US1768583A - Furnace - Google Patents

Description

July 1, 1930. F. J. DROEGE v FURNACE FiledOct. 31, 1928 2 Sheets-Sheet 2 Ida/gator By .Atmmey;

Patented July 1, 1930 UNITE1DYST"T S Faun mo g, or"? covm'eron, KENTUCKY 1 FURNACE I Application filed October 31, 1928.; seriar Nb. 316,259.

19 temperaturesattainable, as well as better Fig.3;

maintenance for correct operation. during the llf610f the furnace. Other objects will appear in the course of the following 'description.

' I attain these objects by: the device illustrated, for example;v inthe accompanyingdrawings, in whichf Figure l is a partial longitudinal vertical section on-theplane of the line l-l of v Fig.2 is a partial plan view, partly in horizontalsection on the plane of the line 2-2 of Fig.1; r

Fig. 8 is .a verticalicrossseotion on the 25 plane of the line 3-3 of Fig. 1;

Fig. 4 is a partial perspectiveview showing the water-containing. cooling elements in full lines, the outlines ofthe furnace and the water supply and discharge pipesbeing shownby.dottedlines; and p Fig. 5 is a partial ver'tical section corresponding to that of Fig. 1, showing a modification ofthe roofof the combustion chamber. v

' About one half ofthe' upper structure of an open-hearth regenerative furnace is illus-. trated; part of the hearth 1, "its-front wall 2' with doors3, its rearwall 2 I and its arched roof 4 and one of the, combustion chambers 5, being shown. As is; well knownin the art, the complete installation would include the continuation of the hearth structure,

and, at the opposite side'of this',.a second chamber 5 and regenerative apparatus unfor controlling the flow of airand gases so that each chamber-5 alternately becomes the inlet-while the other 'beoornesthe outlet to the regenerative apparatus, inwnich apparatus, on the way to the stack, these gases lment.

derall of these structures, including means heat the passages, which upon alternation heat the airthatis admitted with the fuel.

.These other partsfare omitted because the combustion chamber?) at the opposite side will be understood to be identical with the one indicated, and the regenerative device of any approved construction and arrange- At the outer side .of the combustion chamber 5 is the fuel inlet structurefi, comprising a vertical flue 7 that leads up froma source offuel supply, not shown, withthe horiis not afiected by my invention and may be n V zontal nozzle 8 leading in from the upper end of the flue 7 and opening into the chamber 5. This nozzle1 8 considerably wider than the flue 7 allowing the fuel tospread forwardly and backwardlyin itstravel'into the chamber 5 toward theair inlet structure 9 which are in the outer rearand'frontcor ners of the chamber 5, with vertical fines 10 7 leading up from the air passages of theregenerative' apparatus and opening upward into the chamber 5 above thelevel of the top of the fuel inlet nozzle 8. The roof 11 of the chamber- 5 slopes downwardly and inward-1y jfrom'the side walls of the furnace, and the front and rear walls 12 of they chamber 5 converge inwardly past the inner upper corner of the bridge 13 which forms the 1 bottom of the chamber, sloping inward from about the level of the bottom of the nozzle 8. Inward fromthis the baffle 14 V 7 extends up toa considerable height to join theroof 11; the bottom edge; of this bafile being above the level of the inner corner of the bridge 13. The hearth roof 4: inclines up from the lower edge oftheybatfle 14, v a

, hich edge is arched in conformity with the: arching-of this r'oof l. a

. Theresult'of. the above arrangement is i that the air streams from'the inlets 9 are deflected downwardly and toward the 'middle of the chamberjafter passing'upto the roof 11, thus meeting the fuel with a whirling or eddying motion'as the fuel comes up from and spreads to frontandrear from the nozzle 8, as roughly. indicated in- Figs. :1' and 2, where the light arrows indicate air streams and dark arrows indicate fuel streams. In addition to having the upright baffle 14 in place of the usual sloping roof next to the usual knuckle, the passage over the bridge 13 is preferably more con- ISO stricted than usual by carrying this baffle down lower than is the usual knuckle; this constriction adding to the effectiveness of mixture and combustion.

This bathing and constriction intensifies the heating and erosive effects of the burning mixture on the adjacent structures; and to make practical my improvements to aid combustion as above described, I provide for cooling these structures. The fuel inlet 6 has a water jacket'15 comprising n1emdefined between the lower and upper ledges,

while the tops of the upper ledges 18 and 21 are covered withsimilar material 24 and .the inside of the arch 22 is lined with similar material '25. The side wall 26 of the furnace forms the outer walls of the flue 7 and nozzle 8, as well as of the air I inlet flues 10; affording access to the lines Lil by knocking out portions of the wall 26.

The brickwork or equivalent refractory material'formin g the air inlet structures 9 is carried over the top of the water cooling arch 22 of the fuel inlet nozzle 8. The water jacket thus cools the fuel inlet 6 on three sides and its top, and, by its lateral portions 16 adjacent the air inlet flue walls, also cools these air inlets 9. Outwardly, these inlet structures are cooled by the atmosphere sufiiciently.

To protect the inner upper corner of the bridge 13, a pipe 27 runs through the furnace from front to rear, embedded in the structure of the bridge 13 up close to said corner. The baffle 14 is made up of a water jacket 28 with its top edge horizontal and its lower edge arched and forming the lower edge of the baffle as before described, and with its ends communicating with upright water chambers 29 set against the front and rear walls 2 and 2, respectively, of the furnace, and embedded in the inner edges of the converging walls 12 of the combustion chamber 5; these chambers 29 resting upon the foundation of the furnace and thus supporting the baflie' The jacket 28 has the hollow ledge 30 along its straight top edge, and hollow ribs 31, 32 and 33 from this ledge 30 down to the lower edge; these ribs diverging upwardly and, with the led e 30, being on the side of-the jacket 28' acing into the chamber 5. Facings 34 and 35 of brickwork-or the like are supported by these ribs and by the adjacent downwardly converging walls 12, and thus presented toward the mixing fuel and air within the chamber 5. The roof 4 is cooled by elongated front to rear water jackets 36 shaped to conform with the arching of the roof over the hearth, and let into the brickwork thereof at suitable intervals, allowing increased tempera ture at the hearth without rapid deterioration of the roof 4.

By providing eifective cooling means for the bafile 14 and the bridge 13, adjacent to the passage leading from the mixing chamher 5 to the hearth 1, the baffle 14 may be extended much lower than is the usual knuckle, without too rapid destruction of the bridge and baffle materials. Thus, the passage may be constricted as much as may be desirable for effective combustion, as an aid to the provisions for effective mixing before described. The eifective cooling of the upper portions of the bafiie 14, as well as of the fuel and air inlet structures, prolongs the life of the mixingor combustion chamber structures under the increased heat afforded by the above provisions. By proper cooling, the design of the furnace may be maintained, whereas heretofore, erosion and fusing of the structural materials has madethis difficult.

The various water jackets have watercir-' culated through them; an approximate arrangement of piping for this purpose being indicated in dotted lines in Fig. 4, where the main manifold pipe 37 has branches 38, 39., 40 and 41 leading, respectively, to the inlet jacket 15, bridge pipe 27 baffle jacket 28, and hearth roof jackets 36, and outlet pipes 42, 43, 44 and 45 lead, respectively, from these several cooling elements. Circulation through such a system may be maintained under gravity, or by suitable pumping apparatus, according to the amount of water required for cooling. This, of course, also will dictate the relative sizes of the jackets; and it will be understood that the cooling effect should not be such as to appreciably reduce the temperature of the furnace gases, but only such as to avoid too rapid deterioration of the furnace structure.

' In the modification shown in Fig. 5 the roof 11 ofthe mixing or combustion chamber 5' is in the form of an approximately semicircular arch from front to rear, affording a higher space into which the incoming air may rise, producing a more marked eddy of the air downward and forward in mixing with the fuel, aided by the baiile 14, which, with'the fuel and air inlets, as well as the other parts ofthe furnace, not shown, will be understood to be the same as in the example of Figs. 1 to 4, inclusive. 7 It will be understood that natural or producer gas is the usual fuel, but that other fuels, such as oil or other liquid fuels, with suitable spraying devices, may be used, with corresponding changes in the construction,

and that other modifications in proportions and arrangement, or' in application of cooling means, may occur- 1n difl'erent installations.

furnace, it is applicable to other metal treating apparatus, amon which may especially be mentioned soa ing pits of steel 7 plants. I do not .wish, therefore, to be understood as being limited to the precise dis- I closures herein, but having thus fully described an example of my invention and its mode of operation, as is required, what I claim as new and desire to secure by Letters Patent is: a V

1. In a furnace, a hearth, a combustion chamber having a passage to said hearth and having a fuel inlet and an-a'ir inlet, a baflle constricting said passage and forming an upright wall of said chamber, facing said inlets, a water. jacket comprised in said baffle, and water chambers at the ends of said bafiie next to the walls of the furnace, communicating with said water jacket.

2; In a furnace, a hearth, a combustion chamber 'having'a passage to said hearth and having a fuel inlet and an air inlet, a bafiie constricting said passage and 001m prising a water jacket having upwardly diverging ribs facing said inlets, and refractory material supported by said ribs.

3. In a furnace, a hearth, a combustion chamber comprising an outer side wall, a

, the respective corners of said outer side, wall and the front and rear walls, openingv front wall and a rear wall, air inlets near upwardly, a fuel inlet near said outer" side wall and between said air inlets, opening toward said hearth below the airinlet openings, said combustion chamber having a bottom extending from said air and fuel inlets toward said hearth and having a roof above the upward openings of'said airinlets, and having a bafile wall next to said hearth, extending down in said hearth close I to the hearth end of said bottom of said combustion chamber and extending upright to said roof, above the level of said air inlet openings, whereby air from said air inlets rises to said roof and is deflected thereby toward said baflie wall and is deflected downward by said bafiie wall to strike substantially vertically upon the fuel coming from said fuel inlet to mix with said fuel a in the space between said inlet and said baffle wall, over said bottom of said combustion chamber, before entering said hearth below said bafile'wall.

V FRED J. DROEGE.

Also, while the invention is illus-' trated as applied to an open hearth melting

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