US2675864A - Burner for open-hearth furnaces - Google Patents

Description

April 1954 J. J. SEAVER BURNER FOR OPEN'-'HEARTH FURNACES 2 Sheets-Sheet 1 Original Filed March 15, 1950 Ap 1954 J. J. SEAVER 2,675,864

BURNER FOR OPEN-HEARTH FURNACES Original Filed March 15, 1950 2 Sheets-Sheet 2 Patented Apr. 20, 1954 BURNER FOR OPEN-HEARTH FURNACES Jay J. Seaver, Evanston, Ill.

Original application March- 1950, Serial No. 149,720. Divided and this application February 28, 1952, Serial No. 273,849

6 Claims.v

The present invention relates to burners such as are utilized in firing furnace crucibles and is particularly concerned with open hearth furnace burners of the type used in multiples for directing combustion supporting gases in respect toa hearth bath.

This application is a division of copendingapplication Serial No. 149,720, filed March 15-, 1950, now Patent No. 2,640,692, dated June 2; 1953. I

A principal object of the invention is to produce a directional flame projecting-nozzle type of burner for open hearth furnaces which will issue a flat divergent flame, which may be posi tively secured" in aninfinite variety of aimed positions respecting a furnace crucible, and which may be expeditiously controlled to promptly retract its supply nozzle and generator apparatus from exposure'in the'burner tube housing during" recycle firing intervals while simultaneously plugging the burner tube apparatus to prevent infiltration thereof by gas borne solids.

Additional objects and features of the invention will be brought out in the course of the detailed description of certain embodiments; which will presently be rendered with reference t'o'i the accompanying drawings. In these drawings,

Fig. 1 is a diagrammatic sectional view through portions of an open-hearth furnace taken approximately along'lin'e l'-| in Fig. 2;

Fig. 2 illustrates in similar dlagrammatic representation corresponding portions of the furnace in sectional view taken approximately along. line 2-2 in Fig. 1; V

Fig. 3 shows an embodiment of the novel burner structure partly in diagrammatic elevational and partly in diagrammatic sectional view,

the sectional view being taken approximately along line 31--3 in Fig. 4; I Fig. 4 represents a diagrammatic end. view of theburner structure and control therefor, as

seen from the outside of'the furnace, that is,

seen from the left of Fig. 3; and

Fig. 5 is a diagrammatic end view of the burnerv structure as seen from the inside of the furnace. hearth, that is, as seen from the right 'of Fig. 3.

Like parts are indicated by like referencenumerals'throughout the. drawings. 7 and details will be discussed only to. the extent. required for explaining what is considered new.

The'open-hearthfurnace shown in Figs. :1 and 2 includes the usual principal sections comprisingthe furnace hearth structure proper, which is generally indicated by numeral ll';two conduit secftions one'at either end' of the hearth struc- Known elements entrained in the exhaust gases are precipitated intoand deposited onthe floor of the slag chamber l-3; the gases free' of solidspassing through the checker chamber M transmit' the heat to the bricks insuch chamber, the bricks retaining the heat for heat-conserving purposes. The current is' periodically reversed, after removing the-- solids deposited in the slag chamber [3-, andfres-h: air i-sinj'ected into theflue I 5-for passage through the heated bricks inthe checker chamber i4 where the air is pre-heated, 'passing'the'n through the slag chamber and upwardly through the conduit 12 to the furnace hearth to sweep over the hearth bat-htothe other end thereof for exhaust through the conduit at suchother end, which corresponds to the conduit [2, and further passagefrom this conduit to the corresponding slag chamber and thence through the associated checker chamber t'othe exhaust flue.

In the parlance of the art, the;- conduit i2- is referred to either as downtake or as fuptak'e, depending on the operation cycle during which the gases'sweep either downwardly from the" furnace hearth in the form of exhaust gases or upwardly as fresh pre-heated air to the furnace hearth to aid in the processing of the hearth bath;

As shown in" Figs. I and 2, the roof of the furnace hearth comprises a number" of trans extending arch 24 made of suitable refractory material. At each end of the-structure is disposed a roof portion-2'5 likewise made of refractory material joining with the Wall 30' at the top 3| thereof.

The hot gases created by burners such as 21 and coming from the uptake [2 at the right end of the furnace hearth, as seen in-Fig. 2, sweep over the hearth bath on the hearth floor 26 from right to left, asigene'r'ally indicated by .the arrows Fig. 21- 7 Y 7 The new burner structure diagrammatically M containing suitable bricks through which the exhaust gases pass for heat exchange purposes and finally for exhaust through the flue ['5 to a suitable stack. Solids- Disposed shown in Fig. 2 at 21, with its control means generally indicated at 15, will now be described more in detail with reference to Figs. 3-5.

Referring now to Figs. 3-5: Numeral 30 indicates the furnace wall shown in Fig. 2 by identical reference number. This wall is provided with openings 16, one for each burner. It has been assumed in the example shown in the drawings that there are three burners 21, i3, and 14, as shown diagrammatically in Fig. 1. More or fewer of such burners may of course be provided.

Each burner comprises a cross-sectionally generally oval or elliptic housing and cooling jacket having the walls H, E8 which converge at the inner operating end to form a relatively wide nozzlelike opening 19. The walls 11, 18 form the chamber 86 for the flow of cooling water which may be circulated through the structure by way of the inlet 3! and outlet 82. The housing or jacket has been assumed to be of oval or generally elliptic structure, but can of course assume any desired form; for example, it may be cross-sectionally circular or square.

Suitably secured to the outside of the housing at a point near the outer end thereof, that is, where the burner projects to the outside of the furnace through the opening It in the furnace wall 30, is a circular bearing ring 83 which rides in a cage B l, the latter being fixedly mounted on the furnace Wall 33 by means of a bracket 85 which in turn is carried on the plate 86. The cage 8 is provided with a suitable number of recesses 87, each containing pressure shims or shoes, as particularly shown in Figs. 3 and 4 for coaction with corresponding bolts, so as to fix the bearing ring 83 and therewith the corresponding burner in any position of angular adjustment with respect to the fixedly mounted cage. The bearing ring 83, riding in the cage 8 2, thus coacts with the cage in the nature of a universal joint, which permits adjustment of the corresponding burner angularly with respect to the hearth bath so as to focus the burner flame upon the hearth bath as desired.

Disposed within the cooling jacket or housing is the burner proper which comprises an outer tubular member 95] forming an annular space 9! with the inner tubular member 92 which is concentrically disposed therein, as particularly shown in Fig. 3. At the outer end is an inlet 9 for supplying to the inner tube 92 any suitable fuel, which may be oil, gas or tar, for example, and an. inlet 95 for supplying to the annular space SE a suitable atomizing fluid, which may be air or steam, for example. At the inner end of the tubular member 92 is provided a distributor element 95 consisting of a flat member which extends substantially across the inner clearance of the outer tube 90, and forms three nozzlelike openings 97 (see also Fig. which communicate with the inside of the fuel-feed tube 92. The distributor 96 is held within the outer tubular member so by means of a spider 98. The inner 'end of the outer tube 90 is fiattened as indicated at 99, to form a Venturi-like nozzle opening which is disposed within the elongated opening 59 formed in the irmer face of the housing or cooling jacket.

The flame which will issue from the nozzle opening of the above described structure will be a flat, wide flame instead of a circular flame, which is in keeping with the intended operation of the burner, to produce a concentrated flame that can affect a relatively large area of the hearth bath. The angle at which this flat, wide' flame strikes the hearth bath is adjustable, as previously described, and inasmuch as there are a plurality of such adjustable burners it is possible to produce a flat, wide flame of desired width and intensity, composed of the flames of the various burners, and properly angularly focused upon the hearth bath to obtain the best effect and the most efiicient operation.

It may be mentioned in passing that this angularly adjusted, flat, wide, flame, which may thus be produced by each burner and by all burners combined, also contributes toward favorable conditions which promote the efiicient utilization of the new roof structure discussed previously. It is clear that, if the flame is focused upon the hearth bath and concentrated thereon, like a fiery sheath which extends substantially in parallel to the transverse plane of the hearth bath, the flame and the heat are used where they are needed, keeping them away from direct contact with portions of the roof.

As indicated before, the furnace is operated in cycles, using first the burner or burners at one end of the hearth, for example, the burners disposed at the right end of the hearth as it is shown in Fig. 2. The gas stream, including preheated air, will then sweep over the hearth bath in the general direction indicated by the arrows in Fig. 2. After a while this particular burner or burners at the corresponding end of the hearth are shut off, the solids deposited in the corresponding slag chamber are removed, and fresh air is drawn through the checker chamber where it is preheated, to flow upwardly through the uptake shown in Fig. 2 to sweep over the hearth bath, and at the same time the burner or burners 2'5 shown in Fig. 2 are ignited to produce the angularly adjustedfiat and wide flame which is focused on the hearth bath, as described before. At this particular time, while the cycle is in operation, the burners at the opposite end of the hearth must be protected against the ingress of slag and solid particles which are propelled across the hearth with the gas stream flowing for exhaust toward the corresponding downtake, as already described.

The device for protecting an inactive burner against the ingress of solids entrained in the gas stream, which comes from the opposite end of the hearth, includes control means comprising a cam cage lilil which may be operated by the connecting rod Hll extending from the piston I02 which projects from a hydraulic or suitable compressed air cylinder H13. Any desired operating liquid or fluid may be circulated through the cylinder I03 by means of the inlet and outlet I04 and H35. Known control means such as valves and the like have been omitted to simplify the drawing. At the lower end the cage I99 carries a guide rod I66 which moves within a bearing bushing it? carried by an arm I88 of a bracket having a mounting hi9. On the housing or cooling jacket of the burner, that is, on the outer wall W at the outer end thereof, is mounted a ringlike member HE] which carries arms lH projecting upwardly and arms H2 which project downwardly. The arms i i l form a mounting H3 which carries a bracket H4 having an extension l 15 for supporting the cylinder Hi3, and the arms H2 carry a mounting H6 for securing the bracket member H39 from which extends the arm E68 carrying the bushing I 8'! for guiding the pin Hi5 secured to the lower end of the cam cage I00.

The cam cage Hill is provided with cam slots I and i2 1. Inthecam I23 carried by an outer tubular member 90 of the burner proper, and in the cam slots i 2 ride pins 124-, l2 5'carried on the operating member I having a reduced rod-likeportion which ex-- tends into a boringin theplug rod I-Z-l. The latter, at its inner-end, is of" iiat configuration with its ront end tapered as shown'in- Fig. 3, or carries a flat plug member for plugging the clon gated opening is in the inner end of the housing or cooling jacket Ti into which extends the Venturi-lilze inner end: 99 of the burner.

Now, when it is desired to plug the opening. 19 of. the housing or cooling jacket of a particular burner against ingress. of solid particles; that: is, when it is desired to make the particular burner inactive; preparatory to igniting the burner at the opposite end of the hearth, cperatingfluid is injected into the cylinder Hi3 to drive down the cam cage H33, and during such operation the cam slots H5 cause the pins !22, i2 3 to displace the burner element comprising the fuel supply tubes 99, 92 within its housing or cooling jacket by moving it through a composite motion including a slight angular displacement in a counterclockwise direction andat the same time withdrawing it axially rearward-1y, thus moving the flattened Venturi-like inner end 955 of the burner element to withinits housing. and disposing it in angular position in the upper portion thereof. At the same time the cam slots I21 operate against the pins iZ i, I25 of the actuating member i2 5, driving this member inwardly and causing the spring i321 to move the plug l2? inwardly, at the same time displacing it counter-clockwise until the inner tapered end of the plug I27 closes the opening i9. It is to be noted that the plug is actuated through the medium of the spring I36 to put its tapered inner end yieldingly in engagement with the inside walls of the jacket forming the opening E9. The ends of the spring [3% are suitably secured, one to the actuating member 25 and the other to the outer end of the plug 52'? so as to effect the withdrawal of the plug l2! again in a yielding manner by the spring we. This resilient or yielding operation of the plug protects against damage the inner end of the housing or cooling jacket forming the opening 19.

After the burner, or each of the burners, at the corresponding end of the hearth is put in inoperative position and its flame opening plugged, as described above, the next operating cycle can proceed after first putting the burner or burners at the respective end of the hearth in operative position. This done by again injecting operating fluid into the cylinder ice for moving the cage [00 in opposite direction, namely, upwardly, during which motion the burner element within its housing or cooling jacket is moved in a composite motion angularly clockwise and at the same time inwardly into the position shown in Fig. 3, while the associated. plug 121 is moved in a composite motion angularly in clockwise direction and at the same time outwardly until it is in the position shown in Fig. 3. The corresponding burner is new again in operative position.

Changes may be made within the scope and spirit of this invention as described in the foregoing. Accordingly, what is believed to be new and desired to be protected by Letters Patent is that set forth in the hereunto appended claims.

I claim: 7

1. In an open-hearth furnace, a burnercom prising a housing forming a cocling'jacketwhich forms a nozzleli-ke opening at the inner end thereof, means for adjustably mounting said housing ina wall of said furnace with the: inner ja'cl iet', means for" retractingflame-produc:---

element within said jacket, and means for: plugging said nozzle-like" opening of said jacket; 2 burner for an open-neartn fui na'c'e comprising: a double-walled casingforming a. space f'cr circulating a cooling liquid therethrough; a;v universal joint for angularly adjustabl y mount ing saidcasing on aw'all of said furnace, means for mormg sai-d casing for adjustment and for securing it in angularly adjusted position, a-

burner element within saidcasing having a tubular inner end for flame-throwing alignment with an opening formed at the inner end of said cas ing, mounting means carried by saidcasing at: the outer end thereof, canr means movably ried by said mounting means', actuating means for saidcam means, and; means operable by saidi cam means for adjusting the position of said': burner element; within said; casing; l.

3-. A burner, for anopen-hearth furnace: com prising a double-walled casing forming. a: space; for circulating a cooling liquid therethrough, a universal joint for angularly adjustably mounting said casing on a wall of said furnace, means for moving saidcasing for adjustment and for securing it in angularly adjusted position, a burner element within said casing having a tubular inner end'for flame-throwing alignment with an opening formed at the inner end of said casing, mounting means carried by said casing at the outer end thereof, cam means movably carried by said mounting means, actuating means for said cam means, means operable by said cam meansfor adjusting the position of said burner element within said casing, and means operable by said cam means for closing the opening formed at the inner end of said casing to make said burner inactive.

4. In a furnace, a plurality of burners disposed side by side and extending into the combustion space of said furnace through an end wall thereof, means for adjustably mounting each burner, means forming an elongated nozzlelike opening at the inner end of each burner which projects into said combustion space, fuel supply means in each burner for supplying a combustible fluid fuel to said nozzlelike opening through a plurality of individual relatively closely spaced orifices therein, means for supplying a fluid medium for intermixture with the fluid fuel supplied through said orifices to support ignition of said fuel so as to create upon ignition thereof a relatively flat and wide flame directed from said nozzlelike opening into said combustion space, means for adjusting said adjustably mounted burners to adjust said flames relative to the combustion space, means for retracting said fuel supply means of each burner, and means for plugging said nozzlelike opening of each burner while said fuel supply means is retracted.

5. A burner for a furnace comprising an outer cooling jacket extending into the combustion space of said furnace through an end wall thereof, means for adjustablymounting said burner, said cooling jacket forming an elongated 'nozzlelike opening at the inner end thereof which projects into said combustion space, fuel supply means in said burner for supplying a combustible fluid fuel to said nozzlelike opening through a plurality of individual orifices therein, mixture means for supplying a fluid medium for intermixture with said fluid fuel supplied through said orifices to support ignition of said fuel so as to create upon ignition thereof a relatively flat and wide flame directed from said nozzlelike opening into said combustion space, means for adjusting said adjustably mounted burner to adjust said flame relative to the combustion space, means for retracting said fuel supply and said mixture means, and means for plugging said nozzlelike opening while said fuel supply and said mixture means are retracted.

6. In a furnace, a burner comprising an outer housing, means for adjustably mounting said housing in a wall of said furnace, the inner end oi! said housing projecting into the combustion space of said furnace, said housing forming at such inner end an elongated nozzlelike flame ejection opening, a tubular member in said housing for supplying at the inner end thereof a fluid combustible fuel to said nozzlelike opening to create thereat a flame upon ignition of said fuel which is directed into said combustion space, a control member disposed at the outer end of said tubular member, actuating means for displacing said control member to move said tubular memher to adjust the position of the inner end thereof relative to said nozzlelike opening, a normally retracted plug disposed in said housing adjacent to and extending generally in parallel with said tubular member, and means controlled by said control member upon actuation thereof by said actuating means for displacing said plug to adjust the inner end thereof relative to said nozzlelike opening.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 854,798 Bunce May 28, 1907 1,020,955 Davidson et a1 Mar. 19, 1912 1,160,806 Wuestner et a1 Nov. 16, 1915 1,169,091 Melas Jan. 18, 1916 1,232,756 Best July 10, 1917 1,485,495 Eldred et al Mar. 4, 1924 1,571,179 Adams Feb. 2, 1926 1,800,669 Stillman Apr. 14, 1931 1,870,066 Olson Aug. 2, 1932 1,976,208 Agthe et al Oct. 9, 1934 1,980,891 Tonnar Nov. 13, 1934 2,011,554 Leutscher Aug. 13, 1935 FOREIGN PATENTS Number Country Date 843,045 France Mar. 20, 1939

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