US2930599A - Apparatus for heating metal work - Google Patents

Description

March 29, 1960 T. w. MuNFoRD ETAI- 2,930,599

APPARATUS FOR HEATING METAL WORK Original Filed Jan. 14. 1952 2 Sheets-Sheet 1 2 f A //////.//J/////H// r 2 .h

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March 29, 1960 T. w. MUNI-'ORD ETAL 2,930,599

APPARATUS FOR HEATING METAL woRK original Filed Jan. 14, 1952 2 Sheets-sheet 2 al 251 6/ 2?) fPgg E l i /44 45 /56 44 l l I j ("1 I @jf-h 55- i 40 Nimm' @www T Tm-AL- INVENTORS T.' WMUNFDRU de By D NESB UIT f APPARATUS FR iEATNG METAL WORK Theodore W. Manier-d, Toledo, and John D. Nesbitt, Sylvania, hio, assignors, byV mesne assignments, t Midland-Ross Corporation, Cleveiand, Ohio, a corporation of Ohio Continuation of application Seriai No. 266,256, January 14, 1952. This application January 20, 1953, Serial No. 711,541

2 Claims. (Cl. 263-2) This invention relates to heating of work by fuel cornbustion apparatus suchA asgas fired furnaces, and is designed to provide more rapid heating of work by impact firing than heretofore known for thel same number of burners or burner capacity. A. new method of heating, utilizing a broken or highly porous refractory bed, provides with only over-red burners heating rates as good as or better than before known for opposed burners used to heat work therebetween.

For a consideration of what we believe to be novel and our invention, attention is directed to the following portion of this specification and the drawing and concluding claims forming a part thereof.

in the drawing:

Fig. 1 is a partially sectioned elevation view of apparatus according to this invention.

Fig. 2 is a cross-sectional view of the apparatus of Fig. 1 on line 2 2 thereof.

Fig. 3 is a plan view of a portion of the hearth of the apparatus of Fig. 1 on line 3-3 thereof.

Fig. 4 is a plan View of the apparatus of Fig. 1.

Fig. 5 is a cross-sectional view of an alternate burner to that shown in Fig. l.

The apparatus comprises a hearth formed by refractory and insulating linings 21 and 22, respectively, supported by metal walls 23, a series of burners 24 supported thereabove by a framework 25 of water pipes, and a flue section composed of a metal shell 26 lined by refractory 27. The framework 25 of pipes, is in the form of an A frame, the closed loop portion being supported as a cantilever from the ends 30 and 31 of the frame which serve as inlet and outlet ends of the pipes for water owing therethrough. Water enters the inlet end 30 of the A frame and passes to the outlet end 31 by at least one of several possible flow paths: through the top portion 32 of the A frame, which serves as a support for the burners 24 and is desirably kept cool by iiow therethrough, and returning through a metering orifice in plate 33 in the leg of the frame leading to the outlet end 31 thereof, and thence to said outlet end, or through a by-pass pipe 34 and a valve 35 therein for increasing the minimum ow through the top portion 32; through an orifice in a plate 37 in the cross-bar portion 36 of the A frame which serves as a second support for the burners 24 and is kept cool for the same reasons as is the first mentioned support through said cross bar portion and to the outlet end 31, or through a bypass pipe 40 and its valve 41 around the plate 37 to increase the minimum flow through the cross-bar 36; or from the inlet end 30 of the A frame 25 to the top 32 of the A frame which serves both as a physical support for burners 24 and as a water supply manifold for the water-cooled walls thereof, through burner water inlets 42, passages 43 in the burner walls, burner water outlets 44, into crossbar 36 of the A frame and to the outlet end 31 thereof. The burners are supported on the frame 25 by supports 45 and 46 at either end thereof, though the pipes forming the water inlets and outlets 42 and 43 may be made suiiicient for the pur- 2,930,593 Patented Mar. 2Q, i960 pose. lFullyA aerated fuel gas is supplied-:through fuel manifold 47 and fuel pipes 48 to a fuel chamberwithin the burner walls, from whichv it is discharged through ports 51 along the rectangular combustion vtunnel formed by refractory sidewalls 52 ofthe burne r. Thev burners 24 are closely aligned on the frame 25 and areV spaced.

hearth therebelow for heating. Any, suitable, conveyor.

may be used, such as a chain typer or parallel screws.

It is preferred to roll the work asitI moves acrossthe hearth, as is generally inherent in a screwftypeconveyor when the work is round in section. Theseveral pieces Ware spaced froineach other.-to allow gasesofcornr-l bustion to pass therebetween, and the work is heatedon adjacent sides by radiation from the burners and hearth. Thus when several burners are used for such impact lame heating of the-bed, or hearth, as herein described, the work is quite uniformly heated without such turning.V

The gases of combustion are of course burning within the combustion tunnels of the burners 24, and as they pass through the work to the broken refractory bed therebelow they deliver some heat to the work by convection. The hot gases enter the porous refractory bed and heat the refractory pieces thereof to incandescence. There is a completion of the combustion reaction taking place within the refractory bed, and there is certainly a far more effective heating of the hearth than when the hearth presents a solid surface to the gases from the burners. lnstead of a solid hearth having a series of hot spots veach under a combustion tunnel, where not shadowed by a piece of work, the broken refractory heats thoroughly and uniformly, even if not placed precisely under the com-bustion tunnel, and the resulting uniformly hot hearth pre sents a greatly enlarged radiantly hot surface from which to radiate heat to work thereabove. It has been found in actual practice that heating rates possible with the type of furnace, or combustion apparatus disclosed are at least equal to those with double the burner capacity, the burners being disposed in opposed relation with work con veyed therebetween.

The flue disposed next adjacent the hearth at the opposite side thereof from the work conveyor 54 serves to draw ue gases from the work without passing `from end to end of the hearth along the work, the relatively short but hot refractory stack being adequate for the purpose. The burning gases thus pass through the broken refractory bed of the hearth to a point remote from the impacting stream from the burners above, and gases from one Iburner do not interfere with combustion of gases from an adjacent burner. The flue section, by drawing iiue gases from the hearth, permits a relatively sharp line of demarkation between the portion of the work heated and the portion outside the hearth area, simplifies maintenance of the conveyor for the work, and reduces the temperature to which the piping and steel work around the burner is subjected.

It is apparent that this invention is especially well adapted to heat elongate work of the class of rods, bars and tubes, when pieces of such work are supported from without the heating zone formed between the burners and the broken refractory hearth. When the lwork is substantially continuously conveyed through the heating zone formed by several burners, very accurate control of the degree of heating of the work is afforded by control of the effective speed of the conveyor. This application is a continuation of application S.N. 266,256 led January 14, 1952, `now abandoned.

We claim:

1. Apparatus for heating metal work which comprises a hearth formed'by a bed of discrete particles of refractory which is porous to a stream of gases, a burner comprising a refractory tunnel for discharging a stream of ignited and burning gases, the burner being arranged to discharge said gases against the bed whereby to penetrate and heat the same and to form between and spaced from the burner and the hearth a heating zone for heating said work, conveyor means disposed on one side of the bed for conveying rods, bars or tubes through the heating zone, in-

ternally cooled support means for supporting the burnerabove the hearth, the burner comprising internally cooled walls, and connecting means for connecting the support means to the yburner in a manner to allow flow of coolant from said support means through said burner walls and back to said support means.

2. Apparatus for heating elongate work which comprises: a hearth formed by a porous'bed of discrete particles of refractory bounded on the bottom side by a nonporous wall; burner means disposed directly above the hearth for discharging into said bed a stream of ignited and burning gases; wail means forming a continuation of said bottom side of said non-porous Wall and also forming a flue adjacent said bed, said ue being in communication with said bed below the hearth surface thereof whereby gases may pass through said bed to said iiue; and conveyor means disposed beside said hearth for conveying elongate pieces between said hearth and said burner means, said flue being opposite said conveyor means and adapted to draw ue gases from above and below the hearth level to promote combustion within the bed and avoid string out toward said conveyor means.

References Cited in the tile of this patent UNITED STATES PATENTS 434,092 Schinneller Aug. 12, 1890 839,064 Greenawalt Dec. 18, 1906 1,393,654 Wales Oct. 11, 1921 1,469,178 Ellis Sept. 25, 1923 2,511,676 Morton lune 13, 1950 UNITED STATES PATENT oEEICE CEBTEFICATE 0F @ERECTION Patent No, 2330599 March 29 1960 Theodore W1, Mumford et 31 It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column .ll line 13I for "string" read sting mm lSigned andsealed this 27th day of September 1960.

( SEAL) Attest:

KARL Hg AXLINE Attesting Officer ROBERT WATSON Commissioner of Patents

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