US3260301A

US3260301A - Igniter

Info

Publication number: US3260301A
Authority: US
Publication date: 1966-07-12
Anticipated expiration: 1983-07-12

Description

July l2, 1966 R. J. zoscHAK ETAL 3,260,301

IGNITER Filed Feb. 20, 1964 VENTORS OJCHA K 9065er SOMMEFZAQ Bu/n mmf ATTORNEY United States Patent O 3,260,301 IGNITER Robert J. Zoschak, Rutherford, and Robert E. Sommerlad, Cranford, NJ., assiguors to Foster Wheeler Corporation, New York, N.Y., a corporation of New York Filed Feb. 20, 1964, Ser. No. 346,315 Claims. (Cl. 15S- 115) This invention relates to igniters and more particularly to igniters using a gaseous fuel.

In the construction of gas-burning igniters, it is very important to achieve stability of combustion. According to this invention in order to obtain the desired stability, a pilot chamber is annularly disposed within an outer partition. In the space between the outer shield and the pilot chamber, a passageway is formed for supplying air to the llame port and for locating a series of individual conduits which delivered combustible gas to the flame port. Apertures in the pilot chamber permit a limited quantity of air from the passageway to enter the pilot chamber. An orifice plate at the outboard end of the pilot chamber permits only a limited quantity of combustible gas to enter the pilot chamber.

Also important in the construction of igniters is to provide for long life for preventing the heat of the burner -being ignited from deteriorating such heat destructible parts of the igniter as the pilot ignition system. In accordance with this invention, this is achieved by locating such parts as remotely as possible from the burner heat. Such remotely located parts also provide for easier maintenance of the igniter.

An object of this invention is to provide an improved igniter.

` Another object of this invention is to provide an igniter withv stability of combustion.

Still another object of this invention is to provide an igniter which avoids deterioration from burner heat.

kend of the apparatus embodying the invention joined on the lines a-a of FIGURE 1.

FIGURE 2 is a transverse section taken on line 2-2 of FIGURE 1.

FIGURE 3 is an inboard end view of the apparatus embodying the invention.

Referring now to the drawings and particularly to FIG- URE 1, the igniter has an outboard portion, generally designated by the numeral 11, which is located outside a furnace or other burner enclosure (not shown). The igniters inboard portion, generally designated by the numeral 12 and shown in FIGURE 1A, is located inside a furnace. The inboard portion 12 has a flame port 13 located at its extreme inboard end. The igniter passes through a wall (not shown) of the furnace and is so placed that the llame port 13 is adjacent the burner of the furnace. In this way the apparatus serves to ignite combustible fuel when it is emitted from the burner.

An outer partition 14 forms the outside surface of both the outboard portion 11 and the inboard portion 12 of the igniter. A shell 18 encloses the extreme outboard end of the outboard portion 11. A flange 15 is connected to the shell 18. A similar flange 16 is connected to the outer partition 14. A plate 19 ts between the flange 15 and the flange 16. The

flanges

15, 16 are pressed against the plate 19 by means of bolts 20. Seals 21 are used rice between the plate 19 and the

flanges

15, 16 to prevent leakage. A gas inlet 23 opens into the shell 18 which defines a gas-collection compartment 25.

Within the outer partition 14 is a inner partition 27 which, as shown in FIGURE 1A, is withdrawn slightly within the outer partition 14 at the llame port 13. The space encompassed by the inner partition 27 defines a pilot chamber 28 which is open at the flame port 13. The opposite end of the inner partition 27 has an orifice plate 29 secured to it. Orifices 31 provide multiple small passageways through the orifice plate 29. The total crosssectional area of the orifices 31 is controlled by the amount of combustible fuel desired within the pilot chamber 28 formed by the inner partition 27. A cyclindrical lip 32 protrudes from the orifice plate 29 thereby defining a threaded cavity 33. A plug 35 is screwed part-way into the threaded cavity 33 to leave a space 37 between the plug 35 and the orifice plate 29. A threaded opening 38 is located through the center point of the plug 35.

Located approximately at the center point of the end plate 19 is a threaded opening 40. Threaded into the opening 40 is a bushing 41 which secures a pilot gas-supply tube 43 to the plate 19. The opposite end of the pilot gas-supply tube 43 is screwed by means of a fitting 45 to the threaded opening 38 in the plug 35. The pilot gas-supply tube 43 thereby defines a passageway cornmunicating between the gas-collection compartment 25 and the space 37 between the plug 35 and the orifice plate 29.

An annular space 39 is located between the inner partition 27 and the outer partition 14.v yA series of tubes or conduits 48 pass through the space 39 and extend beyond the outer partition 14 as shown in FIGURE 1A. At the flame port 13 the4 conduits 48 are bent, and the llame orifices 52 are attached. The opposite ends of the conduits 48 pass through threaded openings 42 in the end plate 19. Bushings 44 are screwed into the openings 42 to seal the connection between conduits 48 and the end plate 19. U-members 46 are circumferentially placed in a spaced relation to assure separation between the conduits 48. As gas is supplied into the compartment 25 through the gas inlet 23, a major portion of the gas flow passes through the conduits 48 and a minor portion of the flow passes through the tube 43 to the pilot chamber 28. The bend at the inboard end and the orientation of the conduits 48 causes the combustible gas being discharged fmom the conduits 48 at lthe flame port 13 to swirl inwardly.

An air inlet 47 is provided through the outer partition 14. Large apertures 49 are provided in the inner partition 27 to permit a minor portion of the air flow to enter the pilot chamber. A major portion of the air stream flows through a number of passageways 50 which are formed from the portion of the annular space 39 not occupied by the conduits 48. An adjustable sleeve 51 may be provided having perforations 53 therein to regulate the cross-sectional area available for the flow of air through the large apertures 49. Use of a sleeve 51 as well as the number and sizing of the apertures is, of course, a matter of choice. Small apertures 55 are provided in spaced locations about the circumference of the inner partition 27 to provide additional air to a flame in the pilot chamber 28 as the flame approaches the llame port 13.

A spark plug 57 is provided which extends into the pilot chamber 28 to provide a spark therein for ignition of a pilot flame. A sight port 59 is located in line with an aperture 61 which is one of the group of small apertures 55 to permit viewing into the pilot chamber 28 through a transparent sheet 62.

In operation, combustible gas is supplied through gas inlet 23 into compartment 25. A major portion of the gas flow passes into conduits 48 which deliver the gas directly to the flame port 13. The bent ends and orientation of the conduits 48 swirl the gas streams inwardly. A minor portion of the gas passes through tube 43. Air is supplied through air inlet 47. A major portion of the air flows through passageways 50 between the conduits 48 to llame port 13. A minor portion enters the pilot chamber 28 through the

apertures

49, 55. When the spark plug 57 is electrically charged, a spark lire-s the gas and air mixture in the pilot chamber 28 and the flame in the pilot chamber 28 burns continuously through the full length of the inner partition 27. As the ame progresses toward the llame port 13, additional air continues combustion. This additional air which enters through the various apertures 55 is necessary to completely burn all the ga-s entering the pilot chamber 28 since the amount of air entering through the apertures 49 is inadequate for full burning of the gas being supplied through the orices 31. The pilot llame emerges from the pilot chamber 28 igniting the gas and air being discharged at the llame port 13. As soon as the spark begins burning in the pilot chamber 28, the spark plug S7 need no longer be electrically charged. The flame thus burning at the flame port 13 serves to ignite a burner located nearby.

It is to be understood that the above-described arrangements are simply illustrative of the application of the principles of the invention. Numerous other arrangements may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.

What is claimed is:

1. An igniter for fuel burners comprising:

an outer partition defining a llame port at one end,

an inner partition with apertures therein located within said outer partition so that an annular space is formed between said inner partition and said outer partition and a pilot chamber is formed within said inner partition,

conduits occupying a portion of said annular space,

means for introducing combustible gas to said conduits and to said pilot chamber,

means for limiting the portion of combustible gas flowing into said pilot chamber so that a major portion of said combustible gas flows through said conduits to said flame port and a minor portion of said combustible gas flows into said pilot chamber,

an air inlet for introducing air, said air flowing through said annular space around Isaid conduits, a major portion of said air being discharged from said annular space at said llame port and a minor portion entering said pilot chamber through said apertures, and a sparker in said pilot chamber to cause a pilot llame to burn in said pilot chamber, said pilot flame causing the combustible gas llowing from said conduits to burn at said llame port.

2. An igniter according to claim 1 wherein:

said conduits extend beyond said outer and inner partition and are arcuately shaped at the flame port so as to swirl the combustible gas as it is discharged therefrom.

3. An igniter according to claim 1 wherein:

said outer partition extends slightly beyond said inner partition at said llame port, and

said conduits extend beyond said outer partition, the

extending portions being arcuately shaped.

4. An igniter for fuel burners comprising:

an outer partition having an inboard end and an outboard end, said inboard end defining a flame port,

an inner partition with apertures therein located within said outer partition so that an annular space is formed between said inner partition and -said outer partition and a pilot chamber is formed within said inner partition, said inner partition having an inboard end and an outboard end,

a shell forming a compartment at the outboard end of said outer partition,

an inlet for introducing combustible gas into said shell,

conduits extending from said compartment through said annular space to said flame port to provide a passageway for said combustible gas,

an orifice plate between said compartment and said pilot chamber for limiting the portion of combustible gas llowing into said pilot chamber so that a major portion of said combustible gas flows through said conduits to said llame port and a minor portion of said combustible gas ilow-s into said pilot chamber,

an air inlet for introducing air, said air flowing through said annular space and around said conduits, a major portion of said air being discharged from said annular space at said flame port and a minor portion entering said pilot chamber through said apertures, and

a sparker in said pilot chamber to cause a pilot flame to burn in said pilot chamber, said pilot flame causing the combustible gas flowing from said conduits to burn at said llame port.

5. An igniter according to claim 4 wherein the outer partition and inner partition are concentric cylinders.

References Cited by the Examiner UNITED STATES PATENTS 12/1964 Ihleneld 158-109 X 2/1965 Zoschak 158--115

Claims

1. AN IGNITER FOR FUEL BURNERS COMPRISING: AN OUTER PARTITION DEFINING A FLAME PORT AT ONE END, AN INNER PARTITION WITH APERTURES THEREIN LOCATED WITHIN SAID OUTER PARTITION SO THAT AN ANNULAR SPACE IS FORMED BETWEEN SAID INNER PARTITION AND SAID OUTER PARTITION AND A PILOT CHAMBER IS FORMED WITHIN SAID INNER PARTITION, CONDUITS OCCUPYING A PORTION OF SAIDF ANNULAR SPACER, MEANS FOR INTRODUCING COMBUSTIBLE GAS TO SAID CONDUITS AND TO SAID PILOT CHAMBER, MEANS FOR LIMITING THE PORTION OF COMBUSTIBLE GAS FLOWING INTO SAID PILOT CHAMBER SO THAT A MAJOR PORTION OF SAID COMBUSTIBLE GAS FLOWS THROUGH SAID CONDUITS TO SAID FLAME PORT AND A MINOR PORTION OF SAID COMBUSTIBLE GAS FLOWS INTO SAID PILOT CHAMBER, AN AIR INLET FOR INTRODUCING AIR, SAID AIR FLOWING THROUGH SAID ANNULAR SPACE AROUND SAID CONDUITS, A MAJOR PORTION OF SAID AIR BEING DISCHARGE FROM SAID ANNULAR SPACE AT SAID FLAME PORT AND A MINOR PORTION ENTERING SAID PILOT CHAMBER THROUGH SAID APERTURES, AND A SPARKER IN SAID PILOT CHAMBER TO CAUSE TO PILOT FLAME TO BURN IN SAID PILOT CHAMBER, SAID PILOT FLAME CAUSING THE COMBUSTIBLE GAS FLOWING FROM SAID CONDUITS TO BURN AT SAID FLAME PORT.