US2386648A - Control device - Google Patents

Description

Patented Oct. 9, 1945 *UNF-rizo-l sTA'rES "PATENT OFFICE *Y CONTRO/L, DEVICE Fred B. Aubert, Grosse Pointe, Mich.

This invention relates to new and useful improvements inelectric circuits andmore particularly tosuch control by means' Vof gaseous fuel burners. l

. Although the electrical characteristics o f a flame haveheretofore been utilized in the control of. electric circuits,` it has been found that lwhen the burner control flame is created by gaseous fuel that'theA controlling operation is critical and thatthe circuit must be balanced or calibrated for different gaseous fuels.' It has been found that this is due to the fact that in some instances the electron mass of the outer envelope of a gaseous flame willl be definitely positive whereas with other gaseous flames the electron mass of the outerY envelope will be definitely negative. It vis therefore one object of this invention to provide a control'which will not be affected by the electrical characteristics ofthe'fuel. l

Another object is to provide afcontrol which is particularly adapted for use with the burner of a heating apparatus.

The invention consists in the improved construction and in the combination of parts ofthe novel control tobe more fully described hereinafterand novelty-of which Willbe particularly pointedjoutand distinctly claimed.

In `theaccompanying Idrawing K to be taken as part of thisuspecication there are fully and clearly .inustmted several; preferred embodiments rReferring to the drawing by. charactersdv of refg-fV erence, I designates generally a fluidfuel burner such as an-oil burner lhaving .an air tube or duct 2 and afuel, feed line; 3terminating in" afspra'y nozz1e 4 positionedpwithin the ductv 2.; A fan Vor blower 5 is connected to the duct 2' to discharge l t air therethrough vto formacombustible mixture with fuel, such as oil discharged from the nozzle 4 by the' pump-,6 whichis intercalated in the fuel line 32 The, fan 5 and pump Baare'driven by an electric-motor 'I whichmay be provided with'an' electrically vor f `electrof-,magneticallyl operated svi/itchv control 8.' AIn seriescircuit withfht-,ly electric Application Maren 7, 1942, serial 433,705

` 15 claims. (c a v actuator and switch contacts ofthe control 8 l. 15s-L28) there is a relay switch 9 having an armature carried contact I0 connected by a lead wire I I to the control 8. The fixed contact I I of the switch 9 is connected by a lead wire AI2 to the 'current supply line ,wire I3, the other supply linewire I4 being connected to the free terminal of the control 8. The primary I5 of a step down transformer I6 is connected by a lead wire I1 to the lead wire I2 yand is connected by lead wire I8 to the supply wire 'I 4. The transformer secondary having turns I9 and .20 supplies the relay coil 2| of switch 9 and also the electricalnetwork of the electron tube 22 to be described hereinafter.

The igniting-rneans for the main burner I comprises a pair of pilot burners 23, 24 havingtheir single outlets directed so that the fuel streams discharging therefrom impinge againstA each other. The burners 23, 24 are further positioned adjacent the main burner I so that the flames of the impinging fuel streams are united to provide an igniting flamel in the path of the combustible mixture discharged from the duct 2V and nozzle 4. The pilot burners 23, 24 are fed with gaseous fuel from branch supply pipes 25, 26 which may support the respective pilot burners and which are fed from a common supply pipe or conduit 21. The-burner 23 has. a supporting base 28 secured and sealed to the pipe 26 and carrying a mixing tube formed by a tubular portion 29 of electric insulating material and an electrical conducting cap ring element 30 of metal positioned at the Vburner tip. The tube portion'ZS is provided with' electrical conductor and forming'the burner mixing tube. Air inlet 34, of which there may be one or more are provided through the member 33 so that there will be proper mixture of air with the fuel discharged from the burner 24. Positioned adjacent the outlet of the burner 24 there is an electrical sparking means 35 such as a spark plug f having spark electrodes 36, 31 to provide a high tension spark for igniting the fuel supplied'by the burner 24. The plug 35 is supplied with high tension currentfrom an ignition transformer 38 f having one side of its secondary 39 connected by a lead wire 40 to the electrode 36. Theother electrode 31 is connected by a lead Wire 4I to the armature carried contact 42 of a relay switch 43,

the fixed contact 44 of switch 43 being connected by a lead wire 45 to the free terminal of the transn former secondary 39.

The relay coil 46 of switch 43 is in series circuit with the solenoid coil 41 of an electrically operated fuel valve 48, one terminal of coil 46 being connected to one terminal of coil 41 by a lead wire 49. The other terminal of relay coil 46 is connected by a lead wire 59 to the xed contact I of a control switch 52 having a movable contact 53 and which may be a room thermostat or other automatic switch responsive to the output of the main burner I. switch contact 53 is connected by a lead wire 54 to lthe secondary 55 of a step down transformer 56 which has its primary 51 connected across the lead wires I3, I4. terminal of the transformer secondaryr55 a lead wire 51a connects to the free terminal of the solenoid coil 41. transformer 38 is also connected across and fed from thelead wires I3, I4. l The `electron tube v22 which, for example, may b'ezof the type known on the market as the No. .iobiiiaciotron has the usual electrodes 59, tu, being respectively the anode and the cathode. Inte'i'posed between the tube electrodes there is a screen grid 6I vand a control element or grid S2. The usual filament` e3 isprovide-d for heatingr tbe cathode. A lead wire 64 connects from one terminal o'f tlie filamentv 53 to one end of the transformer secondary 2 0, from the other end of which lead wire 65 `connects to the other side of the filament to complete its circuit. The cathode -B'is connected by alead 'Wire as to theiead' wire 85; YFrom 'the anode, a lead wire 61 connects to the relay coil 2lU and from the other coil'terininal a -lead'wire 58 connects to the free eh'd of the transformer secondary I9. From the burner tip conducting member 30 a lead wire 69 extends vto the control grid' of the burner controlling electrically operable 'switch 'means comprisingth'e ltube 22 and relay 9. From the electri'ca'liy conductive burner tube a lead wire 'm connects to ground. Connected between the leadvlire 1I of vthe screen grid 6I and the fila'- inentvlead wire 64 there isa `condenser 12 which, for may have a, 'Capacity of 200 mmf. Connected between the lead wires II and 69,

there is a condenser la having a oapaeity which,

for aix-ambie, maybe 50 mmf..

'The oeeration of the heating apparatus of Figs. l and 2, assuming that the current supply to leadfwires I3, I4, 4the gaseous fuel supply to the valve 48,a1d-the liquid fuel supply to the pump 5 l'f available, iS "s Ol-IOWSZ When the Switch 52 is-closed,as by a cal-l for temperatureincrease, theflay coi-l 49 and the solenoid coil 41 are each'energizeol by `oornpletio'n o'f the following circuitgef-rom the transformer secondary 55 through `l'e'ad wire 54, closed switch contacts 53, 5I, lead wire '50, to one terminal of lcoil 46, from thev other coil terminal through lead wire 49 to 'one terminal the solenoid coil 41 and thence from the other terminal of coil 41 Via lead wire 513. back to the transformer secondary 55.` The valve 48 is thus opened by the coil 41 andthe relay switch 43 is cl'o'se'd at contacts 42,

4-4 to complete the Acircuit of the spark plug 35,

which circuit is as follows: From the ignition transfer-mersecondary 39 through lead wire 45 and switch contacts'44, 42 to lead Wire 4I and one electrode 31 of the plug and thence across thel spark gap to the other electrode 35 and via lead wire '49 `to the other terminal of the transformer secondary 39. The gaseous fuel supplied The movable From the other through the conduit 21 from the open valve 48 will mix with the air supplied to the burners 23 and 24 so that the fuel mixture discharging from the burner 24 will be ignited by the spark at the air gap of electrodes 36, 31. The flame of burner 24 will immediately ignite the fuel mixture discharging from burner 23. The substantially equal size impinging flames from these burners will bridge the gap between the terminals of the wires 59 and 1U at their connections to these burners and will therefore establish the circuit from the control grid 62 via lead wires 69 and IIBV to ground. Since the pilot burners are sup- The primary 58 of the ignition rplied with the same kind of fuel and provide llames of substantially equal size, the impinging flames will .provide a path of Aconstant current flow or of the same resistance to current flow irrespective of the type or kind of gaseous fuel employed', because connecting positive to positive ame envelopes or negative to negative flame envelopes results in the llame Contact establislfiing lthe maximum resistance which can be had across the flame path. This flame completed circuit willrender the control grid 62 more positive so that the tube 22 will be energized and rendered capable of current flow to complete the circuit through the relay coil 2| from the transformer secondary I. Energization of oeil 2| will vClose the switch `contacts IG, IIa to complete the circuit through the motor control means or switch B so that air anu vfuel will be supplied by the fan 5 and pump 6 respectively to provide a combustible fuel mixtureI to be ignited by the implng'ing burner flames discharging from the pilotbu'rners 23, t will be apparent that should the flames issuing from the burners 23, 24 fail, or either of them, or should -the flames not imping'e each other, the control grid circuit to ground will'be broken and the t'ube 22 thereby deeriergized, which will stop operation of the burner I by the opening of "switch 9 and the deenergization of the burner controlling switch means.'

Referring, toFig. 3, the lead wires I2 and I8 from the line wires 'I8 and I4, respectively, are connected to the prim-ary 15 of a step down transformer 16 having a center-tapped secondary 11-. The end termi-nails of 'the secondary 11 are co'r'mectedby lead ywires 18, 19 to the anodes 8U,

8| of a full-wave rectifier tube 8'2 having a cathode 83. The-electrical ntwork iS the'usual rectifier circuit having the cathode lead wire 84, which i'S grounded, Cnh'td by a rsistance 10a-d 85 to a lead wire 86 from the center tap of the transon `each side of the choke coil 81 The lead wire 86 "is connected 'at Aits free 'end as ateo to one of the lamination-sof a Rochelle salts warping crystal or control element'Bl. The other lamination ofthe crystal 9i is connected to the flame `lead wire 69 of- Fig. 1,'so'thfat the burner controlling electrically operable switch means comprising the crystal y9| may be' connected to ground through the` impinging pilot flames. Upon subjectin'g the crystal lamination connected to the lead wire 86 to a continuous unidirectional potential, effected by the full wave rectification, the crystal warps or bends to actuate a movable insulatedfswitch contact 92 into closing engagementA with a fixed switch contact 93 to ycomplete a high voltage electric circuit from the line -wires I3, I4 to and through the motor control switch 8," the contact T92 being connected bya lead wire 94 to thelead *.Wire 'l3lan'd1` the contact -93 being connected tothe control switch 8 by lead wire 95.V

*The .operation ofthe heating apparatus when provided withthelcircuit arrangement. of Fig. v3

will, it is believed, be apparent from the foregoing description of Fig. 1 andof the circuit Yof Fig.13. However, it may be noted that the resistance load 85isfsuch that the tube 82 Will b'e maintained energized at all times so that immediatelyupon impingement of the names from the burnersf23,` 2d, a circuit to ground is completed throughthe impinging flames so that a continuousunidirec'- tionalvoltage Willbe applied tothe crystal'Sl which' will warp andclose the relay contacts 92, 93, thereby placingth'e-burner; I inoperation. v

1 It will be apparent that the burnerl I has v been shown asa liquidfuel burner solely for the -purv pose of illustration and that itmaylbe augaseous fuel burner havingv an v electrically"operated or solenoid valve positioned inthe burner'gvas lineY in lieu of the control .switch 8 and motor 1.

yHaving thus described fthe invention, 'what is fclaimed and is 'desired to be securedfby YLetters Patent ofthe United States is:

1. lA control devicecomprising a plurality of gaseous fuel burners so constructed and arranged that a fuel stream discharging from one of said burners impinges against alfuel stream discharging from another of said `burners, means to'produce flame sizes substantially equal to each other at said burners and tosupply said burners VvWith `the same kind of gaseous fuel, a control means, an electrical' conductor operable to connect the flame of one of said burners to said control means, and an electrical conductor to connect the flame of theother of said burners to ground, the impingement of said flames closing thel circuitbe tween said conductors thereby-to render rsaidY control means effective. 'Y o 2L Acontrol device comprising a plurality `-of gaseous fuel burners so constructed and arranged that a fuel stream discharging from one Vvof said burners impinges against a fuel stream discharging from another of said burners, meansto produce impingingrames of substantiallyequal size at said burners and to supply said burners with the same kindof gaseous fuel,a control means, one of ksaid Aburners having insulating means to electrically insulate its flame "from ground;V an v electrical conductorv to' connect the insulated flame to-said control means, and an'electrical conductor to connectfthe flameof the other of said burners to ground, the impingement of said iiames closing the circuit between said conductors thereby to render `saidcontrol means effective. V3. A control device comprising an electron tube Cil havng electrodes and a control element, va plurality of gaseousfuel burners so constructed and arranged that'a fuel stream'discharging from one of said burners impinges against a fuel stream discharging from another offsaid burners, means to produce impinging flames of substantially equal size at said burners andfto supply said burners with the same kind of gaseous fuel, means operable to electrically connect the flame of one of said'burners to said control element, means to electrically insulate the flame of said last-named one of said burners from ground, and meanstolelectrically connect the'fla'me of the othenof' said burners 'to groundtthe impingement of'saidiiames closing the circuit between said conductors thereby to controlthe op eration-@risata tube-l- 1 -f 2.4. `Acontroldeviceicomrirising a Rochelle salts control element, meansztos'upply 'a unidirectional continuous Apotential to one side of sai'd'felement, a pluralityofgaseous fuelburners so constructed and arranged that a fuel stream discharging fromV oneV of said burners impinges against av fuel stream discharging from another of` said burners, means to produce impinging names .of substantially equal size at said burners andl tosupply said burners with the same kind of gaseous fuel, means operableY to electrically connect theflame of one of said burners to the other side ofsaid control element, means to/electrica'lly insulater the flame of said last-named one of saidburriers from ground, and means to electrically connect the ame of the other of said burnersto ground,

the impingement of said flames subjecting said` control element to said continuous potential` thereby to actuate said control element.

5. A control device comprising anelectron tube having electrodes and a control element, a burner having atube portion of electric'insulating -ma-z'4 terial, an electrical conductor carried vby'saidtube` portion and positioned for conductingY relation with the burner ame, a burner having agroundg ed tube portionof electric conducting material in conducting relationwith its burner name, said burners having a fuel discharge of one burner di-l rected against a fuel' discharge from the other burner, means electrically connecting saidacon-r ductor to said control kelement so that said elec-` tron tube will be'capable ofcurrent iiow bysim-` pingement of the burner amesyand means-to Supply the same kind of -gaseous fuelto 'eachofsaid burners vand .to provide substantiallyequal flame sizes at both burners so that apathiofl constant current iiow Will be' established by the impinging flames.

6. A control device comprising aplurality'of gaseous fuel burners, one of said burnerslbeing constructed and arranged to discharge algaseousi fuel stream in impinging relation to a gaseous fuel stream discharged from another of said :burners, means operable to electrically connect the flame of one of said burners to ground, means to electrically insulate the flame of the Lother ofl said` burners from ground, means vto produce flames of substantially the same size atg'said one and said other burner, an electrical conductor adapted to be in electric conducting relationfto the ame of said last-named'other of said burners,l an electron tube having a circuit controlled therebyand having a control element electrically connected to said electrical conductor, and aconduit for supplying the same kindof gaseous fuel to each of said burners so that thesubstantially equal sizevimpinging flames'will provide a path of constant current ow irrespective'of the kind of fuel and Will electrically connect said control element to ground, thereby to render said tube conducting. 7

7. A control device comprising Va plurality of gaseous fuel burners, one of said burners being constructedand arranged to discharge'a gaseous fuel stream in impinging relation to a gaseous fuel stream discharged from another of said burners, means operable to electrically `connect the flame of one of said burners to groundfmeans to electrically insulate the flame of they other of said burners from ground,` means to produce ames of substantially the same size at saidone and said other burner, an electrical'conductorr connected to said electrical conductor, a conduitr for supplying the same Vkind of :gaseous fuel to each of said burners, and electric sparking means for igniting the fuel discharged from Ysaid last'- named one of said burners thereby toA ignite the fuel discharged from said last-name`dcther of said burners.

8. A burner control device comprising a main fuel burner, mea-ns controlling the supph7 of fuel to said burner, a yplurality of gaseous fuel pilot burners at least one of which has fa fuel stream directed to ignite the fuel discharged from said main burner, said pilot burners being so con-r structed and arranged that a fuel stream dis'-Y charging from one of said pilot burners impinges against a fuel stream discharging from `another of said burners, means to supply said pilot burners with the same kind of gaseous fuel vand to produce flames of substantially equal size `at said pilot burners, yelectrically operable switch means controlling the operation of said .burner controiling means, means to ignite the fuel discharging from said pilot burners so that there will be ime pinging flames, means to electrically connect the flame of one pilot burner to said switch means, electric insulating means interposed between said connecting means of said last-named one pilot burner and ground, and means to electrically connect the name of said other pilot burner to ground so that said switch means will be energized by impingement of the pilot burner flames.

9. A burner control device comprising a main fuel burner, means controlling the supply of fuel to said burner, a plurality of gaseous fuel lpilot burners at least one of which has a fuel stream directed to ignite the fuel discharged from said main burner, said pilot burners being so constructed and arranged that a fuel stream discharging from one of said pilotburners impinges against a fuel stream discharging fromanother of said burners, means to produce impinging flames of substantially equal size at said burners and to supply said pilot burners with thesame kind of gaseous fuel, Aan electron tube having 4a circuit controlling said burner controlling means and having a control element, means to ignite the fuel discharged from one of said pilot burners thereby to ignite the fuel ydischarge-d from the other of said pilot burners, means to' electrically connect the dame of said lastenamed other pilot burner to said control element, electric insulating means interposed between ysaid connecting means of said last-named other pilot .burner andv ground, and means to electrically connect the flameof said last-named one .pilot burner to ground so that said electron tube will be capable of current flow by impingement of the pilot burner flames.

10. A burner control device comprising a main fuel burner, means controlling the supply of fuel to said burner, a plurality of gaseous fuel pilot burners atleast one of which has a fuel stream directed to ignite the fuel discharged from said main burner, said pilot burners being 'so 'cone structed and arranged that a fuel stream discharging from one of said pilot .burnersimpinges against a fuel stream discharging fromnanother of said burners, means to produce .impinging flames of substantially equal size at said .burners and to supply said pilot burners with the same y kind of gaseous fuel, an electric switch controlling the operation of said burner controlling means, a warping crystal yoperable to actuate said switch, means to supply a unidirectionalcontinuous lpotential to one side of said crystal, means to ignite the fuel discharged from oneof said. pilot burners thereby to ignite the fuel discharged from the other of said pilot burners,means to electrically Vconnect the flame of said last-named other pilot burner to the other side of said crystal, electric insulating means interposed between said connecting means 'of -said last-named other pilot burner and ground, and means to electrically connect the `flame of said lastenamed one pilot burner to ground so that said crystal will be warped upon impingement of the pilot burner flames.

1l. A burner control device comprising a main fuel burner, a vplurality of pilot burners operable to produce flames of substantially equal size and so related that their respective flames 'will impinge eachother, means 'to supply the same kind of gaseous fuel to said pilot burners, at least one of said pilot burners being so related to said main burner that the flame `of said one pilot` burner can ignite the fuel supplied to said main burn-- er, an electron tube having a 'control grid with a controlling circuit, means forming a series gap in said grid circuit and .positioned to be .bridged by the impinging pilot burner flames, and means controlling the initial supply offuel to said main burner and controlled by said tube, said tube being rendered effective upon completion of said grid circuit by the impinging pilot flames.

12. A burner control device comprising a main fuel burner, a plurality of pilot burners so related that their respective flames will impinge each other, at least one of said pilot burners being so related to said main burner that the flame of said one pilot burner can ignite the fuel supplied to said main burner, warpable means having a circuit controlling its operation, said circuit having spaced terminals providing a gap to be bridged by the impinging pilot burner flames, and means controlling the initial supply` 'of fuel to said main burner and controlled by said warpable means, said controlling means being rendered effective upon completion of said circuit by the impinging pilot flames.

y13. A burner control device comprising a main fuel burner, electrically operable fuel supply means for said burner and having a circuit, a normally open switch controlling said circuit, electrically energized means operable to close sai-d switch, a pair of pilot burners so positioned that their respective flames will impinge each other, at least one of said pilot burners directing its flame to ignite said main burner, means to produce substantially equal flame sizes at said pilot burners, means to supply thesame kind of gaseous fuel to each of said pilot burners, said electrically energized means having a controlling. circuit, said pilot burners being positioned in series in said controlling circuit and being spaced to provide a series gap in said controlling circuit, and means to .ignite the fuel supplied to said pilot burners to provide impinging flames bridging said gap thereby to complete said controlling circuit for closure of said normally open switch.

14. A burner control device comprising a main fuel burner, electrically operable fuel supply meansfor said burner and having a circuit, a normally open switch controlling said circuit, electronic means oper-able to close said switch, a pair of pilot burners so positioned that their respective flames will impinge each other, at least one of said pilot burners directing its flame to ignite said main burner, means to produce lsubstantially equal flame sizes at said pilotburners, means to supply the same kind of 'gaseous fuel to each of said pilot burners, said electronic means having a `grid controlling circuit, said pilot burners being positioned in series in said grid controlling circuit and being spaced to provide a series gap in said controlling circuit, and means to ignite the fuel supplied to said pilot burners to provide impinging flames bridging said gap thereby to complete said controlling circuit for closure of said normally open switch.

15. A fluid fuel burner safety starting means comprising a pair of pilot burners directed relative 'to each other for flame impingement and electrically insulated from each other to provide a circuit gap, means to supply the same kind of that the impinging llames will complete said con-v trolling circuit thereby to render operation of said electrically controlled switch closing means dependent upon impingement of said pilot burner flames.

FRED B. AUBERT.

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