US2167183A - Gas burner - Google Patents

Description

J y 25,1939. G. F. MAB Em I 2.161.183

4 GAS BURNER Filed Nov. 14, 1936 /e 2d. w, W4 [IT r 177 7 2a! 2a a l 6' 6a 66 d 8 a ab 29 4 2f 3;,

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mu.or All Pl or ze fam 8 t in Fm-a INVENTORS @FQRGEF. NAAB 8- QTTQ LUTHERER Patented July 25, 1939- UNITED STATES GAS BURNER George F. Naab, Iakewood. and Otto Lntherer Solon, Ohio, minors to The North American Manuiacturing Company, Cleveland, Ohio, a

corporation of 1 Ohio Application November 14, 1936, s mi No. 110,890

11 Claims. (cl. its-[110) This invention relates to burners for progressive combustion of natural o1" artificial gas fuels whereby heat is liberated at relatively constant and relatively low temperature in a long luminous flame.

Such burners are known as luminous flame burners and include means providing for a delayed or gradual mingling with the fuel of the air which supports its combustion.

The object of this invention is to'provide improvements in such means for controlling mingling of air and fuel. Further objects are to provide a burner structure of improved simplicity for the purpose, easily assembled, and as easily disassembled for replacement or parts eventually deteriorated by theintense heat generated in service. Another object is to provide an improved pilot or auxiliary for the burner, easily ignitable and allowing easy inspection of its flame, and

arranged for continuous functioning during operation of the burner to maintain combustion in the latter.

More particularly, the invention provides, as will appear, an intimate mingling and gradual merging relation between pilot and main burner flames, the latter being produced by a'gas stream as a core about which the air for its combustion is introduced only progressively in restricted amounts, and the pilot flame is arranged between this core and the first increment of air. Further, air streams are added to the gas stream with parallel motion so as to maintain velocity through the burner yet without accelerating combustion, and the air streams have progressively increasing velocity-all to the end, as further objects of the invention, that combustion will be retarded and the burner flame extended a maximum amount.

The exact nature of this invention together with further objects and advantages thereof will be apparent from the following description taken in connection with the accompanying drawing in which Fig. 1 isa view in typical longitudinal section showing an embodiment of the invention; Fig. 2 is a transverse section of the same as in the planes of line 2-2, Fig. 1;'Flg. 3 is. a mouth end view of the same; and Fig. 4 is an enlarged section as in the plane of-line l-l, Fig. 1.

Withreference now to the drawing, l' is a casing preferably of cast metal and generally hollow, having at its open mouth end, a flange la by which it may be mounted on a furnace wall, and a ceramic lining-all as is generally usual in the art; The casing has a lateral opening for air inlet connection lb and opposite this opening an endless bailie lc. 'Therear end of the casing is provided with a removable closure 2, mounted by bolts 2a or in any other convenient manner. It will be apparent that the described arrangement is such that the baflle lc forms part of a central passage leading toward the mouth of the casing, and also causes air in coming from the inlet lb to flow about the batie and toward the I closure and thence to the passage. The baiile is preferably provided at its rear extremity with a lip Id to direct the air toward the periphery of the closure 2, and the casing may have 'a corresponding lip le for the same purpose. The parts may be of circular section as indicated in the drawing, so that the passage within the baflie and leading out through the mouth end of the casing is cylindrical.

The closure 2 has a central portion extending rearwardly to carry a part 3 having a rearward gas inlet connection, and a pipe 4 is set into this part for delivering such fuel through the closure and to the passage within the baiiie lc. The rearwardly extending part of the casing is hollowed to clear the pipe 4 and to provide an enlarged chamber 2b thereabout. The part 3 has a chamber 3a about the pipe, communicating with the chamber 2b through an annular series of openings 2c in the end of the closure 2, this end having a. central opening to receive and preferably slightly clear the pipe 4 The part 3 is also provided with a lateral connection for a pilot fuel mixer 5, this mixer having suitable connections as indicated for pilot air and pilot gas. The closure 2 is provided with a lateral opening 26 to its chamber 2b, and an annular battle 2! extends turned into its illustrated internal flange, to extend within the casing l, is separating wall means arranged to provide progressive mingling of incoming air with incoming fuel. Such wall means comprises a series of endless wall members shown "as cylindrical and including an outer member 6,

a member 6a therewithin, and an inner member 6b. These wall members are of progressive length as shown in Fig. 1, the innermost being the shortest, and those within the outermost having adjacent ends spaced from the closure 2. The wall members are interconnected by webs indicated in Figs. 1 and 2, whereby their concentricity is maintained, and they obviously provide a series 01 annular air passages therebetween.

The outermost wall member S has a peripherally spaced series of lateral ports 60, and themedjacent an outwardly turned flange 8d. Mounted on this wall member between the closure 2 and the flange id is a sleeve valve I ported to correspond with'the ports 60 and adjustable about the wall member 6 for control of the latter.

. justment of this valve from outside the burner,

the closure 2 is arcuately slotted as at in to receive a bolt la turned into a flange on the valve I.

A nipple 8 having a rearward end bearing against the closure 2 and clearing the pipe 4, and a mouth end extending within the innermost wall member 6b, provides a sub-chamber! rearward of the wall members and having air inlet by the ports 8c of the outermost wall member. The rear end of the nipple 8 is castellated or otherwise deformed to permit flow of air radially inwardly adjacent the mouth end of the pipe 4 and the nippleis provided'with three external ribs la seating within the rear end of the innermost wall member 6b so that the nipple is effectively positioneda'nd centered between the sep- .arating wall assembly and the closure 2.

7 Operation will be as follows. The pilotair and gas being turned on by suitable valves not shown,

a pilot mixture is delivered to the chamber 3a,

, and flows in jets through the openings 20 and the base of the nipple.

The main gas and air supplies are then turned on. The gas flows straight through the burner, becoming ignited by the surrounding pilot flame as it leaves the mouth of the pipe, where it burns as much as is permitted by the slight amount of air entering the rear end of the nipple from the sub-chamber 9.

More particularly, the annular pilot flame emerging from the mouth of the chamber 2b, is disposed as a layer between the cylindrical core U of gas emerging from the pipe I and the substantially annular stream of air introduced at.

the base of the nipple 8 from the sub-chamber 9. Thus the pilot flame is thinned out and extended along the nipple, yet fed by fuel from within and air from without, and gradually and leaves the nipple, it mingles with an additional without interruption merges into and substantially becomes the main burner flame, so that the burner operates with great stability.

As the gas core, together with its outer layer of flame and products of partial combustion,

surrounding layer of air admitted through the annular space between the nipple and the innermost wall member 6b. Further progression through the burner admits further air successively from about the wall member 6b, from about the wall member 6a and ultimately from about the outermost wall member 6.

The gas is'introduced through the pipe 4 at 7 low velocity and the valve 1 is so adjusted-that air at low velocity mingles with the gas before air at higher velocity. In each stage of combustion the outer surface of the main gas column For ad-- is heated sufllciently to ignite the incomplete mixture of gas and air, and the heat generated by such partial combustion decomposes part of the hydrocarbon constituents into carbon and hydrogen. These partly burned gases are ultimately brought into contact with the mainair flowing at slightly higher speed through the burner about the wall member 6, andpventually complete their combustion beyond the mouth of' the burner.

The large passages within the burner for both air and gas allow low velocities and prevent rapid mixing so that the secondary combustion may take place over a relatively large area with sub stantially even heat distribution over the whole lengthof flame travel from the burner.

It will be observed that the parts which are subjected-to the most intense heat in service, may be easily replaced. Upon removal of the closure 2 the wall means 8 may be demounted from it, which releases the nipple I and permits removal of the pipe I.

What we claim is:

1. In a burner of theclass described, means providing a stream of gas, means providing a .supply of air for combustion of said gas, progressively about said stream, in increments having flow inthe direction of said stream and of progressively increasing velocities, and means providing a pilot flame immediately about saidstream adjacent the first of said increments to there initiate said combustion.

2. In a burner of the class described, a casing having a closure at one end and a gas supply pipe mounted insaid closure, said closure being arranged to provide a chamber about said pipe,

with a passage aboutsaid pipe leadingto the hollow of said casing, means providing a pilot mixture in said chamber whereby a pilot flame may be maintained at the mouth of said passage, said pipe having its mouth located adjacent said passage mouth. l 1

3. In a burner of the class described, a casing having an, open mouth end arranged for mounting on a furnace wall, a removable closure for its opposite end, a lateral air inlet, and a concentric transversely endless baifle arranged to form a central passage leading toward said mouth and tocause incoming air to flow first about said baille'and toward said closure and thence to said passage toward saidmouth, the furnace end of said baille being joined with said casing, means for delivering fuel centrally through said closure to said passage, and mu means mounted upon said closure and extending within said passage, concentrically thereof, for

of said air with said said closure and another wall member being mounted upon said first named wall member.

5. In a burner of the class described, a casing having a mouth end arranged for disposition at a furnace wall, a removable closure at its opposite end, and means providing an air supply within said casing adjacent said closure, means aromas for delivering fuel centrally through said closure into said casing, and wall means mounted upon said closure and arranged to provide progressive mingling of said air with said fuel and comprising a concentric series of wall members of progressively greater extent in the direction of fuel flow.

6. In a burner of the class described, a casing having an open mouth end arranged for mounting on a furnace wall, a removable closure for its opposite end, a lateral air inlet, and a concentric transversely endless baflie arranged to form a central passage leading toward said mouth and to cause incoming air to flow first about said baifle and toward said closure and thence to said passage toward said mouth, the furnace end of said bailie being joined with said casing, means for delivering fuel centrally through said closure to said passage, wall means mounted upon said closure and arranged to provide progressive mingling of said air'with said fuel, and comprising a plurality of wall members arranged within said bailie to provide an annular subchamber bounded endwise by said closure and some oi said wall members and peripherally bounded by a larger wall member, said larger wall member having port means located adjacent said closure to communicate with said subchamber.

'7. In a burner of the class described, a casing having a mouth end arranged for disposition at a furnace wall, a removable closure at its opposite end, and means providing air supply within said casing adjacent said closure, means for delivering fuel centrally through said closure into said casing, a transversely endless wall member carried by said closure, and a nipple mounted by hearing relation between saidclosure and said wall member.

8. In a burner oi the class described, a casing having a mouth end arranged for disposition at a furnace wall, a removable closure at its opposite end, and means providing air supply within said casing adjacent said closure, means for delivering fuel centrally through said closure into said casing, a transversely endless wall member carried by said closure, and a nipple positioned in abutting relation with said closure and having external ribs seating within said wall member end to permit inlet of air thereto.

9. In a burner of the ciass described, a casing having a mouth end arranged for disposition at a furnace wall, a closure at its opposite end, pipe means for delivering fuel through said closure into said casing, and means providing an air supply within said casing adjacent said closure and about said pipe means, means within said casing for delaying mingling of said air with said fuel, and pilot burner means carried by said closure and providing combustion immediately about said pipe means.

10. In a burner of the class described, a casing having a mouth end arranged for disposition at a furnace wall, a closure at its opposite end, pipe means for delivering fuel through said closure into said casing, and means providing an air supply within said casing adjacent said closure and about said pipe means, means within said casing for delaying mingling of said air with said fuel, and pilot burner means carried by said closure and providing combustion immediately about said pipe means, said pilot burner means including a wall providing an annular enclosure about said pipe means outside said casing and having an ignition opening to said enclosure.

11. In a burner of the class described, a central fuel inlet pipe having its internal walls substantially straight and parallel and uninterrupted whereby to provide a smooth-flowing fuel stream, means providing a supply of air for combustion of said fuel in increments at points progressively located along said fuel stream and at the periphery of said stream, said means having walls adjacent the point where the air enters said stream parallel to said first named walls and uninterrupted whereby to provide smooth-flowing air streams outside said fuel stream and substantially parallel to it, and means providing a pilot flame immediately about said fuel stream adjacent the first of said increments to there initiate said combustion.

GEORGE F. NAAB. 0TH LUTHERER.

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