US2339477A - Furnace wall burner - Google Patents

Description

Jan. 18, 1944. F, 0, mass ETAL FURNACE WALL BURNER Filed Jan. 9, 1941 2 Sheets-Sheet 1 R. 8.: 5mm R.M Y m m mm .m m n mm A jam. 1,, 3944. F. 0. HESS ETAL v 2,339,477

FURNACE WALL BURNER Filed Jan. 9, 1941 2 Sheets-Sheet 2 Patented Jan. 18, 1944 FURNACE WALL BURNER Frederic 0. Hess, Germantown, and Joseph Ehlinger, Conshohocken, Pa., assignors' to The Selas Company, Philadelphia, Pa., a corpora- I tion of Pennsylvania Application January 9, 1941, Serial No. 378,728

Claims. (Cl. 158-7) The general object of the present invention is to provide an improved furnace wall burner constructiom More specifically, the object of the invention is to provide improvements in a furnace wall burner arrangement of the commercial type disclosed in the prior Patent 2,287,245, granted June 23, 1942, on,the application, Serial No. 205,681, filed May 3, 1938, of Frederic O. Hess, one of the applicants herein. In the burner disclosed in saidprior application, an accurately formed combustion chamber block of refractory material is permanently incorporated in a furnace wall. Said block is formed with a combustion chamber or space open at its inner end to the furnace chamber, and is formed with a passage opening into, and extending outwardly from the combustion I chamber, and through which replaceable burner parts may be inserted and removed from the outer side of the furnace wall.

O ne specific object of the present invention is to modify the capacity of 'the combustion chamber wall to radiate heat and to maintain ignition,

described, with improvements which facilitate the removal of burner nozzle and associated conduit parts for inspection, repairs or replacement, and which will accommodate the relative thermal expansion and contraction of different parts of the furnace wall and burner construction, and

will minimize the risk of objectionable gas leakage,

A further specific object of the present invention is to provide a burner. unit adapted to insertion in a furnace wall and comprising a ceramic body portioma" metallic outer end portion, and a spring whichin the normal use of the burner comes between the ceramic body and metallic outer portions to snugly hold the ceramic portion of the burner unit inv engagement with a seat formed for the purpose in the furnace wa1l, and in which said ceramic and metallic portions and spring may be factory-assembled into a unit conveniently adapted to b shipped as a unit and inserted in the furnace wall asa unit.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however,'its advantages, and specific objects attained. with its use, reference should be had to the accompanying drawings and descriptive matter in which we haveillustrated and described a preferred embodiment of the invention.

Of the drawings:

Fig. 1 is a-section through a portion of the i v furnace wall and burner mounted therein;

Fig. 2 is an elevation of a portion of the burner, as seen from the inner side of the furnace wall; and

Fig. 3 is a section on the line 3-3 of Fig. l.

' Fig. 4 is a partial section taken similarly to Fig. 1 illustrating a modification; and i Fig. 5 is an outer end view of the burner shown in Fi 4. i

In the construction shown in Figs. 1-3, A represents the refractory body portion of the wall of a furnace adapted to be heated in whole or in part, by one or more, usually more, burners mounted in the furnace wall. The improved furnace'wall burner construction shown in the drawings comprises an accurately molded combustion chamber block of ceramic material B, incorporated in the ,furnace wall and forming a portion thereof. Cusand with a central passage B coaxialwith, and

tomarily, and as shown, theblock B is rectangu-v lar in outline, and is formed at its innerside with a cup-shaped combustion chamber or space B,

extending outwardly from, the combustion chamher. At the outer side of the block B, the passage B opens into a burner well or passage C, extending-to the outer face of the furnace wall. As shown, the furnace wall comprises an outer metallic armor or casing D, Advantageously{ the block- B is permanently anchored in the furnace wall proper by a suitable high temperature fire brick cement F, adapted to firmly bond the block to the adjacent portion of the furnace wall.

As'shown, the combustion chamber B comprises an outer portion having a conical sur rounding wall B and a cup-shaped inner portion, the wall of which is roughened, as shown, by providing it with a series of ribs 3: Each rib has a cylindrical inner wall coaxial with the passage B and a second wall tranverse to the passage B The cylindrical inner walls of the ribs B progressively increase in diameter and axial extent as the distance from the inner face of the block B diminishes. With combustible I mixture jets ,discharged into the combustion space in the known manner hereafter described, the ribs B" H comprises a body portion shown in'Fig. l as cemented in place in the inner end of the passage I, though it may be threaded into the inner end of the passage I as is the tip member HA shown in Fig. 4. The tip H has an enlarged head at its inner end, which overlaps the inner end of the holder I and comprises an inner portion H and an intermediate portion H The diameter of the portion H is less than that of the part peratures, they aid in maintaining ignition in operation with high burner pressures and velocity. In the preferred form of the present invention, we advantageously form different portions of the block B of different refractory ceramic materials, each of which is especially desirable for use in its particular location in the block. The different materials are suitably compacted and worked into a unitary refractory mass by a molding operation in which the block is given its shape. As shown, the portion B of the block which surrounds the outer end portion of the combustion chamber B may advantageously be made of refractory material having especially high'heat-shock resisting properties. The annular portion B surrounding the portion B may well have somewhat better heat insulating properties than the material of the portion 3 The annular portion B of the block extending from the outer side of the portion B to the outer side of the block, may advantageously have still higher heat insulating properties than the material in the portion B and the central portion B of the block at the outer side of the portion B is advantageously formed of a material having still higher heat insulating properties. Advantageously and as shown, the outer end, or mouth of the passage B is lined by a body G of hard refractory material which is accurately formed and is wear resistant. The body G may well be a preformed and prefired body of porce-' lain, incorporatedin the block in molding the latter prior to the firing operation which gives the block portions 3 -3 their final form and character and unites those portions to one another and to the block part G. e

Jets of a combustible mixture of air and gas are delivered to the combustion chamber B" by a burner nozzleelement comprising a burner tip member H and a tubular burner tip holder I, each of refactory ceramic material. The tip holder I is axially disposed in the passage and is provided intermediate its ends with a shoulder I, having a radial surface which fits against the porcelain or other hard refractory insert G. The surface of the latter, engaged by the shoulder I, may be accurately ground after the block B is formed. Ordinarily, the portion of the tip holder I at the inner side of its shoulder 1' substantially fills the passage 3 through the block B. Advantageously, however, the cross section of the burner well C is sufficiently larger than that of the outer portion of the burner tip member I to provide ample clearance between the latter and the wall of said well to accommo- H but is greater than that of the body portion. As shown, the inner end of the axial passage 1 is outwardly flared sharply to form a conical seat engaged by the inner conical side of the head portion H of the tip member H.

The peripheral surface of the body portion and portion H of the burner tip member H is formed with channels or grooves H which extend longitudinally of the member along the full length .of its body portion. The channels H terminate ture when supplied at a suitable pressure to the outer end of the passage I is discharged into the combustion space in jets inclined outwardly away from the axis of the burner and generally parallel to the adjacent portion of the combustion chamber wall. As those skilled in the art will recognize, the burner shown is-thus of the extensively used duradiant type, disclosed and claimed in Patent No. 2,215,079, granted .September 17, 1940. 4

In the heretofore more usual form of the Duradiant burner, the inclined channel portions II extend to the periphery of the portion ofthe tip member H. In Fig. 1, however, the head portion H projects laterally beyond the outer ends of the orifice portions H alongside the jets issuing from the latter and is thereby heated to incandescence even when the burning jets are short and small and the incandescent portion of the burner tip member is man advantageous position to maintain ignition. The special burner tip construction shown in Fig. 1 is especially desirable because it facilitates the maintenance of ignition, particularly under light load operation with a combustible mixture including a slow burning gas.

The :burner tip member H may be inserted and removed with the tip holder member I through the burner well C in the furnace wall when the maximum tip holder diameter is not greater than the minimum diameter of the passage B as is the case in the construction shown in Figs. 1-3. However, it is-notaiways necessary to shape the burner tip and tip holder to permit the tip to be I inserted and removed through the passage 1B.

since, in many cases, it is practically feasible to remove and replace the burnertip member' from or through the furnace chamber. I As shown, the conduit means through whic the combustible mixture is supplied to the outer end of the tip holder passage 1 comprises a tubular'metallic coupling part J having a plain,

, inner, tubular portion extending into the passage I and cemented to the wall of that passage and having an outer end portion J which is of increased diameter and corrugated, and forms an integral, expansible bellows portion of the member J Said "bellows portion is connected at its outer end to an annularfiange or end pert J, which, as shown, is clamped against the inner side of the'outer end wall K of a spring and bellows chamber K in a metallic burner plate member K. The latter is formed at the inner end of the chamber K with an internal flange portion K. The member K is also formed with an outwardly extending flange portion K which, in normal use is clamped against the metallic furnacecasing D, at the margin of the opening D formed therein and surrounding the corresponding burner seat in the furnace wall. The plate member K is formed at its outerside with a hollow boss K internally threaded to receive the the member H. At its outer end the tip holder IA is connected to a tubular metallic coupling,

. part JA having its axial passage enlarged at'its end of an external supply pipe L. Q

or bearing member 0 which surrounds the body portion of the member J and abuts against the outer end of the ceramic tip holder I. Advantageously, and as shown, the member 0 is formed with fingers or projections O which in'the working condition of the apparatus shown in Fig. 1, extend in front of and are spaced outwardly away from the internal burner plate flange K In the shipping, or transportation condition of the burner unit comprising the parts H, I, J, K, L, M and O, the projections O are held inengagement with the flange K by the spring M the tension of which is sumcient to prevent accidental displacing of the parts in transportation. To permit the ready, factory assemblage -of the parts, the internal flange K? is' formed with suitably disposed radially extending openings K shown in Fig. 3, one for each of the different projections 0' and through which the latter are passed in the initial. factory assembly of the unit. After the projections O are moved through the slots K the member 0 is rotated about its own axis relative to the burner plate member K to move the projections 0 out of reg-v istry with the openings K An important, practical advantage of the construction shown in Figs. 1 to 3, is that it prevents substantial movements of the outer portion of the furnace wall relative to the block B and longitudinally and transversely ofthe burner inner 1 end to form a socket in which the outer end of the ceramic tip holder IA'may' be ccmented. As shown, the socket'wall is formed with openings J to facilitate the cementing operation. The outer end portion of the member JA is of reduced diameter and is externally threaded and has screwed onto it a metallic ball joint element P formed with an axial passage and with a spherical outer end surface P. The flexible metallic pipe R has its inner end,

secured in the outer end of the'axial passage of the member P and has its outer end secured in the enlarged inner end of the bore of a nipple element S which extends through a member KA :bolted to a removable burner plate KB, and

, forming a closure for an aperture in said plate in burner well C is formed by the registering axial bores of tubular tiles C C and C arranged end to end and extending from the outer side of the block B to the outer side of the furnace wall.

Advantageously, to accommodate the unequal thermal expansion and contraction of the burner parts and to reduce the gas leakage risk, a nonaxis which may be produced by the stresses of operation, from interfering with the burner efrefactory portion of the furnace wall in position to radiate heat to the enclosing metallic casing element K and to be correspondingly cooled. This is especially important when the refractory portion of the furnace wall is relatively thin so that the temperature of its outer portion may be appreciably higher than when the furnace wall is thicker.

In Figs. 4 and 5 we have illustrated a form of our invention including a burner block B mounted in the furnace wall adjacent the furnace chamber, as in the construction first described. Mounted in the passage B of the burner block B is a burner tip holder IA which differs in form from the previously described member I, in that it is internally threaded at its inner end to receive the burner tip member HA.

' The latter omits the special head portion H of hardening, high temperature cement W is inserted in the joints between the adjacent end to end tiles C C and C and between the inner end of the tile 0 and the block B. Advantageously,

-the block B in this construction, as in the construction first described, is permanently incor-' porated in the furnace wall by a suitable, high temperature, fire brick cement W adapted to firmly bond the block to the furnace wall. As shown, a gasket W is interposed'between the outer end of the outer tile C and the burner plate KB and the latter is formed at its inner Associated with the member KA are stufllng box provisions for establishing a gas tight joint between the member KA and the cylindrical portion of the member S passing through the'member KA. As shown, those provisions comprise a flexible packing X pressed into a conical enlarg'ement of the inner end of the passage through the member KA by a sealing washer X which fits about the cylindrical body portion of the member S and is pressed against the packing by 'a spring member S. The spring MA acts through the washer MA on the adjacent outer end of a tubular metallic member Q which surrounds the flexible pipe-R and is provided at its inner end with a bearing part Q having a spherical bearing surspherical surface P may supply combustible mixture to each of a plurality of burners, and is mounted in the furnace wall, through a branch including a flexible pipe section U, a regulating valve U union U and uniform character.

form of burner disclosed, the combustion of the pipe connection to the burner.

and an elbow U To prevent the nipple S from transmitting torsion stresses to the tip holder IA and connecting parts within the burner well C,

we advantageously provide a spline connection between the casing part KA and the nipple S. As shown most clearly in Fig. 5, the spline connection is formed by flattening the sides of an outer portion of the nipple S and by straddling the flattened portion of the nipple by the bifurcated portion of a locking plate member T which is formed with an open ended, slot T of a width smaller than the full diameter of the nipple S but large enough to receive the flattened portion of the nipple. As shown, the locking plate T is bolted to, the closure part KA.

As will be apparent to those skilled in the art, the construction shown in Figs. 4 and 5 possesses the general operating advantages mentioned above as obtainable with the construction shown mechanical strength. In such a wall, the use of the tubular well tiles C C and C which may be formed of relatively strong ceramic material, is especially desirable.

For a full appreciation of the practical merit and advantages of the present invention,- account should be taken of the operating conditionsv for which our improved furnace wall burners were devised and are adapted. Such burners are customarily, though not invariably, used in heating, furnace chambers to very high temperatures. In some cases, the furnace chamber temperature attained is as high as 2900 F. In many uses of the burners, it is highly important, also, that the products formed by the combustion of the combustible mixture shall be of a predetermined With the type and mixture jets supplied to the combustion chamber are completed in that chamber, and the products formed are thus predetermined by the composition of the mixture supplied to the furnace, provided there the wide range of temperatures to which they are subjected, tends to wall cracks and open Joints, lateral and consequent leakage through the furnace wall. The temperature range. may extend from a combustion chamber temperature of 3000 F. or so to atmospheric temperature inthe case of the outer end of the flexible metallic Each 'of the constructions illustrated is well adapted to accomdate the relative thermal expansion of the burner parts, resulting from the wide temperature range and to maintain gas tight joints so as to prevent the leakage of atmospheric air into the combustion chamber through the passage B. Each construction is also well adapted to remain in good operative condition notwithstanding lateral displacement of the metallic wall armor and external supply piping relative to the burner block B.

Operation with the high burner' temperatures obtained without objectionable local overheating in the combustion chamber, requires extreme accuracy in form and disposition of the combustion chamber wall and the burner nozzle orifices through which the combustible mixture Jets are discharged into the combustion chamber. That accuracy is insured with applicant's construction, by the use of a molded combustion chamber block which can be formed with a high degree of accuracy, and by the use of associated burner nozzle parts which are practically possible of construction with the accuracy required for their interchangeabl'e use. Their capacity for interchangeable use is practically essential since, with the extremely high temperatures experienced, there is an inevitable need for the frequent replacement of burner tip members, and for the occasional replacement of tip holder members. With each of the described constructions, the burner tip holder and associated supply conduits may be removed and accurately replaced quickly and easily. To effect their removal, it is necessary only to open the union U and to take out the bolts normally securing the closure member K to the plate D in Fig. 1 and the bolts normally securing the closur plate KA to the plate KB in Fig. 4.

This application is a continuation in part of our application Serial No. 365,440, filed November 13, 1940, and containing claims on a novel burner tip construction disclosed but not claimed herein.

While in accordance with the provisions of the statutes, we have illustrated and described the best forms of embodiment of our invention now known to us, it will be apparent to those skilled in the art that changes may be made in the form of the apparatus disclosed without departing from the spirit of our invention, as set forth in the appended claims and that in some cases certain features of our invention may be used to advantage without a corresponding use of other features- Having now described my invention, what we claims as new and desire to secure by Letters Pat- 'en 1. The combination with a masonry furnace chamber wall formed with a burner passage opening through said wall to the furnace chamber and providing a burner seat at the inner end of an outer portion of said passage, of a tubular burner body mounted in said seat and insertable therein and removable therefrom through the outer end of said passage, and a conduit supplying combustible fluid to said burner body comprising a section adjacent and rigidly secured to the outer end of said burner body and a flexible section more remote from said body and having its outer end secured to said wall and in fixed relation therewith.

2. The combination with a furnace chamber wall comprising a body portion of ceramic material-and an outer metallic-casing, and formed with a burner passage opening through said wall to said furnace chamber and providing a burner seat at th inner end of an outer portion of said passage, of a tubular burner body mounted in said seatand insertable therein and removable therefrom from the outer .end of said passage, and a combustible fluid supply conduit having one end secured to said burner body and having its other end secured to said casing and comprising a flexible intermediate portion.

3. The combination with a masonry furnace chamber well formed with a burner passage the inner end of anouter portion of said opening through said wall to the furnace chamber and formed withlan annular burner seat at the inner end of an outer portionof said passage and surrounding an intermediate portion of said passage which is of lesser diameter than'said outer portion, of a tubular burner body mounted in said seat and insertable therein and removable therefrom through the outer end of said passage, resilient means holding said burner body in said seat and means for supplyingcombustible fluid to said burner body comprising a flexible supply conduit section.

4. The combination with a masonry furnace 'chamber wall formed with a burner passage opening through said wall. to the furnace chamber and formed with an annular burner seat at the inner end of an outer portion of said passage and surroundingv an intermediate portion of said passage which is of lesser diameter than said outer portion, of a tubular burner body mounted in said seat and insertable therein and removable therefrom through the outer endof said pas.-

sage, and means for supplying combustible fluid to saidburner body comprising a pipe section rigidly connected to said wall and a flexible supply conduit section extending between said pipe section and burner body. a

5. The combination with a masonry furnace chamber wall formed with a burner passage opening through said wall to the furnace chamber and formed with an annular burner seat at the inner end of an outer portion of said passage and surrounding an intermediate portion of said passage which is of lesser diameter than said i outer portion, of a tubular burner body mounted and extending across the outer end of said passage and formed with an aperture opening to said' passage, and means for supplying combustible fluid to said burner body comprising a flexible pipe connecting said part and burner body and communicating with said aperture.

'7. The combination with a masonry furnace chamber wall, formed with a burner passage opening through said wall to the furnace chamber and formed with anannular burner seat at passage and surrounding an intermediate portion of said passage which is of lesser diameter than said outer portion, of a tubular molded refractory burner body mounted in said seat and insertable therein and removable therefrom through the outer end of said passage, a metallic part detachably secured to said wall and extending across the outer end of said passage and formed with. an

aperture opening to said passage, a supply pipe extending into said passage through said aperture, joint packing means surrounding said supply pipe at the inner side of said part, and resilientmeans acting betweensaid last-mentioned means and burner burner body and tending to move each away from the other.

8. The combination with a masonry furnace chamber wall formed with a burner passage opening through said wallto the furnace chamber and formed with an annular burner seat at the inner end of an outer portion of said passage and surrounding anintermediate portion of 'said passage which is of lesser diameter than said outer portion. of a tubular molded refractory burner body mounted in said seat and insertable therein and removable therefrom through the outer end of said passage, a tubular metallic structure cemented to the outer end of the'burner body and formed with an outwardly facing spherical surface, and resilient means engaging against said surface and holding said burner body against said seat. i

9. The combination with a masonry furnace chamber wall formed with a burner passage opening through said wall to the furnace chamber and formed with an annular burner seat at the inner end of an outer portion of said passage and surrounding an intermediate portion of said passage which .is of lesser diameter than said outer portion, of a tubular molded refractory burner" body mounted in said seat and insertable therein and removabletherefrom through'the outerend of said passage, a tubular metallic structure cemerited to the outer end of said passage and formed with an outwardly facing spherical surface,aflexible combustible supply pipeconnected I to said metallic part, and resilient means engaging against said surface and holding said burner body against said seat.

10. The combination with a masonry furnace chamber wall formed with a burner passage opening through said wall to the furnace chamber and formed with an annular burner seat at the inner end of an outer portion of said passage and surrounding an intermediate portion of said passage which isof lesser diameter than said outer portion, of a tubular molded refractoryburner body mounted in said seat and insertable therein and removable therefrom through the outer end of said passage, a metallic part de-' tachably secured to said wall and extending across the outer end of said passage and formed with an aperture opening to said passage. and means supplying combustible fluid to said'burner body comprising a rigid supply pipe section extending into said passage through said aperture and in splined engagement with said metallic .part and a flexible pipe connecting said burner body.

11. A masonry furnace chamber wall including in combination a molded block of refractory material permanently mounted in the inner por tion of said wall and having a passage whichextends through said block and through the portion of said wall at the outer side ofsaid block, said block comprising portions differing from one another in composition and including a preflred a porcelain burner seat portion surrounding the outer end of the passage in said block and integrally fired to the other portions of 'the block subsequent to the block molding operation.

12. The combination with a masonry furnace chamber wall including a. molded block of refractory material permanently mounted in the inner portionof said wall and having a passage -which extends throughsaid block and through the portion of said wall to the outer side of said block, said block comprising integrally connected portions differing from one another in composition and being formed with a burner seat surrounding the outer end of the passage in said block, of a tubular burnerbody seated in said seat part and. v

body seated in said seat and insertable in and I removable therefrom throughthe outer end of said passage, and means for supplying a comsaid burner body.

14. Thecombination with amasonry furnace chamber wall. including a molded block of refractory material embedded in a portion of said wall adjacent the furnace chamber and formed with a passage extending between the furnace chamber side and the opposite side of the block, and including a plurality of hollow tiles arranged end to end between the outer side of said wall and the outer sidetpf said block, said tiles having their bores coaxialYwith one another and with said passage, and of greater diameterthan said passage at the outer end of the latter, of a tubular burner body seated against the outer side of said block with its bore coaxial with said passage and insertable into and removable from its position of engagement with said block through the bores of said tiles, a metallic outer wall part engaging the outer end of the outer tile, means for supplying combustible fluid to said burner body extending through said metallic wall portion and through the bores of said tiles, and

means acting between said metallic wall part and said burner body to resiliently press the latter against said block.

15. The combination with a masonry furnace chamber wall formed with a burner passage opening through said wall to the furnace chambustible fluid to said combustion space through 15 her and providing a burner seat at the inner end of an outer portion of said passage, of a tubular molded refractory burner body mounted in said seat and insertable therein and removable therefrom through the outer end of said passage, and

20 means for supplying combustible fluid to said burner body comprisinga'tubular metallic element comprising an inner end portion rigidly secured to the outer end of said burner body and an outer end portion rigidly attached to an outer 28 portion or said wall and an intermediate portioncircumferentially corrugated to form a flexible portion of said element.

X FREDERIC O. HESS.

JOSEPH EHLINGER.

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