US1636770A

US1636770A - Thermostatic filot control system for burners

Info

Publication number: US1636770A
Authority: US
Publication date: 1927-07-26
Anticipated expiration: 1944-07-26

Description

July 26, 1927. 0' FOX ET AL THERMOSTATIC PILOT CONTROL SYSTEM FOR BURNERS 26 1 I July v 0. FOX ET AL THERMOSTATIC PILOT CONTROL SYSTEM FOR BURNERS Filed April 14. 1926 zshqets-shet 2 I I I r 1 r I 1 i I I, 1 1

. son, be extin uished.

Patented July 26, 1927.

- UNITED. STATES PA ENT oFFIcE.

OTTO FOX, 01' CLEVELAND, AND WILLIE. I. STARK, OF EAST CLEVELAND, CHIC, AS- SIGNOBS 1'0 THE BRYANT HEATER AND MANUFACTURING COMPANY; OF CLEVE- LAND, 0310,; coarona'rxon or 0310.

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Application fled April 14', 1820. Serial No. 101,888.

This invention relates to a thermostatic pilot control for gas burners and has for its object to provide an improved and highly efficient system for preventing the flow of gas to the main and pilot burners in the event that the flame at any one or more of the pilot burners becomes extinguished.

In accordance with our invention and in its preferred embodiment, a main control- 1 ply of as into the portion of the chamber valve is employed preferably a diaphragm valve which is actuated automatica ly through the medium of a thermostat or other control device such as a steam regulator to control the flow of as to the main burner "or burners and in acfdition, we provide an auxiliary valve which is preferably also a diaphragm valve and which is actuated throu h the medium of a pilot thermostat and o --a valve associated therewith for controlling the main valve insuch a way as to prevent the latter bein opened if the flame at the pilot burner shou d, for any rea- The invention may be further briefly summarized asconsisting in certain novel details of construction and combinations and arrangements of parts which will be described in the specification and set forth in the appended claims.

In the accompanying sheets of drawings Fig. 1 is a more or less conventional representation of a system embodying my invention, parts being in elevation and parts beingin section;

Fig. 2 is an enlarged view part1 -.in elevation and partly in section of the pilot burner and control mechanism associated directly therewith; and

Fig. 3 is a sectional view through themain diaphragm valve showing the adaptation for a main control somewhat different than that illustrated in Fig. 1.

Referring now to the drawin' s,"10 represents the main gas supply pipe rom which gas is supplied through an automatically controlled valve 11, on the outlet side of which is a pipe112 connected to a. manifold 13 to which any number of maingas burners 14 may be connected, each separately controllable through the usual hand operated valve 15. [The main valve. 11 is pref erablv a diaphragm valve and comprises a chamber 11 and a diaphragm 11" wh'c'h is above tlediaphragm, the latter will drop onto the seat and prevent the flow of gas to the main burners until the" pressures are again unbalanced by reducing the pressure a ove the diaphragm.

I In thenormal operation of the system the flow of gas to the upper art of the chamber is controlled automatical y by a valve actuated in any of the usual ways as by a thermostat or steam pressure regulator. When a thermostat. is used it may be of the type which controls the t nperature of the water i in the storage tank r it may control it indirectly as when utilized in the control of room temperature in which event the valve ma be actuated by a motor in turn con; tro led by the thermostat.

In Fig. 1 we have shown a thermostat 16 of the first named t pe adapted to actuate a valve 17 which, w ien opened permits gas to flow to the upper part of the chamber 11 so as to seat tie diaphragm 11". In this instance a gas supply pipe 18 is connected to the lower part of the main control valve 11 and this is connected by a pipe 19 to the intake side of the chamber 17' of the thermostat controlled valve 17. The outlet side of this chamber has connected to it a pipe 20 in turn connected to a pipe 21 communicating with the upper part of the chamber 11 of the main control valve 11. It will be seen that when the thermostat 16 opens or permits valve 17 to open gas will flow from the lower side chamber of the main control valve 11 through pipes 18, 19,

through valve '17 and p1pes'20 and 21 to the upper side of the chamber of the main control valve thus uahzing the pressures on opposite sides of t e diap lragm and per- .mittmgitto drop by gravity onto the seat I is then reduced through the medium of an gas which is admitted tothe upper partof i escapement burner 22 having a small orifice 23 and connected by pipe 24 to pipe 21 leading to the upper part of the chamber of the main control valve. In consequence on the closing of the thermostat controlled valve 17, the pressure above the diaphragm is reduced and the diaphragm is liftedv permitting gas again to flow to the main burner or burners 14.

In Fig. 3 a main control valve 25 is shown having a chamber 25 and a diaphragm 25 which is operated similarly to that shown in Fig. 1 but. the flow of gas to the upper part of the chamber 25 is controlled in a somewhat different manner. In this instance, the

chamber 25 to seat the iaphragm, is supplied through a passageway 25 formed in the valve ohamber25, the lower end of this passageway connecting with the intake side of the'valve 25. The upper end ofv this passageway isadapted to be placed in communication with the upper part of the valve chambcr 25- by a small valve 26 arranged in the upper part'of the chamber. The opening opened by the lowering of the weighted lever and is closed by a small springwhen the weighted lever is. elevated but the valve 26 can be constructed and operated otherwise if desired.

.In Fig. 3 the upper part of the valve chamber 25 has connected to it the pipe 21 lead-' ing to the escapement burner 22, asshown in Fig. 1, and the lower part of the chamber 25 has connected to it a gas supply pipe 18 as in the construction first described.

Coming now to the parts or features more directly involving my invention, the pilot burner which is associated with the main burner in Fig. 1 is shown at 28. As there may be any number of main burners 14 so there may also be any number of pilot burners 28, one associated with each main burner if desired. By reference particularly to Fig. 2 it will be seen that the pilot burner is provided at the top with a series of orifices 29 and is provided at the bottom with a restricted orifice 30. Gas is normally supplied to the pilot burner by a pipe 31 connected to a chamber 32. This in turn is connected by a pipe 33 to a'pilot burner manifold 34 to which the different pilots are connected if more than one pilot is employed. By referring again to Fig. 2 it will be noted that associated with each pilot 28 is a thermostat .35 which in this instance is attached directly to the pilot a short. distance below the burner openings 29.. The lower end of the thermostat abuts againstn rod 36 which extends freely through a pipe 37 connected to the chamber 32. The rod 36 also extends into the chamber 32 and at its inner end is provided with a valve 38 adapted to engage a seat 39 which is formed in chamber 32 and toward which the valve is urged by spring 40. The arrangement is such that the thermostat 35 when heated 'will allowthe valve 38 to be seated so as to close off communication between chamber 32 and pipe 37, but when the thQI'IIIOSltli. is cooled it unscats the valve against the pres.- sure of spring 40 and allows gas to flow from the chamber 32 through pipe 37 as well as through the pipe 31 leading to thepilot burner.

At the outer end of the pipe 37 there is a gas outlet pipe '41 having' a,seaies of orifices 42, the area of which is greater than that of the orifice 30 leading to the pilot burner and in fact greater than the aggregate area of the orifices 30 of all the pilot burners assuming that there may be more than one. The function of the thermostat and of the arrangement illustrated inFigs. 1 and 2 in conplained presently.

Gas is adapted to be supplied to the pilot manifold 34 and thereby to the different pilot burners from the pipe 18 which, as previously explained, is connected to the. lower side of the chamber of the main control valve 11 shown in Fig.1 or main con.- trol valve 25 of Fig. 3. The pipe 18 leading to the lower side of the chamber of the main of connection for the supply pipe for the pi'lot'burners but a connection with any other point 011 the intakeside of the main control valve or on the intake side of the diaphragm 11 thereof will do as well.

It is an important feature of my invention nection with the pilot burner will be excontrol valve is simply a convenient point that thereis arranged between the-pilot manifold 34 and the pipe 18 a special automatic valve 43 which is preferably a. diaphragm valve composed of a casing or chamber 43 and a diaphragm 43 having an upper seat 43 and a lower seat 43 7 Two pipe connections are made with chamber 43" on each side of the diaphragm 43 The connections on the upper side consist of a pipe 44 connected to a. pipe 45 in turn connected to supply pipe 18 communicating with the lower side of the chamber of the main control valve, as already explained, the other connection to the upper side of the chamber being a pipe 46 leading to the pilot manifold 34. It may be here stated that normally the diaphragm is down or in engagement with the lower seat 43, in whichevent' gas passes' normally closed.

nose-17c continually from pipe 18 and pipes 45, 44'

the upper part of the chamber 43' and pipe 46 to t e pilot manifold 34.

The two ipe connections with the lower to a pipe 49 which in turn is connected to pipe 21 leading to the up r side of the chamber of the main contro valve.

The apparatus is completed b two small by-pass plpes one consisting o by-pass 50 between the gas supply pipe leading to the upper part of the chamber 43 and the g therefrom. This provi ed with a cock 51 small push-button which is preferab y cock. The other by-pass ipe 52 is between pipe 49 and pipe 46, this y-pass pipe being provided with an ordinary cook 53. There is preferably provided also a cock 11,54. in gas supply pipe 45 between pi 44 shown in Fig. 1. The 000 51 and 53 are The system operates as follows:

During normal operation gas flows continuously from the lower part of the maincontrol valve'and through'the upper partof the auxiliary diaphragm valve to the pilot burner or burners 28. During this normal operation the auxiliary valve controlled by thermostat 35 is closed since the thermostat is heated by the flame at the pilot burner.

Y In consequence no gas passes through the pipe or tube 37. During such normal operation the flow of gas to the main burner or burners is controlled in the customary way by the thermostat or steam regulator, the

latter controlling the valve which permits or stops flow of gas above the diaphra m of the main control valve so as to perm1t the diaphragm to be seated or unseated'. If While the gas is shut oil from the main burner or burners, the flame .at the pilot burner 28 or any one of the series of pilot burners should be extinguished the thermostat 35 associated withthe particular pilot burner in question cools ofi and as it cools it unseats or opens valve.38 permitting a free flow of gas through pipe 37 and orifices 42. As before stated, these ports are so proportioned that they are much larger than the combined area of the orifices of all the pilot burners connected to manifold 34. The opening of valve 38, therefore,results in an increased amount of gas immediately pass ing through the'entire pilot line and produces a decided drop in pressure in the upper part of the chamber of the auxiliary-diaphragm valve 43. Since the pressure above diaphragm 43 is reduced it becomes overbalanced by the pressure below the diaphragm and causes the diaphra to raise and to be seated on the upper va ve seat 43. lhe raising of the diaphragm shuts off nd 47, as

the flow of gas to all pilot burners and additionally it permits gas to'flow through pipe 47 and throu h the lower part of the chamber of the vsfive 43 and

h pi cs

48, 49 and 21 to\ the upper part of t e c iamber of the main control valve.

Now if the supply of gas through pipes 19 and-20 to pipe 21 is cut oil by the action of the steam regulator or thermostat the diaphragm of the main valve is unable to rise as the pressure above it is maintained by the flow of gas through the auxiliary diaphragm valve and

pipes

48 and 49. Thus the flow of gas to the main burners and to the pilot burners is shut ofl and during this time the flow of gas through escapement burner is restricted to the very small amount that will pass through the orifice 23, this being practically a negligible amount.

Let it be assumed that the house owner desires to relight the burners 14. Push button 51 which is provided to permitrelighting with safety is depressed and gas flows throu h the small line to pilot manifold 34 and to the pilot burner or burners. The gas may now be lighted at the ports 42.

Durin this time the diaphragm 43 of the aux' iary diaphragm valve will remain seated against the upper valve seat 43 since the ports 14 are so large in comparison with that sufficient gas pressure would be unable to build up, in the upper part of the chamber of'the auxiliary diaphragm valve to cause the diaphragm to dro onto the seat 43.

However, as soon as t e thermostat 35 be the passage through push-button valve 51 pipe 50 and pipe 46 to cause the diaphragm 43 to be lowered on the seat 43 this being true because the flow of gas is restricted by the orifice or orifices 30 of the pilot burner bodies.

The flow of gas through

pipes

49, 48 and 21 to the upper part of the chamber of the main valve 11 is now-stopped permitting the gas pressure in the upper chainber of valve 15 to be relieved through escapement burner 22. Diaphragm 11 is now raised by gas pressure beneath permitting gas to flow to burner or burners 14.

Push button valve 51 is normally held shut by a spring, and as soon as the diaphragm 43 of the auxiliary diaphragm valve has dropped onto seat 43 the push button may be released and the pilot or pilots will be fed in the normal manner through pipes 45,

generally operated by one hand and the no pilot or pilots are lit with the other, it is person to operate the push button valve and light all the pilot burners. Accordingly bypass 52 and cook 53 with .its' small orifice are provided to facilitate the lighting of such boilers. t

In the latter case the operator'will open cock 53 instead of the push button cock 51 thus permitting a small amount of gas to flow through cock 53 to pilot manifold 34 and pilots including the orifices 42, this gas ofcoursc being fed through pipe 45 leading from the lower part of the chamber of the auxiliary diaphragm valve 4;). The pilots may now be lighted and push button cock 51 may be opened to increase the flow of gas and hence the heat of the pilots. As soon as the pilots are heated and the valves 38 close thus restricting the flow of gas through the pilots, pressure accumulates in the upper part of the chamber of auxiliary diaphragm valve 43' causing the diaphragm 43" to be seated on the lower seat 43 thus stoppin the flow of gas through the lower part of the chamber of auxiliary diaphragm valve but there is a sufiicient flow of gas through by-pass pipe 52 into pipe 49 to prevent the lifting of the diaphragm of the main shut-off valve until cock 53 is closed and when this cock is closed the system will operate normally. I

The lower end of pipe 44 which normally supplies gas to the upper part of the chamber of the auxiliary control valve 43 is prefprovided with an orifice 44, this erably orifice ein'g comparatively large. When the pilot is burning in the normal manner the flow of gas is so small that this orifice" has no throttling effect but when the flame is extinguished the increased flow of gasthrough the orifice causes it to reduce the pressure on top of the diaphragm 43 much more rapidly than would be the case if the full area of piping 44 were available for the flow of gas. The apparatus will function without this orifice but not as quickly as desiied, the principal effect of the orifice being therefore to accelerate the action of the pilot. I I

Having thus described our invention what we claim is: a 1. In a thermostatic pilot control system for burners, a main burner, a pipe for supplying gas thereto, a pilot burner having a thermostat, a' .valve associated with the thermostat and adapted to be opened when the thermostat cools by the extinguishment of the flame of the pilot burner, a main control valve, and means whereby the. opening of the first mentioned valve prevents opening of the main control valve.

' 2. In a thermostatic pilot control system for burners, a main burner, a pilot bdrner,

oam-77o a main control valve, a-thermostat associated" with the pilot burner,.a valve adapted to be operated.- thereby and a third valve controlled by the second mentioned valve and servin to prevent the opening of the main contro valve when the flame is extinguished.

at the pilot burner.

In a thermostatic pilot controlsystem for gas burners, a main burner, a pilot bumer. an 11111201118110 main control valve of the pressure actuated type, a thermostat associated with the pilot burner, a valve controlled thereby, a third valve which is controlled by thesecond mentioned valve and serving to cause pressure to be applied to the main valve so as to preventthe opening thereof when the flame is extinguished at the pilot burner.

4. ln a thermostaticpilot control system for burners, a main burner, a pilotburner, a gas supply pipe, ajmain'control valve for controlling the supply of gas to the main burner, means comprisingadiaphragm valve for controlling the supply of-gas to the pilot burner and for preventing the opening of the main control valveiand means operated by the thermostat forcontrolling said diaphragm valve. a

5. In a thermostatic pilot control system for burners, a main burner, a pilot burner having a thermostat. associated therewith, a

main control valve of the diaphragm type for controlling the flow of gas to the mamv burner, means comprising an auxiliary control valve of the diaphragm type for controlling the flow of gas to the pilot burner and for controlling the flow 'of gas to the main control valve to prevent the opening thereof and means operated by the thermostat for controlling said auxiliary control valve.

6. In a thermostatic pilot control system for burners,-a main burner, a pilot burner having a .thermostat, a main control valve of the diaphragm type for controlling the flow of gas to the main burner, means comprising an auxiliary control valve of the diaphragm type for controlling the flow of gas to the pilot burner and the fiow of gas to one side of the diaphragm of the main control valve, and means comprising a valve operated by the thermostat for controlling the auxiliary control valve.

7. In a thermostatic pilot control system for burners, a main burner, a pilot burner having a thermostat associated therewith, a; gas supply pipe, a main control valve of the diaphragm type for controlling the flow of and ada ted to-be opened through the movement 0 the thermostat when the flame at the pilot burner is extinguished for controlling the auxiliary control valve.

8. In a thermostatic pilot control system for burners, a main burner, a pilot burner having a thermostat, a gas supply pipe, at main'control valve of the diaphragm type for controlling the flow of gas to the main burner, means comprising an auxiliary control valve of the diaphragm =ty. for controlling the flow of gas to the pilot burner, a normally closed valve associated with the thermostat and adapted to be opened throu h the movement of the thermostat when he flame at the pilot burner is extinguished, and means by which a drop in gas pressure produced by the opening of the thermostatically controlled valve operates to control the auxiliary control valve.

9. In a thermostatic pilot control system for burners, a main burner, a pilot burner having a thermostat associated therewith, a

gas supply pipe, a-main control valve of the diaphragm type for controlling the flow of gas to the mam burner, and means comprising a. normally closed valve associated with the thermostat and adapted to be opened through the movement of the thermostat when the flame of the pilot burner is extinguished for controlling the main control valve.

10. In a thermostatic pilot control system burner, means comprisin a normally closed l valve associated with t e "thermostat and K,

adapted to be opened throu h the movement of the thermostat when t e flame at the pilot burner is extinguished, and means whereby the reduetion in gas pressurecaused by the opening of said normally closed valve effects the closing of the main control valve. 11. A pilot control valve of the type described comprising a pilot burner, and a thermostat associated with the pilot burner, adapted to open a normally closed valve upon the extingnishment of the pilot flame to reduce the pressure in a gas supply line.

12. A pilot contrbl valve of the type described comprising a member ada ted to be secured to a gas supply pipe, 9. pi ot burner carried by said member, a thermostat associated with said pilot burner, and 8. normally closed valve mounted in said member, the extinguishment of the flame of the pilot burner causing the opening of said valve tov thereby reduce the pressure within the gas supply p1 In test niiony whereof, we hereunto afiix our signatures. i

OTTO FOX. WILLET E. STARK.