US2151973A - Burner unit - Google Patents

Description

March 28, 1939.

R. JOHNSON BURNER UNT 'I' Filed Mal'` 18. 1956 m d n .O 5 .n .In O Wd w QIJH MNO. 2 9:2 L. .A ,In B w B L .1/ F f l/O 2 l onthelineI-i'" of 'In Patented Mar. 2s, 193e UN1T1-:D six-friasl PATENT OFFICE My inventionl relates to `the burner unit of an l overfeed type of coal stoker, and would ordi-v narily be associated withV automatic feeding means to constitute an automatic stoker.

5 fuel employed will usually be coal, although my invention is not to be limited' to the use of coal alone, as other materials may be'burned in this unit or mingled with the coal'.

Burners have generally been made of cast iron Y or like metal, fgr the reason that lthe cast ironA resists`- distortiony and burning out' when sub# jected to the heat of. the ilre, and does not tend to cause the formation of clinkers. Cast iron construction, however, is relatively expensive inv the shape necessary for such burners. It is one of the principal objects" of this invention to provide a burner structure which primarily by the use of structural steel shapes and steel plate can be welded together, and can be assembled cheap# ly,'yet effectively, and which is provided, if need be, with cast iron elements which can be very cheaply made, to be used at points where the :tire would tend to burn out or cause clinkers if of steel construction, so that. the wholeburner may be produced less expensively and at least as quickly and conveniently as a cast burner unit.- Itis a further object to incorporate in such a 'A burner unit, as the principal element thereof and the one which 'gives lt its principal strength;

- a piece of structural steel shape. such as "an 40 I n the accompanying `have shown my inventiony in an illustrative f orm asnowpreferredhymen"l Figure 1 is a plan view 45 FigureZisalOnglhldialsectlonthrough me, line 2121-22-19! 55. air' chamber beneath itpreferably by a pan 'or The" c It ls desirablethat the fue] be permitted t0 l the" 5 'The has ofthernay wel-I bea box 2, formed to extend beneath the web I0 an `Welded thereto as indicated at n. If desired, the

upper flanges and web of an I-beam shape might constitute the flanges I l and web In, respectively, and the downwardly ,projecting flanges would 5 form a support for the fuel chamber I 5 and sides for the air chamber 2|. 'I'he box 2 itself may be ofcorner welded construction, cut from sheet steel, or, where an I-beam shape is used, the sheet steel would form the bot-tom and ends of the l0 box. This, in conjunction with the web I0, constitutes an air chamber 2|. The hearth is provided with slits 30 constituting grate apertures. Since it is desirable to employ a cast iron grate, coal tending to clinker and l5 Y stick to a steel grate, it is preferred that Aa. large 'sperme 12 nush with the upper surface of the 20 we b Il. To this end cleats I3 may be welded to the underside of the web at two opposite edges of the aperture l2. By removing the grate 3 the air chamber 2| may becleaned out when necesspread somewhat by the time it reaches the flre. Itis delivered from a fuel supply pipe 5 by any suitable means which advances it therealong to deliver it upon the upper surface of the web lll; 30 for example a worm 5l may be employed. The pipe. 5,.then, is connected to the Vend of the burner opposite the grate I, and to form a fuel'chamber I5 for the spread of the fuel and to conne gases distilled from Vthe coal and to force them through the burning massi Ipneferably provide a hood Il of inverted U-shape form in cross s ection, which may be made from a structural channel shape, resting upon and welded at I9 to the upper edges of the flanges Il, and extending in- 40 ward to a point adjacent the grate 3. 'Ihe fuel chamber Il is completed by anend p late I 6 which is-welded across the end of the-channel I and of the hood Il, suitably apertured for the reception ofthe fuel pipe .l and' an airisupply pipe i. '45

' Since-the stoker is of thel overfeed type,the opposite end ofthe fuel chamber Il is left open for discharge of ashes therefrom over the edge. of the web II.

Air for combustlonis supplied preferably under 50 pressure through the air supply pipe 6, which connects with the air chamber 2|. This pipe, which for simplicity and cheapness 'should be round, is shown asof somewhat larger diameter l than the height of the air chamber 2|, and simi- 55 larly the fuel supply pipe is somewhat greater in diameter than the height of the fuel chamber Il. In order to accommodate these pipes, which are welded in place in the end plate I6 of the 5 burner unit, or in the end of the pan 2, the web l Il is swaged, as indicated at I'I, to accommodate the fuel pipe, vrand at I8 to accommodate the air Dipe- 'Ihe coal piles up, over the grate 3. to a level 10 somewhat axacent the upper surface of the hood I I. It must be prevented from spilling over the edges of the flanges and upon the hood, and itV is undesirable that the steel parts be subjected to the direct heat of the nre. I therefore preferably provide an apron I which surrounds or encircles the re on at least three sides. As the gases, distilled by the heat of the fire 'from the fresh fuel behind the grate 3 and beneath the hood Il, emerge above the-flanges Il and over the front edge of the hood I4, they are constrained by-the apron 'l from escaping unburned in directions laterally outward from the top edges of the fuel and combustion chambers, but instead are directed up through the burning top layer of fuel and the heated zone thereabove.

Such gases are there burned, increasing the efiiciency of combustion, instead of being wasted. Furthermore, the iire is rendered more effective by being directed, by the apron I, upward as a concentrated column of intensely hot flame instead of spreading outward over a greater area. This upstanding. apron is of cast metal, and rests upon the upper edges of the flanges II inwardly of the end of the hood Il, and upon the inner end 0f the hood itself. 'Ihis piece may be 5 inserted through-the ash door ofa furnace, for

example, and the apron 'I may be put in place after proper installation oi.' thel main burner unit. In manufacture the shape I may be cut into sultable lengths with facility, and the remaining parts are of simple construction and the welding of' these parts together is very easily and cheaply accomplished. As a result not only is the burner strong and sturdy and long lasting, but it Vis inexpensive and readily installed.

55 What I claim as my invention is:

1. A burner unit for automatic stokers comprising a length of steel channel disposed horimentally, and having a web forming a hearth, and upstanding flanges, and apertured' in' its w web adjacent one end, a cast grate removably received in said aperture, a box welded beneath the web, constituting an air chamber communieating with the grate aperture, an air supply pipe discharging into said air chamber, a hood 5 covering the top of the channel end remote from the grate aperture end, and welded to the longitudinal flange edges, a fuel supply pipe delivering fuel upon the hearth beneath the hood for advance towards the grate, and a cast apron extending upward from the edges of the channel flanges, outside of the hood, and from the edge of the hood adjacent thereto.

2. A burner unit for automatic stokers comprising a length of steel channel disposed horizontally and having a web forming a hearth, and upstanding flanges, a hood covering the top of one end of said channel and welded to the longitudinal iiange edges, to define a fuel chamber, the web of the uncovered channel'end having grate apertures therethrough, a fuel supply pipe to deliver fuel to the covered end of the fuel chamber, a box underlying and welded to the channel and constituting an air4 chamberv communicating with the grate apertures, an air supply pipe to deli'ver air to the air chamber, and a. cast apron of U-shape extending upward from the uncovered edges of the two flanges and the adjacent edge of the hood, to retain the live coals, to confine the gases distilled from the unbumed coal, and to direct the flame upward in a column. y

V3. The combination of claim 2, wherein the fuel supply pipe is of greater diameter than the height of the hood above the channel's web, and the air supply pipe is of greater diameter than the air chamber, the web being downwardly and upwardly swaged, respectively, to receive said DIPGS. t

4.' A burner unit for automatic stokers of the overfeed type,jco`mprising a hearth having an l unobstructed edge constituting a discharge end for passage of ashes thereover, its opposite end constituting a fuel feed end, side walls integral with said hearth and upstanding from opposite sides thereof, a hood covering a portion of said hearth and the adjacent portions of the side walls at the feed. end thereof, a grate in said hearth, outside of the hood, a fuel supply conduit to deliver fuel to the feed end of 'said hearth and beneath said hood, and a U-shaped apron of a size to seat upon the uncovered portions of said' side walls and that edge of said hood which is remote from the supply conduit, and extending upwardly well above said hood and side walls.

' 5. A burner unit for automatic stokers of the overfeed type, comprising a. hearth having an unobstructed edge constituting a discharge end for passage of ashes thereover, its opposite end constituting a feed end, a grate in said hearth, an air supply conduit communicating with the space beneath said grate, sidewalls upstanding from opposite sides of said hearth, a hood covering the feed end of said hearth and the adjacent and that edge of said hood which is remote from,

the Vfuel supply conduit, and extending upwardly well above said hood and side walls.

' ROY JOHNSON.

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