US2659844A

US2659844A - Burner control system

Info

Publication number: US2659844A
Application number: US782415A
Authority: US
Inventors: Russell B Matthews
Original assignee: Milwaukee Gas Specialty Co
Current assignee: Milwaukee Gas Specialty Co
Priority date: 1947-10-27
Filing date: 1947-10-27
Publication date: 1953-11-17
Anticipated expiration: 1970-11-17

Description

NOV. 17, 1953 B MATTHEWS 2,659,844

BURNER CONTROL SYSTEM Filed 001;. 27. 1947 3 Sheets-Sheet l l INVENTOR. JQwsell ,flflfiews fl wo. iullllu b01244 J NOV. 17; 1 953 MATTHEWS 2,659,844

' BURNER CONTROL SYSTEM Filed 001;. 27. 1947 3 Sheets-Sheet 2 I INVENTOR. fiwsellfiiflawezw BY Nov. 17, 1953 MATTHEWS 2,659,844

BURNER CONTROL SYSTEM Filed Oct. 27, 1947 .3 Sheets-Sheet 31 INVENTOR. PwSeZZB fiiafihezas Patented Nov. 17, 1953 UNIT-ETD? PATENT OFFICE BURN ER CONTROL SYSTEM Russell B. ,Matthews,:Wauwatosa,- Wis., assignontoQMilWaukeGfiIs- Specialty Company, Mil-.. wankee, Wi's.',-a corporation of Wisconsin Application ctober127, 1947; Serial No. 782,415

This :invention arelates; in.;genera1,@:.. to. .burner control. systems, sand is; particularly ;concerned- 1 with robtaining .quick -fuel--:.shutoifof "such sy r; temsiwhen the pilot flame is-..ex.tinguished;1.. n

While qui'ckfueli'shutoff :systemszof the char--- H acter. disclosed and.;claimed in the *present ape plication are particularly-useful inindustrialzig.--, nition :systems, it uislto'zbe nnderstoodthat the. invention-is: not limited to such 'use-butmay be employed .indomestic ":burner control. systems and elsewhere as suitable or-desired;

In the case ofagaseburnenqor a :seriesrofgas burners, .the. gas; is usually :mixed: with air in a A. mixing? jchambers adjacent to each :burnenr-and. the:scombustiblemixtureof gas and "ainisconducted to the. burner. orzburnersrwhere. it isxigv nited: by: a pilot flame. -.in.';lighting'iproximity j-to each 1 burner: If. there. is. delay; in the .fuel .shute off. when the :pilotfla-me is extinguished, a highly; explosivex gas-Fair: mixture may escape: unlighted-flo from .the burner, thusmresenting athe. apossibil-.-.. ity; of; .a :serious and:disastrous.T-explosion;; {par-4 ticularly where it is. attempted--promptly to rea light the pilot burner.

One. of..the. main. objectsziof'; the:=1p1:esent.;inventionzisto. provide'improyed' meansilwhich .,will operate automatically. to. provideiquickf-iuel zshuts': ofi Iofzthe. system .when :the -pilot name is extin'e guishedz i' Anothert'robjecti ofrther invention is tomrovide" variable :means. for adjusting the time for fuel shutoff latter thepilot name is extinguished;

Another object of the invention is to provide: variable means for 'adjustingjth'e time fo'r'iuel tu'rnmn-xafterthe] pilot flame: has beem'ignited", :5 35.

and, more particularly; an impr oved.:fcombina-i tion'of" variable%-.means for adjustingebotlrlthe time for"fuel'shutofi after the pilot flame is'.ex-. tinguished and the time...for fuel'turn-on'aftr the pilot flame has been :ignitedf Another object 'of the inventionis to elimir. nate or reduce. relay chatter bytusing .D. C! cur rent toenergizeitherelays;

Anothen'object. or the invention is to provide a system in 1' which "greater. .stability' is assured tion will appear from; the following. .detailed. .de-.

scription, taken in. connection with .the' accom-v panyingdrawingsiwhich illustrate the manner-1 of :constructing and operating vcertain embodi+- ments of" the invention.

In the drawings:-

Figure 1 is a diagram showing, schematically; the parts and circuit connections of one formiiofs.

system embodying the-present invention;

Figure? is a diagram showing another: form of: systemernbcdying the invention; and I Figure 3 is a diagram showing a further forms.

of system embodying the inventions:

Referring first to Figure"'1,.the burner shown a The use of the invention with'a series of burners is a1so.'contemplated.:= The burner l,' which,':of course," is illustrative;- maybe the mainburner-fora :lOOlIlxDlfiSDQCBI heater; or it maybe the burnerfor a water heats eror-for a floor furnace, anoven burner,:oneor.. more top burnersfora -gas-.range,-.or anyzother burner or series of. burners, .and' of any: suitable at I is a main burner.

construction.

electricallyv operated type.

by a rin 7 Electric. power is applied froma suitable-source of";current,.. suchas, for example, the .-.usua1.. -120 volt alternating .,current. 1ine....which is' shown as comprising conductors 8 and 9. .Conductor- 8 is adapted to be connected by. a .push button switch H) with conductor ll whichexe. tends 'to and-is-conne'cted in circuit with contact. |2-of-a relay 13. The other contactM of relay.

[3 is connectedin circuit-with one end "of coil I5 of relay [6 bycondu'cto'r I'B'i Conductor!) extendsttoand is connected in circuit with the op posite end. of coil [5.

Relay :16 has; a pair of normally closed contacts. and..l8 and. a second pair of' normally' open contacts I9 and 20. (relay. l6 deenergizedif Contact. This :connectedby a conductor H in circuit: with one .sidezofcoil'i of valve l, and the other sideof coil 6 isiconnected. by. a conductor,

22: in circuit with. the conductor 9. An alarm :or

othersuitable signal =device-23; audibleor visible, is connected. across conductors %2l-and; .22.- The other contact. l8 which cooperates with con- 3 tact I1, is connected by a conductor 24 in circuit with conductor H.

Interposed in fuel supply pipe 2 anterior of valve 4 is a manual shutoff valve 25. A pilot burner 25, located in juxtaposition or in lighting proximity to burner I, is supplied with fuel by a pilot supply pipe or conduit 21 connected to the fuel supply conduit 2, for example, at 28, between valves 25 and 4, or otherwise supplied with fuel.

A thermoelectric generator 29such as a thermocouple or thermopileis located in juxtaposition to the pilot burner 26 so that its hot thermojunction, or thermojunctions, will be heated by the pilot flame 30 as long as the pilot burner is ignited. One side of the thermoelectric gene rator 29 is connected by a conductor 3| in circuit with relay contact I9. The other contact 20, which cooperates with contact I9, is connected by a conductor 32 in circuit with one end of coil 33 of relay I3. The other end of relay coil 33 is connected by a conductor 34 in circuit with the other side of thermoelectric generator 29. An adjustable resistor 35 is connected to the conductor 32 at 36, and the adjustable contact 31 of the resistor 35 is connected to conductor 3I at 33.

In operation, opening valve 25 admits gas to solenoid valve 4 and pilot burner 26. Line voltage applied to conductors 8 and 9 (push button switch I being closed) energizes relay coil I5 through conductor 8, push button switch It), conductor II, contacts I2, I4, conductor I6, relay coil I5 and conductor 9. Contacts I2, I4 are closed when relay coil 33 is deenergized, which occurs when pilot flame 30 is not burning and thermoelectric generator 29 is cold. When relay I6 is energized, contacts II, I8 are opened, and contacts I9, are closed, which shorts out the fuel shutoff time adjustment resistor 35.

When pilot burner is ignited, the hot thermojunction or thermojunctions of thermo electric generator 29 become hot and relay coil 33 is energized through a path consisting of conductor 3|, contacts I9, 20, conductor 32, relay coil 33, and conductor 34, and relay coil I5 is deenergized. Deenergizing relay coil I5 closes contacts II, I8 and opens contacts I9, 20. When contacts II, I8 are closed, power is applied to solenoid valve 4 and alarm 23 through conductors 9 and 22, coil 6 of solenoid valve 4, conductor 2 I, contacts I'I, I8, conductors 24 and II, push button switch I0 and conductor 3. Energizing solenoid valve 4 opens this valve, and fuel is supplied to the main burner I When contacts I9, 20 are opened, resistor 35 is placed in the circuit of the thermoelectric generator. With adjustable resistor 35 in the circuit it is possible to regulate the drop-out time of relay I3 as desired. With resistor 35 shorted out of the circuit, relay I3 assumes its normal pull-in time which depends on current strength.

If the flame of the pilot burner 26 is extinguished, the hot thermojunction or thermojunctions of the thermoelectric generator 29 cool, and relay I3 deenergizes quickly because of the presence of the resistor 35 in the circuit of the thermoelectric generator at such time. When the relay I3 deenergizes, contacts I2, I4 close and relay I3 is again energized as previously stated. When relay I6 is energized, contacts I'I, I8 are opened and contacts I9, 20 are closed, which shorts out the fuel shut-oil time adjust ment resistor 35.

When contacts II, I8 are opened, power is re- Contacts I2, I4 open,

moved from the solenoid valve 4 and from the alarm 23. Upon deenergization of solenoid valve 4 the valve operates to closed position and shuts off the gas supply to the main burner. The circuit is now ready for a new cycle of operation.

In the system shown in Figure 2, the main burner, mixing chamber, fuel supply pipe or conduit for supplying fuel to the main burner, manual shutofi? valve, pilot burner and its connection with the fuel supply conduit and thermoelectric generator are similar to the showing in Figure l and are designated by primed reference characters corresponding with the reference characters used in Figure 1.

In Figure 2 electric power is supplied from a suitable source of current, such as, for example, the usual 110-12O volt alternating current line which is shown as comprising conductors 40 and M.

Line voltage applied to conductors 40 and H supplies potential to a voltage and current regulated rectifier circuit through conductor 40, push button switch 42, conductors 43 and 44, dropping resistor 45, and conductor 46, rectifier 41, and conductors 48 and II. Compensating resistor regulates the current through the circuit; voltage regulating tube 49, which shunts rectifier 41 by conductors 50 and 5I, regulates the voltage. When power is applied to the rectifier circuit, its D. C. output energizes coil 52 of relay 53 through a path comprising conductors 54 and 55, relay coil 52, thermoelectric generator 29', conductors 5B and 51, and fuel shutoff time adjustment resistor 58, fuel turn-on time adjustment resistor 59, and conductor 60.

With relay 53 energized, contacts 6| are open and coil 62 of relay 63 cannot be energized. With relay coil 62 deenergized, contacts 64 are open and contacts 65 are open, which places fuel turn-on adjustment resistor 59 in the circuit of the thermoelectric generator 29'. Capacitor 62, shown, for example, in the form of a fixed capacitor, shunts relay coil 52.

The polarity of the thermoelectric generator 29' is so arranged that when pilot burner 26' is ignited and the hot thermojunction or thermojunctions of the thermoelectric generator 29' are hot or heated, the voltage of the thermoelectric generator 29' supplied through conductors 56 and opposes the voltage produced in resistor I3 by the rectifier. The voltage produced across resistor I3 by the rectifier can be adjusted by fuel turn-on time adjustment variable resistor 59. When the voltage applied by the thermoelectric generator becomes great enough, relay coil 52 is deenergized and relay contacts 6| close. When contacts BI close, relay coil 62 is energized through conductor 40, push button switch 42, conductor 43, relay coil 52. conductor 65, contacts BI, and conductors 81 and 4I.

When relay coil 62 is energized, contacts 54 and close. When contacts 64 close, power is supplied to coil 6' of solenoid valve 4, and alarm or signal 23 through conductor 40, push button switch 42,

conductors

43 and 68, contacts 64, conductor 69, coil 6' of solenoid valve 4', alarm 23, and conductors I0 and 4|. Energizing coil 6' of solenoid valve 4 opens the solenoid valve and fuel is supplied to main burner I. When contacts 65 close, resistor 59 is shorted out of circuit through conductor 'II, contacts 65 and conductor I2.

When resistor 59 is shorted out of circuit, the current through relay coil 52 from the rectifier ofscurrentgfrom thermoelectric generator 2 9 is necessary to .open relay; contacts 5 I .1 This-pro vides for quick fuel turn-on time.

When, ythe pilo,t1- flame of; pilot; burne fiflfi is extinguished, thezf hotfthermojunction or.;ther;;- mojunctions. of. thermoelectric genera-ton '.-,co9. 1;

relay coil. 52;; is energized, contacts 16 l open, an

relay coil v62 i-sdeenergized; When relay coil 162; is ideenergized, contacts i64;:and 65; open=-; When contacts 64 open, power; is ;re,moved from coil 6"; of;solenoid, valve andsalarmcr signal 235 is .rdeenergized. Solenoid; valve :4 closes swhenq deenergized, and shuts :off the:supply of gas-to;

the main burner l. The openingof contacts 65 placesyresistor 59 intheccircuity- The-.circuit 315';

now readyfor a new cycle/of operation;v

Like the system shown in Figure '1, the system supplyto a burner-m series of burners when the pilot flame is extinguished; also a variable means of adjusting the time-for ;fuel shut-offhafter. the pilot is extinguished, The system sh own in Figure 2 also provides a variable means of adjusting the time for fuel turn-on after the pilot has been lighted. The relay and sliding contactsqof Figure) are operable at. a highervoltage potens tial than possiblewith the systemshown in :Fig-, ure- 1,. although,. of course, the systems =may. be, varied in these. respects.

Inmthe system .shown .inFigure 3, themain: burner, mixing chamber, fuelsupply pipeorcon duit. ifor supplyingnfuel -toythe main fburner, manual shut-off ,valve, pilot burner; and, its cone; e io t he fuel .su p yc ndu t d t rmos electric generator are similar; to-' those shown in; Fi e. :a d re desi na dzb r t imed: reference characters corresponding with the reference characters used in Figure 1.

In Figure 3, electric power is supplied from a suitable source of current, such as, for example, the usual 110-120 volt alternating current line which is shown as comprising conductors and 16.

In operation of the system shown in Figure 3, opening of valve admits gas to solenoid valve 4" and pilot burner 26". to conductors l5 and 16 supplies power to rectifier 11 through conductor 15, push button switch 18, conductor 19, rectifier I1, dropping resistor 80, conductor 8|, contacts 82 of relay 83, and conductor 16. Contacts 82 are closed when coil 84 of relay 83 is deenergized, which occurs when pilot burner 26" is extinguished and the hot thermojunction or thermojunctions of thermoelectric generator 29" are cold. When rectifier I1 is supplied with potential, coil 84' of relay 85 becomes energized through conductor 86, relay coil 84', and

conductors

81 and 88. When relay coil 84 is energized, contacts 89 are opened, and contacts 90 are closed, which shorts the fuel shut-ofi time drop-out resistor 9| out of circuit.

When pilot burner 26" is ignited, the hot thermojunction or thermojunctions of thermoelectric generator 29" become hot or are heated and relay coil 84 is energized through a path comprising conductor 92, relay coil 84, conductor 93, contacts 90 and conductors 94 and 95. When relay 83 is energized, contacts 82 open and relay coil 84 is deenergized. Deenergizing relay coil 84' closes contacts 89 and opens contacts 90. When contacts 89 are closed power is applied Line voltage applied 2 shown-in Figure 2 provides-jmeanszaifor;;auto-r matically turning on and shutting off the fuels s oenai -:5": o esolen i .v l e- '2;and alar, through conductor 15, push button switch 1 burner 21 placed .in- ;the circuit. ,,The movable contact of radjustable resistor 9| is connected:totconductor 94at l00.; Capacitor Hll, shown in the form of a fixed capacitor, and a variable resistor. 1102 shunt relay ,coil. 84'.

With adjustable resistor. 9| in: the .circuit, 'it-..- qis possible to regulate the drop-out time of relay;

83 Withresistor 9|:shorted out of circuit, relay 83" assumes its normal pull-in time. If the flame of pilotburner 26 is extinguished, the *hot: thermojunction or thermojuncti-onsof thermo electric generator 29". cool, and relay 83 isde Whenrelay 83 is deenergized, contacts '82 close and relay coil 84 is again energized, as stated previously When relay coil 84 is energized, contacts I ----'89 are opened and contacts-90 are-closed, whichenergized quickly because of resistor 9|,

shortsout quick dropout resistor 9|"; When the solenoid valve 4.

ready for a new cycle ofoperati on.

Like the systems shown in Figures 1 and 2, the system shown in Figure 3 provides means for.

automatically turning on and shutting off "the fuel supply to a burner or series of burners, and

for simultaneously operating an alarm or signal system'when the pilot flame is extinguished; also 5 a variable means-of adjusting the: time-for-fuel shut-off after the pilot flame -is extinguished.

With the system shown in Figure 3, relay chatter is eliminated by using D. C. current to energize the relays, and a greater stability is assured on short fuel shutoff time.

The embodiments of the invention shown in the drawings are for illustrative purposes only, and it is to be expressly understood that said drawings and the accompanying specification are not to be construed as a definition of the limits or scope of the invention, reference being had to the appended claims for that purpose.

I claim:

1. Thermoelectric control means comprising, in combination, an electroresponsive control device having operating and safety positions, a first circuit for energization by a source of electric power, a thermoelectric generator adapted when heated to establish a thermoelectric current, first means under control of thermoelectric current established by said thermoelectric generator and operating conjointly with second means under control of said first circuit for causing application of electric power from said first circuit to said electroresponsive control device to operate same to its operating position when said thermoelectric generator is heated, resistor means, and third means under control of said first circuit for completing a circuit including said thermoelectric generator, said resistor means, and said first means upon application of electric power from said first circuit to said electroresponsive control device, said resistor means acting to increase the rapidity of action of said electroresponsive control device to a safety position upon cessation of heating of said thermoelectric generator.

2. Thermoelectric control means according to claim 1 wherein the resistor means is adjustable to adjust the interval of time between cessation of heating of the thermoelectric generator and op eration of the electroresponsive control device to safety position.

3. Thermoelectric control means according to claim 1 wherein the resistor means is adjustable and by its adjustment acts to adjust the interval of time between commencement of heating of the thermoelectric generator and operation of the electroresponsive control device to operating position.

4. Thermoelectric control means according to claim 1 wherein the resistor means is adjustable and by its adjustment acts to adjust both the interval of time between cessation of heating of the thermoelectric generator and operation of the electroresponsive control device to safety position and the interval of time between commencement of heating of the thermoelectric generator and operation of the electroresponsive control device to operating position.

5. Thermoelectric control means according to claim 1 wherein the resistor means comprises a first resistor for reducing the interval of time between cessation of heating of the thermoelectric generator and operation of the electroresponsive control device to safety position, and a second turn-on time adjustment resistor in series circuit relation with said first resistor.

6. Thermoelectric control means according to claim 1 wherein the resistor means comprises a first resistor for reducing the interval of time between cessation of heating of the thermoelectric generator and operation of the electroresponsive control device to safety position, a second turnon time adjustment resistor in series circuit re- 8 lation with said first resistor, and means for completing a circuit including the thermoelectric generator with said second turn-on time adjustment resistor shorted out of said circuit when electric power is applied to the electroresponsive control device.

7. Thermoelectric control means according to claim 1 wherein the second means comprises a coil in the first circuit and a pair of contacts under control of said coil and wherein there is a second pair of contacts under control of said coil and operable to include the resistor means in circult with the thermoelectric generator and the first means and to complete the circuit through the thermoelectric generator and the first means around the resistor means.

8. Thermoelectric control means according to claim 1 wherein electric current is supplied to the first means from the first circuit and the thermoelectric current established by heating of the thermoelectric generator acts in opposition thereto.

RUSSELL B. MATTHEWS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,880,871 Denison Oct. 4, 1932 1,893,847 Simpson Jan. 10, 1933 1,912,798 Sickles June 6, 1933 2,357,609 Ray Sept. 5, 1944 2,366,774 Eskin Jan. 9, 1945 2,384,696 Ray Sept. 11, 1945 2,406,925 Strobel Sept. 3, 1946 2,407,438 Newman Sept. 10, 1946 2,408,954 Ray Oct. 8, 1946 2,479,779 Ray Aug. 23, 1949 2,493,889 Matthews et a1 Jan. 10, 1950 2,513,578 Mathews July 4, 1950