US2564869A

US2564869A - Control system for fluid fuel burners

Info

Publication number: US2564869A
Application number: US212549A
Authority: US
Inventors: Weber Victor
Original assignee: Robertshaw Fulton Controls Co
Current assignee: Robertshaw Controls Co
Priority date: 1951-02-24
Filing date: 1951-02-24
Publication date: 1951-08-21
Anticipated expiration: 1968-08-21

Description

Aug. 21, 1951 V. WEBER CONTROL.l SYSTEM FOR FLUID FUEL BURNERS Filed Feb. 24, 1951 INVENToR. Vwtop M/ebep.

HIS

,. mmm. WQ Nk Q %N @N um I m 1 N N n NNRE www 1% QN @N SMN Kw w 1 1 uva@ m www1@ im M mi NN SQ S |11 NNN J WN 1 4 @QN r AWN N @gm mk f TTRNE'Y Patented Aug. 2l, 1951 UNITED STATES PATENT CGNTWRQL` SYSTEM FORl FLUID FUELL- BURNERS Application February 24, 1951, SerialNo. 212,549.

invention relatos; to.- control. siisteino for.: fluioiuel-bizmersfonsilmoitepartioularly to. oleo.- trioally;onerehloapoeratlis o f thotypog.

In; fluid; fuol...burnine.i apparatus itis' often do.-` enable..v tof effect. automatic: operation. Cif; the; 5. ou big.y of: a. timing.. meoiiaei mi. To.; tbisend-. it .is @n.obieotof.: thiSzini/ontion-.to Goor-- infolinev atlmissionoi; fiieltof-tnefbiirners; timed". intervals,.-

' .Lfiirthenobisiot:offthis. invontionioroorir l0 assomme-of the-flou. motores valse. Anotiien objootof.- this invention is to control: admission f l. I

. this; invoniioir, is; to. oon:- Struotzthe ,oontiolsystem Withf.simpleinexpoosivoa parts;

Another object; of.- this: invention, to; permit: 20 theoperetion ofzitlieloiirners:inzthereyentof poil/oirv failli-re.

Apreferreiembodiment of; the present invoer tionoomp s a In burnonsuppliod"Withfuol bye conduit.:A the of.; fiiol which isunder. 25 theeoontrol of; a; n. to an open'. positie., b vf device responsive.- to., the presenoer; of nomefatr pilot biirrier- Fuolf fiowto; th normalilyoloseolf valve and.; to.. thevv pilot burnerfis con.. .rolled by a manually-operable 30 valve, thesupplyof' fue1.;to: which is intern: con: trolled". by a, normally.- open. oleotrio 1b.' operable valve. An electric igniter; is provldmed for the` loilotrburnerVr and has an en.oreizine` oiroiiitf oontrolled byfa timinefdevioe by asWi-toh mooie-- 3o anism operatively asso.ciatedL vvitlr` the manually; opl'afblvalym The timin devieyalsg'co 041s energizatfion of 151.1%.etc-tuating means- QI/ the npr;n rnally.l open. electrically: operable; valve.4

Furthen objects; and; advantages. will. be.. err 4.0 parent from the. aooomo. yme--soeo-.i-,oetion aiid claimsetaken with; the drayvingfvvliichlv' n matieviewoff a control; system for: a. iietb r; embodyingetnis inventiom. af..portion.tbereo;ii beine shown in the section is an improvement o. the; system.. disolosed.v and claimed in the oonomiine: application of Viotoe '165 fiIeLiNQVQmben 1.5,A 1.950-

21 ohio valve moans 1.6;: and oorineliv open... 61.8.0.-- trioaHy operable volvo here Shown a Solenoid. vali/,fi I8,

Ari; eieotrio, ienitoie 20. io diSROSesf. in'. gfities.- roietionwith @1 -.pilot buriiorzieiiirn dispose@ ienitirie relation with the burner: llt.

SP911SYe Va1Ve meffnse '4 Wrfl.; may" Q OIQPSJ- a; valve. ohorriloerv 1;8 formed: iii ton@ orpi/RiedA with. i111 i. outlet opening, 3.2.` T muiiioateoawitho nip burner |0- Disposed. 1.11; te Cham is a valve seat 36 cooperable with a.-L v x mont 38V to interrupt flowlo. =t.iif-.eon;y theinlet. 30 ondfthe outlet 32.1 A ooilzspr-.inefllt acts between a. Wall 42 ofthefvalve4 cl'iatnberi2K3 and thel valve member 38V to` bias. the valve member 333,- into` engagement with the; valve-seat 36 ,1

Depending. from` the lower side of; the. valve;` member 3 8 is a valve stemV 44 whichl extends. through a bore 46: in the4 casing 2.6. TheL di,-` ameter i of theA bore. 4,6\ is; sufficient;v to. permitaxial movement. of the valve. stem. 414 therein, The free. end 4.8 of;the..valvestem.A 44 extends beneath the. casing? 26:; to abut a leverk 50; which; is` pivotect at one.. endA 52K ina bracketA 54. secured toi. the casing. 26.

The lever El): is adapted to bev moved about its` pivot bya` thermally responsive device which may comprise the usual rexpansible element 56, capillarytube 58, and bulb 6U. The bulb (il)v is` disposed adjacent the pilot burnerv 22 to be-heatedv byna name emanating therefrom. Theexpansible element 56 is mounted` on a cover 62: secured` in fluid relatiorrlto the 10i/Verf side of they casing- 26 by any suitable means (not shown). Movement is transmitted from the expansible element 55 to the lever 5 6 by meansr ofV a thrust button` fifi; oarriedjonilie upper surface of: the. eilaiisbio. element. 56.. It will. be eppeiontihat. the ab.- Sonoo of.y a 11eme. at. theoilot boitier. 22..A the B2i: sensible.. element. 5.6, will. hein. oontraetodoor dition and. the Spring 4.0, will. hold.. the. Valve. member 3.8 ogeinst'tnovolyeseei. 3...@ It will` also. oo. apparent that e. flame emanating: irooiv the. pilot burner 22` will be.v effective to heat the bulb Sli to cause expansion of the expansibk element 565, counterclockwise rotation; 0 1A theleyen 50 v and o.; movement. of the. valve member 3.1i.. against iii-e bias of the spring 40 and away from the valve seat 36.

The manually operable means I6 may comprise a simple fuel cock (not shown) mounted in a casing 66 for rotation between fuel ow permitting and fuel flow preventing positions. Manual rotation of the cock may be effected by means of a knob 68 connected to the cock through a stem 10.

Fuel may be admitted to the casing 8G of the manually operable valve means I@ through a conduit 'I2 connected therewith and egress of fuel from the casing 56 may be had through a pair of outlets. One of the pair of outlets communicates with a conduit 'I4 which communicates with the inlet 30 of the valve chamber 28 of the thermally responsive valve means I4. The other of the pair of outlets communicates with the conduit 24 connected to the pilot burner 22. The manually operable valve means IS thus controls the flow of fuel to both the thermally responsive valve I4 and pilot burner 22.

Flow of fuel to the thermally responsive valve means I4 may also be under the control of condition responsive valve means which may comprise a thermostatically controlled valve combined with the manually operable valve means in a manner well known in the art. The thermostatic control for the thermostatically controlled valve may include a temperature sensing element here shown as a bulb 'I6 exposed to the temperature of the space to be heated by the main burner I and -connected to a valve actuating mechanism (not shown) by a capillary tube 18. Since combined fuel cocks and thermostatically controlled valves are well known in the art, further description is believed to be unnecessary.

The solenoid valve i8 is normally open and is adapted to be closed when the solenoid winding thereof is energized. The solenoid valve I8 is connected to a conduit 80 in communication with the supply conduit I2 and also to the conduit I2 which communicates with the casing 56 of the manually operable valve means I3. Thus, the solenoid valve I8 controls the flow of fuel to the manually operable valve means I3.

A stand-by pilot burner 82 is disposed in igniting relation with the main burner I0 and is connected to the supply conduit I2 by conduits 84 and 8B. Flow of fuel to the stand-by pilot burner 82 is under the control of valve means 88 which may comprise a valve chamber 90 formed in the casing 23 and provided with an inlet -92 and an outlet 94. ing 92 communicates with the conduit 8S and the outlet opening 94 communicates with the conduit B4. A valve seat 93 disposed in the valve chamber 90 is cooperable with a valve member 98 to interrupt flow between the inlet opening 92 and the outlet opening 94.

A valve stem |00 is slidably carried in a bore |02 formed in the casing 26 and extends between the valve member 98 and the level` 50 of the thermally responsive actuating means. It will be apparent that rotation of the lever 50 under the influence of a fiame at the pilot burner 22 will cause an upward movement of the valve stem |00 and associated valve member' 98 to move the valve member 93 away from the valve seat 96. When the valve member 98 is not so moved it will be held against the valve seat 3G by the pressure of the fuel supply acting thereon and by the bias of a spring 99 interposed between the valve member 198 and the casing 2 5 rThe inlet open- A standby pilot control of the type herein disclosed is disclosed and claimed in the copending application of Charles K. Strobel, Serial No. 189,584, filed October 11, 1950.

Also disposed Within the casing 23 is a thermally responsive switching device |34. Secured to the bottom of a recess formed in the casing 26 is an apertured element |98 formed of suitable insulating material and carrying thereon a pair of `contacts IIQ. The contacts |I0 are arranged in spaced relation and are engageable by a movable plate IIR to complete a circuit therebetween. A coil spring |I4 acts between the movable plate II2 and a closure` member IIB to bias the plate I I2 into engagement with the contacts II 0.

An operative connection is established between the movable plate II2 of the switching device |94 and the lever 50 of the thermally responsive actuating device by a push rod I I8 slidably carried in a bore |29 formed in the casing 26. The push rod I I8 extends through the apertured element |08 to engage the movable plate III) and also extends beneath the casing 29 to abut the lever 50. It will be apparent that when the expansible element 56 is in its nonexpanded condition, the coil spring IICI of the switching device |04 will maintain the plate II2 in en agement with the contacts H0 and that counterclockwise rotation of the lever 53 about its pivot 52, upon expansion of the expansible element 56, will cause upward movement of the push rod I|8 and the plate I|2 associated therewith to disengage the plate ||2 and the contacts IIS.

Movement of the solenoid valve between fuel ilow permitting and fuel flow preventing positions is under the control of a timing Ymechanism indicated generally by the reference numeral |22. This mechanism includes a double throw switch having a switch blade |24 pivoted at |25 to be alternatively movable into engagement with two fixed contacts I 28, |29. The switch blade |24 is connected to a reciprocal plunger |30 of a timer here shown as a clock |32. -The timer |32 may be of any suitable form and may be manually adjusted to cause axial movement of the plunger |30 at preselected times. It is understood that the timer |32 may also be manually adjusted to set and retain the plunger |30 in its retracted or extended position. As timing devices of this type are well known in the art, further description of the timer |32 is deemed unnecessary.

The switch I24-|28 of the clock actuated mechanism |22 forms a part of an energizing circuit for the solenoid of the solenoid valve I8 and serves to connect the solenoid winding of the solenoid valve to a source of commercial current here shown as line Wires LI and L2. Thus, movement of the solenoid valve between fuel flow permitting and fuel flow preventing positions is under the control of the timing mechanism |22. The energizing circuit for the solenoid winding of the solenoid valve I8 may be traced as follows: line wire LI, wire |33, wire |40, solenoid winding of solenoid valve I8, wire |42, contact |28, switch blade |24, contact |25, and wire |48, to line Wire L2.

Energization of the igniter 20 is under the control of the clock actuated switch I24-I29 and also under the control of a switch |32 operatively associated with the manually operable valve means I6. The switch |32 forms a part of the energizing circuit of the igniter 20 and is here shown as including an actuating lever |34 engageable by a camelement |36f carried byL the stem of the manually operable valve means |16 to be rotatable therewith. rllheswitch |32r is so designed that rotation ofthe knob- 58 to. close the f-uel cock of the manually operable valve means I6 will open the switch |32 and rotation of the knob 63 to openl the cock ofA theVV manually operable valveA means |6 will close` the switch |32.

lower terminal of` the primaryA winding offastep down transformer |152, primary winding ofthe transformer |52, upper terminal of: the primary winding ofthe transformer |252, wire |44', switch |:32,.wirev l.4.,x contact |129.. switch blade |24', contact |;26, and. wire |543.y toI line wire. L2.: Thus, when the.,l clock: actuated switch blade L24 is, in engagement with Contact |29.s.witch. |:3;2,is.closed and switching device |04 is. closed, current will flow through the primary winding. of. the trans.- former |52. Energization or the-primarvfwinding of; the transformer |52l will causea; current to be induced, in. the secondary winding thereof and suoni current will flow through a circuit.. which may he.v traced as follows: lower terminal; of. the secondary' winding of the transformer |52', Wire |54, ballast; resistor |563, wire |58J igniterv 20, Wire ls, ballast resistor |55 and wire |52 tothe upper terminal of the secondary winding of the trans.- former |52.

Operation Assuming that the apparatus is inthe condition shown in the drawing; with no flame existing at any ofi the, burners` and itv is desired; to. adjust thea-pparatus. for automatic operation, the timer |132. isv set to move.- the plunger |30; to.` movel the switch blade |24.out of engagement. with contact |28: and' into engagement, withv contact. |520. at. a selected time. and the knob G8. is rotated tomove the fuel cock of. the manually operable valve means IS to an open position. Such. rotation of the knob (i3 willr cause the cam element Izto engage the. actuating lever` |34 of; the switch |532 to close the. switch |32. so. that when the timer |32 moves. the switch. blade |24. into engagement with. the contact |29-, the. previously traced energizing circuit for the igniter 2|);iszccni-pletedV and: the igniter will become energized.,

When the switch blade |24 is moved. outzof engagement withY the contact; t2 85,. the previously traced. energizing., circuit forthesolenoid Winding is. broken and the. solenoid; valve. will.` assume its fuel ow permitting position.. Euelwillthenow from the supply conduit; I2 through` the' conduit 80. solenoid valve.; I8, conduit 12, manuallyl operable valve means. le, and conduit 24 to the.I pilot.

burner 22.y

Since the bulb 6010i; the thermally. responsive actuating means1 is in its unheated conditiom the mechanism in the casing 2.6, willbe inY the posi. tion shown, in` the drawing with the: thermally responsive valve means` |.4r preventing now of fuell toy the main burner, |03` thek standby pilot valve 88; preventing flow of fuel to the standby pilot burner 62, andthe plate |-|2 of; the switching device! 04 engaging theicontacts M0 to completethe previously tracedy energizing circuit of the ignter. 20. Current flowing through the igniter wi1l raise itstemperature sufficiently to,A cause ignition of. thefuel. flowing fromthe pilot bur-ner 2.2. to produce a flame directed against .the bulb 60.

Asy the temperature of] the bulb 6.0 increases, the expansible element 5&.wi11j expandcausing an upward movement of the thrust button 61|r andcounterclockwise rotation of the lever 50 about its Vpivot 52. As hereinbeforedescribed, such rota tion of? the lever 50'- will cause opening of' the normally closed valvefmeansf I4v and standby pilot valve 88# and'. movement.- of the plate ||2.- of the switching device 0.4'. out of' engagement: with the contacts: I0..

Thus fuel will ilowt from the. manually operable valvemeans. 6: through the conduit. 1.4, inlet opening 30 of valve means I4, valve chamber 20, past valve seat 3.6l through the.4 outlet opening 32 of the valve means 4, and through conduit 34 to the main burner |50. where: it will*A be ignited by the flame at. the pilot burner 22. Fuel will also flow from .the supplyY conduit I2y through the. conduit |36.y tothe valve; chamberl 9.0 of the standby pilot valve v 8 8; pastzthe valve seat 9,6; through the outlet opening 94j of the standby pilot valvev 88, and through the conduit 84' to the standby pilot burner |32A where it; will be: ignited bythe name. at the main burnerA l0.

When the plate. 22 ofthe switching device. |04. is movedj out; of engagement with the contacts 0, the energizing. circuitv for the igniter 20 is interrupted and the igniter 2.0 will be deenergized.v The igniter; 20;' will remain. in its deenera gized condition as long as a. flame exists atthe pilot burner 22.

rlhe apparatus isfnowr in its condition for steady state'operation with the ilow offuel to` the, main burner I0 through the conduit '|.4Ibeingunder the control of the thermostatically actuated valve as-i sociated. with; manually-operable.. valve means I6 in accordanceV with the. temperatures sensed by the temperaturefsensing element-'I6l If, whenthe. appara-tusfis infA condition for steady state operation, the llame at".y the pilot burners 20, 8.2. shouldv accidently be` extinguished, the bulb 60 willV cool. causing contraction of the expansible element 56 and clockwisey rotation of the lever 5:0 aboutits pivot-52 under the bias of the springs 40',v 9.9 and- ||4 to. position the plate. 2 ofV the switching device. |504. in engagement with the contacts |..|,0; and onceagaincomplete the energizing circuity for the. igniter- 20 to effect a recycling of the. system.

Whentheti-mer |3Zofjthe clock actuated mechanism |22 acts to move the switch bladey |24 out of engagement with` the contact. |25 and into engagementwith` the contact |23., the energizing circuiti of; theI solenoid' winding of the solenoid valve |8 is completed and.;the.solenoid winding is energized. The solenoid: valve.` |.0 will. then act to. shut off alli the flow of fiuel from thesupply conduit- |2 through. the conduit. 80. Thus the fuel supply tothemainburner I0 and tothe pilot burner 22 will.: be cut; off andf the flames a-t said burners will be ext-ingfuished.`

Upon extinguishment. or the-flame at the pilot burner 22,l the'bul-b. 60iwill cool causing contraction offthe expansiblei element 55A. and clockwise rotation of the lever, 5|).y about its pivot 52r under the` bias. of the springs 4.0. and H4. As hereinbefore set. forth,`sucl1 clockwise. rotation ofV the lever 50 will permit, the-valveV member iof the valve means M. to: engage its ..seat 35.. and thevalve member 9S. of thestandby. pilot, valve 8.8 willen.- gage its seat. 9.6.. Thus.. the fuelV supply to the standby pilot burner 82 will be out. off andI the flame thereat. will beV extinguished. The appaf ratus is now inthecondition shownin the drawi'ng with fuel supply to all burners prevented.

In the event of electric power failure, the solenoid Winding of the solenoid valve I8 will be deenergized regardless of the position of the switch blade |211 and the solenoid valve I8 will assume its normally open position. With the solenoid valve so positioned, the system may be operated manually merely by rotating the knob 68 to move the fuel cock of the manually operable valve means I6 to open position to admit fuel to the pilot burner 22 where it may be ignited by a match or the like. After ignition of the pilot flame, the various components of the system will automatically be positioned for steady state operation in the same manner as when power is available.

It will be apparent from the foregoing that the liereindisclosed apparatus provides a control systern for fluid fuel burners wherein a simple clock actuated switch is effective to control admission and ignition of fuel thereby providing for a simple economical clock control and that it accordingly accomplishes the objects of the invention.

Although a specific embodiment of the invention has -been shown and described, it will be apparent that many modifications may be made by those skilled in the art. Such modifications may be in the details of construction and arrangement of parts without departing from the scope of the invention as set forth in the appended claims.

It is claimed and desired to secure by I etters Patent:

1. In a fluid fuel burner control system, manually operable valve means for controlling the supply of fuel to the burner, normally open valve means for controlling the supply of fuel to said manually operable'valve means, electrically operable actuating means adapted when energized to close said normally open valve means, and timing means for controlling the energization of said actuating means at preselected intervals.

2. In a iiuid fuel burner control system, manually operable valve means for controlling the supply of fuel to the burner, normally open valve means for controlling the supply of fuel to said manually operable valve means, electrically operable actuating means adapted when energized to close said normally open valve means, an electric igniter for igniting fuel flowing from the burner, and timing means for selectively energizing said actuating means and said igniter at preselected intervals.

3. The control system as claimed in claim 2 wherein thermally responsive means are provided for deenergizing said electric igniter when a flame is established at the burner.

4. In a fluid fuel burner control system, manually operable valve means for controlling the supply of fuel to the burner, normally open valve means for controlling the supply of fuel to said manually operable valve means, electrically operable actuating means adapted when energized to close said normally open valve means, an energizing circuit for said actuating means, an electric igniter for igniting fuel flowing from the burner, an energizing circuit for said igniter, switching means for selectively closing said circuits, and timing means for actuating said switching means at preselected intervals.

5. A control system as claimed in claim 4 wherein said energizing circuit for said igniter includes a switch operatively associated with said manually operable valve means to be closed when said manually operable valve means is in fuel flow permitting position and open when said manually operable valve means is in fuel ow preventing position.

6. A control system as claimed in claim 5 wherein said energizing circuit for said igniter includes a thermally responsive switch for opening said igniter energizing circuit when a flame is established at the burner.

7. In a fluid fuel burner control system having main and pilot burners, means responsive to the presence of ame at the pilot burner for controlling the supply of fuel to the main burner, manually operable valve means for controlling the supply of fuel to said last named means and the pilot burner, an electric igniter for the pilot burner, normally open valve means for controlling the supply of fuel to said manually operable Valve means, electrically operable actuating means adapted when energized to close said normally open valve means, and timing means for selectively energizing said electric igniter and said actuating means at preselected intervals.

8. A control system as claimed in claim '7 wherein thermally responsive means are provided for deenergizing said electric igniter when a flame is established at the pilot burner.

9. In a uid fuel burner control system having main and pilot burners, an electric igniter for the pilot burner, means responsive to the presence of flame at the pilot burner for controlling the supply of fuel to the main burner, condition responsive valve means for controlling the now of fuel to said last named means, manually operable valve means for controlling the flow of fuel to said condition responsive valve means and to the pilot burner, normally open valve means for controlling the supply of fuel to said manually operable valve means, electrically operable actuating means adapted when energized to close said normally open valve means, an energizing circuit for said electric igniter, an energizing circuit for said electrically operable actuating means, switching means having a first position closing only said first named circuit and a second position closing only said last named circuit, and clock controlled means for moving said switching means between said positions.

l0. A control system as claimed in claim 9 wherein said energizing circuit for said igniter includes a switch operatively associated with said manually operable valve means to be moved between open and closed positions thereby when said manually operable valve means is moved between fuel ow permitting and fuel flow preventing positions.

l1. A control system as claimed in claim 10 wherein said energizing circuit for said igniter includes a thermally responsive switch for opening said igniter energizing circuit when a, flame is established at the pilot burner.

1'2. In a fluid fuel burner control system having main and pilot burners, an electric igniter for one of the pilot burners, means responsive to the presence of flame at said one pilot burner for controlling the supp-ly of fuel to the main burner, means responsive to the presence of flame at said one pilot burner for controlling the supply of fuel to another of the pilot burners, condition responsive valve means for controlling the flow of fuel to said rst named flame responsive means, manually operable valve means for controlling the flow of fuel to said condition responsive valve means and to said one pilot burner, normally open valve means for controlling the supply of fuel to said manually operable Valve means, electrically operable actuating means adapted when energized to close said normally open valve means, an energizing circuit for said electric igniter, an energizing circuit for said electrically operable actuating means, swtch'ing means having a first position closing only said rst named circuit and a second position closing only said last named circuit, and clock controlled means for moving said switching means between said positions.

13. A control system as claimed in claim 12 wherein said energizing circuit for said igniter includes a switch operatively associated with said manually operable valve means to be moved bel0 tween open and closed positions thereby when said manually operable valve means is moved between fuel flow permitting and fuel flow preventing positions.

14. A control system as claimed in claim 13 wherein said energizing circuit for said igniter includes a thermally responsive switch for opening said gniter energizing circuitl when a flame is established at said one pilot burner.

VICTOR WEBER.

No references cited.