US2367143A - Gas burner - Google Patents

Description

'H. D. SCII-IRADER 2,367,143

GAS BURNER v Filer; Maya, 1941 s Sheets-Sheet 1 '0, 6 FgJ.

"Jan. 9, 1945'.-

D. SCHRADER GAS BURNER Filed'My s 1941 3 Sheets-Sheet 2 Jan. 9, 1945.

H. D. SCHRADER GAS BURNER Filed May 3 1941 3 Sheets-Sheet 3 an n Great Falls, Mont, assignor to flnlllvanvalv'e and Engineer-in Butte, Mont, a corporation of Montana Application mp3; 1941, Serial No. 391,783

r Comp n s (o1. 158-9il) This inventionrelatesto andparticularly-to u'p-shot radiant gas burners per use under boilers, furnaces and the like.

we- .Obiects or the invention are to provide as burners or novel designdn which. the radiant surface extends over a larger part of the burner assembly than a has possible heretofore, and

in which theiietsioi flame span the secondary air space and sweep alongthe surfaces of the radiants. Anl-oblect is.-:to provides radiant gas burner in which the radiants extend over the burner outletsand are so shaped as to deflect any falling debris from the radiant surfaces and the burner openings. A further object is to provide a gas burner of the radiant type in which the burner heads are fornied as units that may be assembled in various relations to meet different space requirementa. Another object is. to' i provide radiant gas burner. heads of novel design that prevent a flash-back into the primary mixing chamber, that permit discharge'of the air- 'gas streams at a desired angle to the horizontal planeoi' the burner casting, and that iurnish a low pressure or trickle time that may be used alone or as a stabilizer for a. larger volume, high pressure gas flame.

These and other objects and advantages oi th invention will be apparent from the following specification when takenwith the accompanying drawings in which:

Fig. 1 is a fragmentary vertical section through a boiler combustion chamber in which a gas burner embodying the invention is installed;

, Fig. 2 is a schematic horizontal section taken onthe plane 01. line 1-4 oi Fig. 1, the burnerbeing shown in elevation;

Fig. 3 is a iragmenta'ry elevation, on an enlarged scale and partly in vertical section, oftwo burner units; a

Fig. 4 is a plan. view, partlyin section and onv the game enlarged scale, of the burner units of Fig.

1'13. 6 is a side elevation, with parts in section, oi two double burner units arranged at 'right angles'to each other, the section at, the right side -lating apparatus 8 in any desired manner. A

[of the Venturi tubes 3, see Fig. 2.

a combustion chamber and another multiple head burner construction embodying the invention;and

Fig, 10' i'sa. plan view of a burner assembly comprising arcuate burner heads of different size.

I The furnace structure illustrated in Figs. 1 and, '2 is typical of the combustion chambers in which,

the new'gas burner may be installed, but the furnace structure forms no part of the present invention.

3 In Fig. 1, the reference numeral I identifies one of the gas supply pipes or manifolds that are providedwith gas orifices 2 upon which the primary mixing chambers or Venturi tubes 3 are mounted. The upper ends of the Venturi tubes are of rectangular shape, as shown in Fig. 2, and have integral lugs 4 that space the tubes from each other to provide passages for secondary combusv tion air. Prismatic bodies 5 of insulating refractory material are supported on each Venturi tube and, as will be explained later, jets of flame are projected upwardly from the top of each Venturi tube 3, along paths indicated by the broken lines a, .to spanthe secondary air passages and to sweep along the surface of the radiant 5 of an adjacent tube. 1 a

.The complete burner assembly of Figs. 1 and 2 is of rectangular form to fit within a combustion chamber of that shape, and comprises two sets of four burner heads operating from two gas pipes 1. These pipes are connected to the main a gas supply line 8 through a diaphragm operated valve 5 that is controlled by a thermostatic regusmall pipe 9 is connected to the supply line 6 above the diaphragm valve to furnish gas to pilot'flame chambers III that are located at corners of certain A large volume of gas flows through the gas pipes l and enters the mixing chambers 3 at high pressure when the valve is f'ullyopen; and a small volume, low pressure supply of gas is delivered to the burner heads through the pipe ii that extends from the supply pipe 6 to the small Flss. '1 and 8 areslde elevations, partly in secair-gas mixing chamber l2 at the'inlet end of the low pressure air-gas pipe 13. The" outlets for the high pressure and the low pressure air-gas mixtures will be described later.

Combustion air enters the furnace chamber through inlet passages II and 15 th t have dampers 18 and I1, respectively, contr lled by the regulating device 8. The air streams from Each burner head includes a sleeve or distribution member 19 that is fitted within the upper end of. the Venturi tube 3, see Figs. 3'and 4.

The upper part of the member l9 flares outwardly and the inner surfaces of the flaring walls are notched or corrugated, by the integral ribs 20, to form a series of upwardly inclined flame jet outlets when the cap member 2| is seated within the member is. A prismatic radiant a is mounted on the cap member 2|, and

the sloping surfaces of theradiants lie substantially in the inclined plane of the flame Jets of adjacent burnei' heads. The -ribs 20- ofsdiacent distribution members -are staggered and the resulting series of non-intersecting flame jets follow the paths indicated by the broken lines a of Figs. '3 and 4, i. e.'the flame jets cross the path of thesecondary air and then sweep along the surfaces of the radiants.

The upper end of the Venturi tube 3 is set back from theouter flaring surface of the distribution element I! to provide a low pressure chamber 22 that extends around the top portion'of the tube 3, except at the previously described pilot flame chambers I0, and receives a low pressure air-gas mixture from'the pipe.

Notches 23 in the lower outer edge of the memher Is provide outlet openings, just belowthe level of the high pressure openings, for the low pressure chamber 22 and for the pilot flame chamber l0. Small. ports 24 may extend through the member l9 to by-pass a limited quantity of themain air-gas mixture to the low pressure chamber 22 -to supplement, or to replace, the supply through the inlet pipe l3.

The configuration of the prismatic radiant bodies 5a. of Figs. 3 and 4 differssomewl'iatfrom the radiants 5 of Figs. -1 and 2-, but the burner heads of Figs. 1 to 4 havethe same general operating characteristics. A maximum heat de'- mand results in ,a full opening of the diaphragm valve I and a'supply of high pressure gas to the pipes I. Any tendency towards a blow-out oi thgwhigh velocityniiames from the interspaces be een ribs 20 of the member I! is offset by the stabilizing action of the low pressure flames projected from the chamber 22 through the notches 23. A low. heat demand 'thatresults in a, closing of the diaphragm valve 1 does not interrupt the supply of gas to the low chamber 22 through the pipe .I I.

P am

As illustrated in Fig. 5, each Venturl tube may be bifurcated at its upper end to ture aroundthe periphery of the burner head and to preclude a flash -backinto the primary mixing chamber. A conventional pilot burner lead to the pilot flame chamber m in. one. unit in may be parallel to each other or, as illustrat= ed, adjacent burner units may be displacedan gularly by 90.

As shown in Fig. 7, the Venturi tubes 30 may have cross ribs 3" to which trough==shaped members I90 are secured by screws IS, the members Ilc having lower ribs 200 that space the members I80 from the tubes 30 to provide the out= let openings for the combustion gas Jets. Radiants 5c are seated in the trough-shaped members lie, and diflusion screens or bafies 280 are clamped to the ribs 3 by the members I90.

The embodiment of the invention that is shown in Fig. 8 comprises a Venturi tube $11 that terminates at its upper edge in ribs 3! that support the distribution member I911 upon which the radiant Id is seated. The lower sleeve of member 19d has a. plurality of small openings 32 that connect the mixing chamber of the tube M with the air-gas chamber'33 that is formed between the member Mid and the inner wall of the Venturi tube 3d. The small openings 32 equalize the flow of the air-gas mixture into the different parts of the chamber 33, and also prevent'a flash-back of the flame into the main mixing chamber in the event of a fluctuating gas pressure or other disturbing condition. g

In the embodiment shown in Fig. 9, the gas supply pipe I' extends into the Venturi inlet 8b of an air-gas manifold :4 upon which the burner head castings 35 are mounted by tapering joints. The burner heads may be of any of the described types and, as illustrated, include distribution members lie similar to those shown in Fig. 8. The ports 32' are inclined, however, to increase the protection against a flash-back. The radiants may be of the previously described geometry or, as illustrated, may be flat topped members 5c of either circular or rectangular crosssection. The radiants havebeveled edges to obtain the scrubbing" action of the flame jets along the surfaces of the radiants. The Venturi inlet 8| is located within a metal box 36 to which the supply of primary combustion air is con- 'trolledby adamper 21.. The air inlet box has another opening for admitting secondary air to the furnace chamber under control of the damper 38. Both dampers are adjusted automatically by a. modulating regulating device, not shown,

of any desired or known design. This independent control of the primary and the secondary air.

increases the emciency of operation and prevents a flash-bitch into the mixing chambers when the main gas valve to the burner assembly is opened. Aseparate pilot flame unit may be provided or, as shown,- asupply line 8 may of the burner .gssembly.

- heads with radiants U. 5g of different diameters The, p'""" ,v iously described embodiments of theinvention include burner head units of rectangular form but, asshown in Fig. 10, arcuate burner may be employed to fo a concentric arrangement of coaxial-burner head units.

It is to be understood that the described embodiments of the invention are typical of appropriate constructions, and thatf'cther varia tions 'in the design and relative arrangement of 2! may be positioned adja'cent'the burner heads to replace the internal pilot flame chambers of the previously described embodiments of the invention. when the outline of each double burner head is square, as viewed in plan, all radiants the units fall within the spirit of my invention as set forth infthe following claims.

I claim: g

1. In. a gas ;--burner comprising a vertically disposed Venturi tube member having gas and air inlets at its lowerfend, a distribution mem ber seated in the upper end of said Venturi tube g p "2,36 memberand an insulating refractory radiant member seated on said distribution member, oneof said distribution and refractory radiant members having spaced ribs to. provide flame jet butlets for the air-gas mixture from said Venturi tube member and said radiant member extendinglaterally at least as far as said distribution memher, the improvement consisting in that said radiant member 'has an upper surface which slopes outwardly and downwardly at an-angleof about 45 to the horizontalto thelateral'boundary thereof, the intersection of said suriace with ing a plurality of in'dividualiburner units so positioned and spaced from each other that flame jets of each burner unit are directed parallel and adjacent to a sloping. surface of. the radian member of an adjacent burner unit.

-3. In an up-shot gas burner, a Venturi tube enclosing a high pressure gaschamber, an air inlet and-a, gas inlet'at the lower end oi! the v. .ve muberorsu lm man pressure s s ixmeans within said'Venturi tube-and cooperating therewith to forma low pressure gas chamber surrounding said high pressure gas chamber, low pressure flamejet openings extending from said low pressure chamber between-said wall means and said Venturi tube, an'insulating refractory radiantclosing thejupper'er'id. of said high pressure chamber, and cooperating with saidwall means to define high pressure flamejetopenings,

and means for supplying low pressure gas to said. low pressure chamber, said radiant having an up? per su'rfacesloping downwardly-and outwardly I such that when out by a vertical plane extend ing 'in the direction of maximum slope the intersection. of the surface with the plane is a straight line. v g 4. An up-shot gas burner as defined in claim 3 in which openings in said wall means connectsaid high pressure chamber with said low pressurechainber. t. v

5. A burner as defined in claim 1; which the distributionmember is made of cast iron and is continuous across the upper end of the Venturi tube member.

I ,HARonn-n.

,ture tosaid high'press ure gas chamber, wall

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