. In

the upper part of thevalve body 14 is located theconical gas valve 26 defining a duct ororifice 27 leading to thepilot flame 25..

The stem and body of theconical valve 26 are axially perforated to accommodate a pin 28 ending in aknob 29. The pin 28 is biassed by thehelical spring 30 away from theclosure valve 22 which, when seated on seat 22a, interrupts the gas flow. To initially permit the flow of gas to thepilot 25 it is necessary to press theknob 29 inward, and this can be done only when theconical valve 26 is closed, because of the half 29a of said knob which must be introduced in a corresponding slot in theknob 29b of theconical valve 26. In thelower valve chamber 17 is a novel ignition retarding valve comprising a box 31 havingorifices 32 in its upper part. Inside the box 31 is asmall disc 33, made of metal or other material, having at least one small orifice 34 therein.

Thelower chamber 17 and theupper chamber 16 of the diaphragm valve are connected by a duct 35 connected to aduct 36 which in turn connects the ignition retarding valve 31 with the perforated pin 37 of thetemperature regulator 38 located in the lower part of thevalve 14.

The temperature regulator 38a comprises a threadedportion 39 adapted to be rotated by theknob 38 to permit the forward or backward movement of the perforated pin 37 relative to the conical end 40 of thethermostat 41 which is connected to thecapillary tube 42 connected to abulb 43 suitably immersed in the heatexchanger coil 4 of the instantaneous water heater in order to sense the water temperature.

Theduct 36 in thelower body 17 of the diaphragm valve leads to aduct 44 which receives a regulatingscrew 45 to regulate the minimum flame.

Theduct 44 is connected to theoutlet nozzle 46 which is also connected to thechamber 47 containing the conical end 40 of the thermostat and the end of the perforated body 37 of the temperature regulator.

Theoutlet nozzle 46 is connected to the nozzle 9 of the hollow body 8 through aduct 48 having a small diameter, and theoutlet nozzle 10 of the body 8 is connected to theconical valve 26 through atube 49 likewise having a small diameter.

in operation, the control valve assembly according to this invention operates as follows:

a. When thevalve 22 is opened, by depressing theknob 29 to ignite the pilot, the combustible gas enters thediaphragm valve 14 through the gas inlet 20, thus filling theupper chamber 16, and flows through the duct 35 toduct 36 and thence through the ignition retarding valve 31 to fill thelower chamber 17.

b. When the flow of water to the water heater is inter rupted, the hollow magnetic piston 7 is on its bottom position and the repulsion between the North pole of the magnet 7 and the North pole of the magnetic piston 11 urges theclosure disc 12 against its seat 13, preventing gas flow between thelower chamber 17 of thediaphragm valve 14 and theducts 48, 49 to theburner 15.

c. When the seat 13 is covered by theclosure disc 12 of the magnetic piston 11, the pressure in thelower chamber 17 and theupper chamber 16 is equalized and the spring forces thediaphragm 18 and theclosure disc 19 to seat against theseat 21, interrupting gas flow to theburner 15 from theupper chamber 16.

d. When a predetermined stream of water flows through the hollow body 1, the hollow magnetic piston 7 moves from itsbottom position 5 to its upper position 6, and the South pole of the magnetic piston 7 faces the North pole of the magnet 11 located in the hollow metal body 8, thus producing a magnetic attraction and withdraws the closure disc 12 (attached to the South pole of said magnet 11) from its seat 13 permitting communication between the gas nozzles 9 and and permitting the exhaust of the gas accumulated in the lower chamber17 of thediaphragm valve 14, which gas flows through theducts 48 and 49 to the main heater of theburner 15, if and when theconical valve 26 is in its open position.

c. On the other hand, due to this gas exhaustion a pressure reduction is produced in thelower chamber 17 relative to the pressure in theupper chamber 16, so that thediaphragm 18 moves downward to open theseat 21 and allow the flow of gas to theburner 15.

When thelower chamber 17 is connected to the burner through theconical valve 26, a gas exhaust is produced and thedisc 33 is seated against the seat at the end of theduct 36 and the gas accumulated in thelower chamber 17 is slowly released through the small diameter orifice 34 of thedisc 33.

f. The slow release of the accumulated gas permits thediaphragm 18 to gradually uncover the opening of theduct 21, so that the ignition of theburner 15 is pro duced slowly as thelower chamber 17 of the diaphragm valve is emptied, thus preventing the sudden ignition of the burner. This is advantageous because there is no sooting of the burner and no detonation noise.

g. When the water flow through theduct 2 decreases for any reason, or if said flow is completely interrupted, the hollow magnetic piston 7 descends to its bottom position, and the magnetic attraction exerted on the magnetic piston 11 is replaced by a magnetic repulsion that reaches its maximum intensity when the magnetic piston 7 is at its lowermost position.

The movement of the magnetic piston 11, in dependence on the water flow variations controls the passage of the gas between thenozzles 9 and 10 thus controlling the passage of gas to theburner 15, because when the flow of gas from the lower chamber through theduct 48 is interrupted, the gas pressure will be equalized inside bothchambers 16 and 17, forcing the rapid movement of the diaphragm to close theinlet 21 and interrupting the gas flow to theburner 15.

A description of the operation of the thermostatic water temperature control of the instantaneous water heater follows:

Thesensor bulb 43 senses the water temperature in a suitable part of the coil 4 and the consequent increase or decrease in the volume of the liquid or gaseous medium inside thebulb 43 andcapillary tube 42 controls the movement of the conical end 40 of the thermostatic bellows 41, which is attached to the bottom part of the diaphragm valve. This conical end 40 movesforward or backward relative to the perforated pin 37 that forms part of thetemperature setting knob 38, which is suitably graduated for the convenience of the user.

When the temperature setting is increased (by the counterclockwise turning of said knob 38) the threadedportion 39 determines the position of the perforated pin 37 and the conical end 40 of the thermostat is forced to travel further before seating on the mouth of said perforated pin 37; i

As the conical end 40 moves toward the open end of i said perforated pin 37 (due to an increase in the temperature of the water sensed by the sensor bulb 43) the gas flow from theupper chamber 16 and thelower chamber 17, through theducts 35, 36, 48 and thenozzles 9 and 10 is restricted, thus producing a pressure increase in thebottom chamber 17 which controls the movement of theelastic diaphragm 18 and the respective restriction of the gas flow to theburner 15,produ cing a quick reduction of the water temperature in the heating coil 4 and theoutlet pipe 51.

The water temperature reduction is sensed by thebulb 43 and the respective reaction of the thermostatic means is to retract the conical end 40 removing said end from the perforated pin 37, allowing a larger flow of gas through thechamber 47 and reducing the .pressure in thebottom chamber 17, thus allowing the opening of the diaphragm, due to pressure in theupper chamber 16, and increasing the gas flow to theburner 15, which in turn causes the water temperature to increase until the high water temperature causes the restriction of the gas flow to thechamber 47 and the reduction of the gas flow to theburner 15. The above mentioned cycle is repeated again and again while the water heater is in operation and the response (reaction time to the temperature changes) is' so fast and accurate that it has been found under operating conditions the temperature of the outlet water is constant through the entire range of the system (from 30 to 60C).

lt must be noted that even if the conical end 40 of the thermostat fully closes the outlet of the gas exhausted through the perforated pin 37, the burner is not totally turned off because a minimal amount of gas keeps flowing from the duct 35 to theducts 36 and 48 through the small diameter orifices 37a of the perforated pin 37 so as to maintain a small pressure differential between theupper chamber 16 and thebottom chamber 17 of the diaphragm valve, thus allowing a small gas flow from inlet 20 to theburner 15.

The volume of this small gas flow (which produces a A minimum flame) can be easily regulated by adjusting the setting of theminimum flame screw 45 to decrease or increase the flow of the gas drainage from the upper to the bottom chamber of the diaphragm valve.

It is interesting to note that the improved control device disclosed in this description does not require mechanical linkages to interconnect the component parts of the device, thus eliminating the usual problems encountered in conventional control systems, such as stuck pins, bent levers, rusted pins or levers, damaged seals producing water and/or gas leaks, and so on; because there is no physical connection or communication between the gas and water circuit portions.

It is also necessary to keep in mind that the device according to the present invention may be modified as to detail so as to adapt this novel control device to an economical manufacturing process, without departing from the spirit and scope of invention as claimed in the following claims.

What is claimed is:

1. In a diaphragm valve for controlling the flow of gas to a water heater'including a burner and equipped with a magnetic member responsive to variations in the flow of water to said heater, said valve comprising first and second chambers separated by a diaphragm, said first chamber being provided with a gas inlet and an outlet leading to said burner, and said diaphragm being movable between a first position closing said outlet and a second position in which said outlet is left open in dependence on the relative pressure in said chambers, the improvement which comprises duct means connecting said first and second chambers, and providing an exhaust for said second chamber,

magnetically actuated valve means responsive to the position of said magnetic member and positioned to control the exhaust of gas from said second chamber through said duct means, and

manually adjustable heat responsive valve means responsive to the temperature in said heater for additionally controlling the exhaust of gas from said second chamber through said duct means.

2. A valve as claimed in claim 1, in which said magnetically actuated valve comprises a magnetic piston movable inside a hollow body and actuated by the variations in the magnetic field between one end of said magnetic piston and the magnetic member responsive to the variations in the water flow, said piston being provided with a resilient disc attached to the end thereof remote from said one end and positioned to cooperate with a seat in said duct means to control the exhaust of gas from said second chamber.

3. valve as claimed inclaim 2 in which the resilient disc attached to said magnetic piston controls; a connection between the second chamber of the diaphragm valve and a gas inlet to said burner, said connection being magnetically controlled in response to variations in the flow of water entering the water heater independently of variations in the temperature of the outlet water.

4. A valve as claimed in claim 1 in which said heat responsive valve means comprises a perforated pin in said duct means having in one end a gas outlet facing the conical end of a bellows responsive to the temperature of the water heated by said heater.

5. A valve as claimed in claim 4, in which said perforated pin is manually adjustable from outside the valve and said adjustment determines the amount of the maximum flow of exhaust gas and thereby determines the extent to which said diaphragm opens said outlet.

6. A valve as claimed inclaim 5, in which said perforated'pin is provided with at least one small diameter discharge orifice which permits a small exhaust flow sufficient to maintain a minimum flame at the burner even when the conical end of the bellows totally closes the outlet in the end of said perforated pin.

7. A valve as claimed in claim 1, which comprises an ignition retarding valve including a disc having at least one small orifice therein alignedwith a larger orifice in said duct means, said disc being enclosed in a housing having at least one orifice leading to said second chamber, said disc being positioned to be lifted by gas flowing into said second chamber to permit rapid charging thereof, but depressed to partially obstruct said larger orifice when gas is being exhausted from said second chamber.

8. A valve as claimed in claim 1 comprising electromagnetic closure means connected to cut off the flow of gas to said burner whenever a pilot light is unlit, and an activator pin capable of opening said closure means only when a main valve controlling gas flow to said burner is in its closed position.

Claims (8)

1. In a diaphragm valve for controlling the flow of gas to a water heater including a burner and equipped with a magnetic member responsive to variations in the flow of water to said heater, said valve comprising first and second chambers separated by a diaphragm, said first chamber being provided with a gas inlet and an outlet leading to said burner, and said diaphragm being movable between a first position closing said outlet and a second position in which said outlet is left open in dependence on the relative pressure in said chambers, the improvement which comprises duct means connecting said first and second chambers, and providing an exhaust for said second chamber, magnetically actuated valve means responsive to the position of said magnetic member and positioned to control the exhaust of gas from said second chamber through said duct means, and manually adjustable heat responsive valve means responsive to the temperature in said heater for additionally controlling the exhaust of gas from said second chamber through said duct means.

2. A valve as claimed in claim 1, in which said magnetically actuated valve comprises a magnetic piston movable inside a hollow body and actuated by the variations in the magnetic field between one end of said magnetic piston and the magnetic member responsive to the variations in the water flow, said piston being provided with a resilient disc attached to the end thereof remote from said one end and positioned to cooperate with a seat in said duct means to control the exhaust of gas from said second chamber.

3. A valve as claimed in claim 2, in which the resilient disc attached to said magnetic piston controls a connection between the second chamber of the diaphragm valve and a gas inlet to said burner, said connection being magnetically controlled in response to variations in the flow of water entering the water heater independently of variations in the temperature of the outlet water.

4. A valve as claimed in claim 1 in which said heat responsive valve means comprises a perforated pin in said duct means having in one end a gas outlet facing the conical end of a bellows responsive to the temperature of the water heated by said heater.

5. A valve as claimed in claim 4, in which said perforated pin is manually adjustable from outside the valve and said adjustment determines the amount of the maximum flow of exhaust gas and thereby determines the extent to which said diaphragm opens said outlet.

6. A valve as claimed in claim 5, in which said perforated pin is provided with at least one small diameter discharge orifice which permits a small exhaust flow sufficient to maintain a ''''minimum flame'''' at the burner even when the conical end of the bellows totally closes the outlet in the end of said perforated pin.

7. A valve as claimed in claim 1, which comprises an ignition retarding valve including a disc having at least one small orifice therein aligned with a larger orifice in said duct means, said disc being enclosed in a housing having at least one orifice leading to said second chamber, said disc being positioned to be lifted by gas flowing into said second chamber to permit rapid charging thereof, but depressed to partially obstruct said larger orifice when gas is being exhausted from said second chamber.

8. A valve as claimed in claim 1 comprising electromagnetic closure means connected to cut off the flow of gas to said burner whenever a pilot light is unlit, and an activator pin capable of opening said closure means only when a main valve controlling gas flow to said burner is in its closed position.

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