US2634807A - Gas fueled igniter - Google Patents

Description

April 14, 1953 R. H, FORNEY 2,634,807

' GAS FUELED IGNITER Filed NOV. 18, 1949 2 SHEETS--SHEET 1 Tumbler, swffch Juncffon fff INVENToR.

50X Ross H. Forney /0 nl' AC, fupp/y ATTORNEYS April 14, 1953 R H FORNEY 2,634,807

GAS FUELED IGNITER Filed NOV. 18, 1949 2 SHEETS-SHEET 2 JNVENTOR.

Rass H Forney ATTORNEYS Patented Apr. 14, 1953 UNITED STATES PAT-ENT OFFICE GAS FUELED IGNITERY Rossk H. Forney, Dallas, Tex. f

Application November 18, 1949; Serial No.2128;109 (Cl. 158-115) 2 Claims.

This invention relates to new and useful improvements in means for igniting pilot burners.

A particular object of the invention is to pro-V ignited by a spark, resulting in ignition of the wherein an example of the invention is shown,

and wherein:

Fig. 1 is a View in perspective taken from the outer side of the furnace wall and illustrating a pilot burnerV ignitorY constructed in accordance with this invention,

Fig. 2 is a longitudinal, vertical View of the pilotburnerand the main furnace burner., .the

view being partially broken away,

Fig. 3 is an enlarged sectional view of the.ex..

plosion chamber, and

Fig. 4 is a schematic wiring diagram of .the electricalfportion of the invention.

In the drawings, the numeral VII) designates the'wall of a furnace flrebox, and the numeral I I,

the usual secondary or protective wall `carrying the burner fittings. bly I2 is positioned inthe wallr II and extends into the furnace. iirebox through the Wall IIB.

A main burner tube assem;

This structureisusual and customary and does notforma portion of the present invention.

A..pilot burner. structure, designated generally. f by. the numeral I3, is also mounted inthe wall I I 1 and extends into .the furnace above the burnerV structure I2 for the purposeof providing a pilot amefor igniting. or maintaining theignition of.v the main burner. The pilot burner structureinfcludesa central gasor combustible fuelconducwtor .I4. extending. axially Vof an .fouter conductor` I5, i the ftwo conductorsfextending,through 3a mounting tube: IB positioned`- in the -Wall II. As shown .inFig v2, thefconductorl is formed'with a plurality of enlarged' sections vI6.y having radial ports I1, and a muille'or shroud'IS is carried upon the'innerfor furnacezendz of :said conductor structure I 5. The'inner conductorzl'extends throughout the lengthof theconductorIS terminating v at; I9 a short'distance-within themuffie.v I8'. A

plurality ofair inlet ports J2Iliare cut inthe closed endof Lthe munie I in the usual manner. i

A mounting plate 2 II.` is .positioned outwardly, ofthewa'llv II, adjacentwth'e router .end `of the` mounting tuberii'.

may be-supported in any suitable fashion. At the outerendof the'conductors I4an'd I5,an explosion or ignition fitting 22 is provided'. The fitting 22 iselcngate in shapevand is provided witha stepped internaL'axialpassag-e `23fextending from the forwardk end thereof to a point adjacent the f rearward portion of said vfitting; The rearmost portion l2131 ofI the passage' 1-23is relatively small. in diameter and carries screw-threads 25receiv' ing the screw-threaded-rearward end 26 of the pipel'IlSaiV A lateral vbranch passageA 21/ communicates with the portion 24` and is screw-threaded to rreceive a conductor 28- extending laterally from therea-rward portion of the fitting 22.1

Forwardly of the'screweth-reads 25,- the passage-23 is enlarged to 4form a counterbore 29 and provide an annular space3llabout the rearward portion of the-pipe III. A secondxlateral'passage 3I'venters the'fitting 221 forwardly of4 the space 3D and communicates with Sa lsecond counterbore or.` enlargement'. 32; of :the :passage 23.. The passageV 3 I Vis 'screw-threadedftov receive a conductor 33 extending laterally from theiittinguZZ, and the second...counterbore.` 32` is also-.provided .with interna'lrii screw'-y threads receiving i the` screwthrea'd'ed' rearward end 34. of `:thee pipe II 5. With this arrangement,l communication; is hadv through thepipegS-with the interiorof the pipe: I'5, while communication `is Ihad through" Athe pipe: 2B with'V the vinterior. of the pipe I4.

Fuel .gas for. the: pilot: burnerjs normally4 sup..

pliedthrough thefconductor 28, and for this purpose, a gas-supply,pipe35sformsxa part-of `the ap-zy paratus. The pipe 35 is disposed laterally of the pilot arrangement and is. connected through a T 316:1t0- an `elongate manifold 1.37V extending horizontally between :.the ;..shield;l I. and. the mountingiplate` 2 I.; ofcourse; theimanifoldmay i beextended to any desirable -.length sofasto'supV plyggas sito the.. pilot vburners:forzadditional main r..

Ther platet'ZI. .carries thev ignitor controls-to be.describedvhereinafter and furnace burners associated with the burner described. A suitable pressure gauge A38 is connected to the opposite branch of the T 36 for indicating the pressure of the fuel gas supply.

Substantially in vertical alinement with the tube I6, the manifold 31 carries a T 39 into which a branch pipe -40 is connected. A cutoff valve 4| is located in the pipe 4D and also a solenoid valve 42. Outwardly of the Valve 42, a

union 43 is positioned in the pipe 40, the latter terminating in the downwardly directed elbow 44 to which is connected a vertical conductor 45. A T r46 is connected to the lower end of the conductor 45, and a pipe 41 extends downwardly from the T, being connected through a union 48 with the upper end of the pipe 28. Thus, fuel gas may flow from the pipe 3-5 through the varil ous pipe and connections described to the pipe 28, and thence to the pipe or conductor I4.

Air under pressure for combustion purposes is similarly furnished through a supply pipe 49 disposed laterally of the pilot structure and being connected through a T 50 into an air manifold 5I extending parallel to and below the manifold 31. A suitable pressure gauge 5I is connected to the T150. At an intermediate point, the manifold 5| is provided with a T 52 carrying a lateral conductor I53 having therein a suitable cutoff valve 54 and a union 55. An upwardly directed elbow 56 is mounted upon the outer end of the pipe 53 and carries an upwardly extending conductor 51 having an elbow 58 upon the upper end thereof to which is connected a pipe 59 extending parallel to the manifold 5I toward the right hand side of the structure as Viewed in Fig. 1. The pipe 59 is connected into an enlarged T 60 in vertical alinement with the pipe 33, and a conductor 6I extends downwardly from said T to the upper end of the pipe 33, there being incorporated into the pipe 6I a union 62 and a T 63. A pipe or conductor 64 leads from the lateral branch of the T 46 to the remaining branch of the T 60, and in this manner fuel gas as well as air under pressure may be communicated and conducted to the pipe 6| and the T 63.

`Suitable electrical control apparatus is carried pon the supporting plate 2| the wiring diagram for the equipment being schematically illustrated in Fig. 4. A main electrical power supply cable 65 is provided, and supplies electrical power through a junction box 66 to a solenoid circuit 161 and an ignitor circuit 68. The solenoid circuit extends through a tumbler switch 69 to a pilot light 10 and a solenoid armature 1I connected in parallel across said switch. Thus, when the switch 69 is closed, the pilot light 10 is ignited and the solenoid armature 1I is actuated to open the solenoid valve `42.

The ignitor circuit is .connected in series through a push button, momentary contact switch 12 and the primary coil 13 of a high voltage output transformer 14. The secondary coil 15 of the transformer 14 is connected between ground and a spark plug 16 carried in the lateral branch of the pipe T 63. Thus, upon closing of the switch 12, a momentary high voltage is applied to the spark plug 16 which is thereby caused to produce an electrical spark within the interior of the pipe T 63.

In the operation of the device, the valves 4I and 54 are opened to admit fuel gas and air under pressure, and the switch 69 is closed to actuate and open the solenoid valve 42. Fuel gas n'ow ows through the pipe 28 to the pipe I4 and thence to the furnace end I9 of said pipe. Simultaneously, gas fiows through the pipe A64 into the pipe T 63, and through the pipe 33 into the interior of the pipe I5. The air under pressure flows to the pipe 59 and through the T 60 to the T 163 and also into the interior of the conductor I5. An explosive mixture of air and fuel gas is thus present within the T 63, and shortly after opening of the valves, throughout the interior of the pipe I5 surrounding the pipe I4.

The momentary contact switch or push button 12 is now closed which causes the spark plug 16 to function and produce a spark within the T B3. The spark ignites the air and gas mixture, resulting in a rapid combustion or explosion which is propagated throughout the length of the pipe I5 and ignites the fuel gas issuing from the furnace extremity I9 of the pipe I4. The violence of the explosion is somewhat mitigated by the enlarged portions I6 and the ports I1 which relieve the accumulated explosion pressure and provide for a diminishing of any destructive forces resulting from the explosion. The propagation of the flame is not interrupted by these enlarged portions or ports, however, and the ame is conducted to the end I9 of the conductor I4 to ignite the fuel gas flowing therethrough and result in lighting of the pilot burner. Of course, the pilot flame issues from the end of the muiile I8 and functions to ignite the main burner I2 when so desired, or to maintain the ignition of said burner.

Normally, the supply of air is cut oif as soon as the pilot flame is brought into existence, and although some gas may continue to flow through the pipe 54 and the pipe I5, it merely burns within the mufe I8 and is consumed in the pilot flame.

In the event the pilot flame is not ignited upon the first effort, the described operation may be continued any desirable number of times until successful ignition is obtained. In practice, however, it has been found that the present device ignites the pilot flame upon the rst attempt in nearly every case, and the repeated ignition efforts are not required.

When it is desired to extinguish the pilot burner, the switch 69 is easily and quickly opened, resulting in closing of the solenoid valve 42 and the substantially instantaneous shutting off of the fuel gas owing to the pilot burner. This action is much faster, and may be accomplished much quicker than manually closing the valve 4I. Of course, the latter valve may be closed after the pilot lia-me is extinguished in order to provide for a double shut-off of the fuel gas with the enhanced safety resulting therefrom. The pilot light 10 is illuminated at all times the solenoid valve 42 is open and serves to notify the operator of such fact.

It is to be noted that the spark plug 16, and indeed the entire electrical system, are located outside of the furnace and are not subjected to furnace temperatures. The various portions of the electrical equipment will not stand continuous high temperatures, and this provision greatly lengthens the operating life of the equipment by situating it at the outer end of the pilot burner rather than at the inner end thereof. The provision of all of the control devices without the furnace also causes this vinvention to be particu-` larly applicable to the new types of furnaces in which an entire boiler setting is carried under an appreciable pressure. It is almost physically impossible to employ the old type of lighting by means of a hand torch in this new type of furnace because the outward blast of air through an open port through which the hand torch must be inserted would immediately extinguish the torch and prevent the lighting operation being successfully concluded. This is not true with the present invention which contemplates a permanent installation which may be made pressure tight, and in which all manipulations are carried on at a point remote from the combustion chamber of the furnace.

The entire arrangement is very simple and easy to operate and affords great convenience to the tender of the furnace. Since the equipment is always in position and is operable upon a moments notice the pilot burner can be very quickly and readily ignited or extinguished. Further, since all but the burner portion of the pilot is situated remote from the combustion chamber of the furnace, the equipment is not subjected to adverse operating conditions and has an indefinite but extremely prolonged operating life.

The foregoing description of the invention is explanatory thereof and various changes in the size, shape and materials, as Well as in the details of the illustrated construction may be made, within the scope of the appended claims, Without departing from the spirit of the invention,

What I claim and desire to secure by Letters Patent is:

1. A pilot burner and ignitor for furnaces inculding, an elongate tube, an elongate sleeve substantially co-extensive with the tube and sur- 30 rounding the latter throughout substantially its entire length to form a burner and ignitor assembly adapted to be positioned with one end adjacent the main burner of a furnace, a fitting receiving the opposite end of the assembly remote 3 from the burner end thereof, said fitting having a passage communicating with the tube and a passage communicating with the sleeve, means supplying fuel gas to each passage, means supplying air under pressure to the passage cornmunicating with the sleeve, and electrical ignition means communicating with the latter passage adjacent the tting.

2. A pilot burner and ignitor for furnaces including, an elongate tube, an elongate sleeve substantially co-extensive with the tube and surrounding the latter throughout substantially its entire length to form a burner and ignitor assembly adapted to be positioned with one end adjacent the main burner of a furnace, a fitting receiving the opposite end of the assembly remote from the burner end thereof, the fitting having a passage communicating with the tube and a passage communicating with the sleeve, conductor means supplying fuel gas under pressure to each passage, conductor means supplying air under pressure to the passage communicating with said sleeve, and electrical ignition means in the latter conductor means adjacent said fitting.

ROSS H. FORNEY.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 734,201 Thornton July 21, 1903 840,586 Rech Jan. 8, 1907 2,087,433 Hollman July 20, 1937 2,460,016 Kuhn Jan` 25, 1949 2,520,608 Minnich Aug. 29, 1950

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