US1540070A - Furnace-arch construction - Google Patents

Description

June 2, 1925. v 1,540,,(3F Di 1.. H. HOSBEIN I FURNACE ARCH CONSTRUCTION Filed July 12, 1923 2 Sheets-Sheet 1 \mg i 'June 2, 192's. 0 0 1,540,070

' L. HOSBEIN FURNACE ARCH CONSTRUCTION Filed July 12,1925 2 e ts-shat 2 Patented une 2, 1925.

4 UNITED STATES PATENT, OFFICE.

LOUIS H. HOSBEIN, OF CHICAGO, ILPINOIS, ASSIGNOB TO M. H. DETBICK COMPANY, OF CHICAGO, ILLINOIS, A COR-PORATIGN OF ILLINOIS.

FURNACE-ARCH CO NSTRUC TION.

Application filed'Iuly 12, 1928. Serial No. 650,991. 7

To all whom it may concern:

Be it known that I, Loms H. HosBEIN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Furnace- Arch Constructions, of which the following is a speci fication.

This invention relates to furnace construction, particularly to the portion forming the roof of a furnace, and commonly referred to as the furnace arch. of the invention comprises the provision of a construction which will contribute to ignition and thorough combustion of fuel in the furnace; which is susceptible of installation and repair with facility; which will resistthe destructive or disintegrating infiuences of temperature changes, intense heat, erosion, and the like to which furnace linings, particularlyarch portions, are subjected; which is susceptible of wide modification and adaptationto a great variety of associated apparatusysuch as steam boilers v.and the like; which presents minimum lia- [bility of metallic portions to injury from llfiat of the furnace and which contributes to I economy in manufacture and maintenance A more specific object of the invention is the provision of a suspended arch construction designed particularly for use in connectionwith automatic stokers and having characteristics which induce the rapid coking and ignition of fuelupon its entering the furnace. In this connection it is afurther object of the invention to eliminate the so-called ignition arch as a. separate structural entity, and to incorporate it as' a prolongation or continuation of the main or .roof arch, thereby obviating the patch work heretofore resorted to to form the junction.

of the ignition and combustion arches and ZIVOldlIlg, their separation, such as might occur in various previous constructions, due to diflerences in expansion, or shifting of supporting members due to difi'erencein loading, and likely to result in leakage at points difficult of access and where important metallic structural members would ordinarily be exposed to. the injurious influences of escaping heat and gases.

Anot er particular object of the invention is the provision of'a construction for arches of the suspended type, including both an igs.

nition arch and a combustion arch, and per- Thegeneral purpose mitting, tothe maximum extent, the use of refractories of minimumcross-sectional size. Another particular object is the provision ofaconstruction for arches of the suspended type which will contribute in a desirable degree to the so-called glazing of the faces" of the refractories exposed to the fire, attaining thereby augmented resistivity to erosive influences.

A further object of the invention is the provision of, an improvementin suspended arch construction whereby the terminus of a suspended arch may be accommodated to boilers or other apparatus presenting a horizontally curved or otherwise irregular contour.

Other and further objects of, the invention will be pointed out hereinafter, indicated in the appended claims, or ascertainable from the present disclosure by one skilled in the art. In the accompanying drawings, forming a part of the specification, I have illustrated a structure in which the invenfor illustrative purpose only, and while I regard it as a preferred embodiment of the' invention, it is not to be accorded herein any eifect serving to limit the invention which I purport to secure hereby, short of itstrue and most comprehensive scope in the art.

In said drawings,

Fig. 1 is a longitudinal sectional elevation of a furnace arch shown in association with steam boiler and chain-grate stoker elements, which are illustrated diagrammati l y; V

Fig.2 isa transverse sectional elevation through the arch itself, such as might be taken on line 2-2 of Fig. 1;

, Fig. 3 is a fragmentary top view of the rear portion ofthe arch, such as might be observed on line 33 of Fig. 1; and" Fig. I is a detail, showingin perspective one of the drop hangers. W

' Furnace arches of the type known generally as suspended arches possess certain distinctive advantages of substantial utility, and it is with this type of arch that the present invention is concerned.- In the provision of the present improvements it 'has been my aim to preserve the characteristic advantages inhering in suspended arches as a class, to utilize these advantages to the fullest e t nt and to augment them with new advantages. What these advantages are will be pointed out or indicated in thelcourseforming portions of the furnace chamberand boiler setting, and that the reference character 11 designates parts illustrative of the location of a steam boiler to which combustion products are to be conducted from the furnace chamber; said boiler beinghere illustrated as of the Wickes type. The ref erence numeral 12 designates an automatic sides stoker of'the chain-grate type, here illustrated diagrammatically and including the r 12 from which fuel is fed into-the hoppe furnace th'rou h the fuel inlet 14 controlled by-the. adjusta le ate 15. These are all conventional arts 0 apparatus well known in the art.' erb'oiler and stoking mechanism 'are ancillary apparatus and do not in themselves form a part of my invention. Above the furnace chamber and across, the same are supported the beams 16, here shown as carried on side walls 10. Shiftably engaged with the beams 16 are the bar hangers 17, certain of which support the top arch bars 18 having. marginal flanges 18 and others of which support the curved arch bars 18. These arch bars extend longitudinally of the furnace and in aligned series. The top arch bars 18 are disposed at the upper and rearward portion of. the arch structure,

While the curved arch bars 18' are arranged in front of them'toward the forward portion of the furnace and curve downwardly from substantially "the plane of the top bars 18 toward the fuel; inlet '14.' The curved arch bars. 18' 'thus -present' concave lower with upwardly curved marginal flanges '18". At the front of the furnace, adjacent the fuel hopper, a series of drop hangers 19 are suspended from one of the beams 16. These are suitable rigid frame members, one form being illustrated in Fig. 4, wherein will be seenit includes a vertical web bound at the top by a connecting flange 19 pierced with apertures whereby the element may-be attachedto a hanger, the forward margin of the web bein laterally flanged as at 19" to afford latera ly opening slots. -A stop member 19 depends below the web at its forward margin. At its upper.

and rearward portion the-web is continued upwardly asa projection 19, bound on the forward margin by deflection of the flan e 19. At its lower and rearward margins t e web isprovided' with narrow lateral flanges.

19 of convex contour, and above them, after an interval 19, the rearward margin of the web is shaped with narrow lateral flanges 19 which are longitudinally curved inwardliof the hanger, said flanges continuing to t cent ends of said bars, the hangers beingsupported from one of the beams 16 by suitable attaching devices. The. location of the flanges 19 is such that they align with the flanges 18 ori. the bars. Refractory tile 20 having parallel sides are suspended in' courses on the bars 18 and 18',.being retained by the flanges 18 and 18" which are received into undercut slots in the outer ends of the tile, the side faces of the tile ing in contact so that a continuous fire resistant arch is provided as a top for the furnace chamber. In the intervals between the ends of adjacent bars. similar tile are suspended, they. being supported on bridge hangers .21 whlch have lower marginal flanges to enage in the slots of the tile and having proecting shoulders or ledges adapted to rest on the terminal tile which are supported on the bars, in such fashion that the tile carried on the bridge hangers will be retained in alignment and in contact with the tile to which they are juxtaposed. By withdrawal of the bridge hangers 21 and the tile carried by them, spaces will be afforded in the arch such asto permit the tile supported on the bars being slid off the latter and removed from thearch. The slots in the tile are of sufficient depth to permit the tile susended on the curved bars 18 taking slighty angular relationship so that the courses of tilewill conform generally tothe curvature of those bars. For the purpose .of taking up any excess divergence between the.

tile carried on the straight bars and those on thecurved bars, wedge-shaped tile 22, which taper toward their lower ends, may be in serted as desired. Likewise, upon the flanges 19 of the drop hangers, other parallel-slded tile 20 are suspended in courses aligning with those on the bars 18 and 18'. These courses of tile on the drop hangers conform to the contour of the curved flanges 19 so that their lower end faces form a conin my co-pending application Serial, No.

489,411, although it may be observed that they ma I be of,other sort, such as those i1- lustrate in the co-pending application of myself and NathanielD, Stevens, Serial No.

461,358; In the form illustrated herein the tile 24 are but one-half the width of the tile 20, so-that two ofthem are required to complete the width of the course. They are maintained on the flanges 1-9 by means of supplemental hangers 25, asdescribed-and claimed in my co-pendingapplication above contact their rearward sides, filling the space between them and the other tile on the flanges 19 This construction gives .the fire surface of the arch a contour curving reversely from the concave formproduced by the tile on the curved bar-s18 and on the V flanges 19 and provides a convex depending ignition archadjacent and sloping toward thefuel inlet. It will be observed that this convex portion adjacent the fuel inlet merges with an upbroken curve into the superj'acent concave form of the arch, so that the entire under surface of the arch formed by the ends of the tile has a continuous, unbr ken and regular contour.

In the construction of the rear end of the arch, in order to accommodate it to the above described withthe addition of pla'tes 23 which are inserted in the slots between the horizontally curved form of the boiler, as illustrated in Fig. 3, I provide the transverse beam 26. which has a bracket 27 forming a support for the inner ends'of diagonally arranged beams 28.- These in turn support a short bridge beam 29 extending parallel to the beam 26. The rear end hangers for the arch bars are carried by these beams 28 and 29, said arch bars being of graduated lengths, as illustrated in" Fig.3. At their rearward extremities these arch'bars carry nose brackets 30 secured thereto by wedges and-forming upwardly extending elongations of the bars terminating .in horizontally disposed shelves 30. These nose brackets, as described and claimed in my application above mentioned, have lateral arcuate flanges affording means of attachment for supplemental 'hangers25 to support a convex fan 'end construction made up of tile 24 like those on the drop hangers. Cover tile 33 are laid upon the shelves 305 to form a foundation course for the curtain walL.

nary fire brick resting on the tile 33.. It-

may. follow the marginal outline of -the cover tile 33 or may be built to overhang them so asto give the rear end ofthe arch a more regularfinish. By virtue of this construction the rear end of the arch may be brought into the desired proximity with the boiler tubes throughout the entire width of the arclnequalizing the distribution of gases to the boiler tubes. 1 5 l 1 The arch construction being assembled as flanges l9 of the drop hangers, to prevent fuel from the hopper falling on topof the frontend of .the arch, the function of'the arch in connection with theoperation of the furnace will be described as follows: The

stoking' apparatus being operated in the customary fashion to feed fuelthrough the fuel inlet opening 14, it will be observed that this fuel enters the furnace chamber in closeproximity to the depending arch surface formed by the tile 24. In this loca- Ition the fuel is subjected to the intense heat radiated and reflected b the arch and walls to that point from the uel and gases under combustion in the furnace chamber. The depending ignition arch concentrates this heat upon the fresh fuel with the result that its temperature is quickly raised to the point where its volatile constituents are driven off and the remaining solids soon ignited, meanwhile moving inwardly. As it progresses, the fuel is continued under the concentration of heat reflected by the concave portion of .the arch, so that its maximum combustion is reached at an early stage in its course of movement. It will be observed that the contour of the arch recedes rapidly upwardly from the fuel bed at the rear of the-narrow coking and ignition zone, so that the disposal of the refractories is out of the line of draft and atan elevation above the fuel bed such as to reducetheir susceptibility to the destructive action of the heat. It is to be observed moreover that this rapid rise inthe contour of the arch is accomplished without break in the regularity of thearch surface and without formation of apocket such as is ordinarily formedby the angular junction of a depending ignition arch witha top arch. .The present arrangement therefore contributes to thecombustion.efliciency of the furnace. One of the recognized advantages of the suspended arch resides inthe freedom of the individual tile for relative movement so that they may adjust-themselves incident to expansion and contraction of the structure, and thereby avoid extensive strains in it- The present invention makes further advantageous use of this char eacteristic to preserve the integrity of the arch, by providingan arrangement wherein, throughout. the entire extent of the arch wall, the refractories Wlll'fidjllSiL themselves to one another in such fashion asto preserve? the continuity of the'closure. I Instead of having an ignition arch subject tofcontraction and expansionin one plane, and a roof ar'ch'subjecttocontracfion and expansion in another, andseparate plane, whereby there islikelihod of opening up leaks between. the two, arches, the present invention provides aconstruction. whereinthencon tractlon, and expansion of, the roof arch and .the depending arch are interdependent. so there is no llne of cleavage along which'the structure might be inclined to open up. The construction therefore obviates the special arrangement and precautions heretofore requisite in the joining of the. top arch and the ignition arch.

As is well known in practice, the resistance of many kinds of refractories to the influences which produce spalling is dependent to an extent on a glazing or apparent fluxing of the "surfaces of the refractories exposed to the fire. It is important that such a glaze be produced on the refractories in a furnace arch immediately the arch is placed in operation, and that the glaze be preserved for the protection of the refractories. The provision of the present construction wherein the convex surface of the ignition arch merges gradually into the concave portion, and the latter, without interruption or break, into the flat top arch, affords an arrangement of the fire exposed surface which contributes to the formation of the protecting glaze uniformlyover the entire surface, as the end surfaces of all the ..fractory arch structure. The construction also facilitates repair or replacement of tile in the arch, as by withdrawal of the bridge hangers 21 injured or defective tile in any location in the arch may be removed and replaced without requiring extensive dismantling. All of the metallic elements in the structure are, afforded protection from the heat b virtue of the fact that they are located w ere the air has full access to them, the webs of the drop hangers as well as those of the arch bars being effective to conduct heat away from the portions of those members seated within the slots of tile, and radiate it into the air. The con"- struction is susceptible of incorporation in furnaces of any practical length, and width simply by provision of sup rting beams of proper length and use 0 the vrequisite number of arch bars 18 to afford the necessary length. V Features of construction herein shown but not claimed are claimed in co-pending application mentioned above, and in my copending application Serial No; 527,248.

What I claim is: I 1 1. In furnace arch construction, the combination of tile supporting members, tile suspended thereon "to form a flat arch portion, hangers supported adjaccnt'a wall of the furnace, wedge-shaped tile" suspended thereon toform a depending convex arch portion. adjacent the fuel inlet, curved supporting members, and tile supported thereon in association to form a concave arch portion having its inner surface merging with and forming a continuation of the.

inner surfaces of the convex and fiat arch portions.

2. In furnace arch construction, in combination, refractories supported in position to form a flat arch portion, curved bars suspended adjacent the same and curving downwardly therefrom, hangers supported adj acentthe lower extremities of the curved bars and tile supported on said hangers and bars to form an arch portion'of merging concave-convex contour in continuation of the flat arch portion.

3. In furnace arch construction, in combination, tile suspended over the furnace chamber to provide a flat arch portion, hangers disposed below the level'of the flat arch' portion, and adjacent the fuel inlet, wedge-shaped tile supported on said hangers form a convex 1' ition arch portion above the fuel inlet, ti e supporting members, disposed at different elevations between" the convex arch portion and the-flat arch portion, and tile suspended thereon to form a concave arch surface curving upwardly .from the convex arch surface into alignment with the flat arch surface.

4, In furnace arch construction, in com-- bination, tile suspended in association to farm a flat arch portion above the furnace chamber, hangers supported adjacent the fuel inlet, tile supported on said hangers to form an ignition arch extending inward-' ly and upwardly from the fuel inlet, certain of said tile being of Wedge; shape with their broader ends disposed toward the furnace chamber, tile supporting members arrangedbetween the ignition arch and the fiat arch,

and tile suspended thereon with their inner.

end faces formin 'a concave arch surface merging with the inner surface of the ignition arch and the inner surface of the fla arch. j

5. In furnace construction, a depending arch-portion comprising a plurality of laterally associated hangers, wedge-shaped tile suspended thereon with their broader end faces presented toward the furnace chamber, and parallel-facedtile suspended on said hangers aboveand contiguous to the wedge-shaped tile, said parallel faced tile being of substantiall the same length as the wedge-shaped t' e so that their lower end faces form an upward continuation of the arch surface formed by the inner ends of the wedge-shaped tile,

6. In furnace arch onstruction, the combination of a plurahelz of laterally associated hangers provid with flanges curved convexly toward the furnace chamber andsuperjacentflanges curved concavely toward the furnace chamber, wedge-shaped III tile suspended on the convex flanges so that theirinner ends form a salient arch portion, and parallel-faced tile suspended on the concave flanges so that their end faces form a sloping reentrant arch portion merging with the salient. arch partion.

7. In a furnace structure including the grate, the combination of tile supporting members arranged above the grate, tile suspended thereon to forma roof arch, and other tile suspended on the supporting members to form an ignition arch depending from the roof arch into proximity with the grate, the lower end surfaces of the tile in the ignition arch merging with-those of the tile in the roof arch.

8. In furnace arch construction, the combination of straightarch bars, tile suspended thereon in association to form a flat arch portion, curved arch bars in alignment with the straight arch bars, tile suspended thereon with their lateral faces in contact to form a. depending concave arch portion, tile supports arranged in alignment with said curved arch bars, and tile suspended thereon with their lateral faces in contact to form an ignition arch portion, the tile on aligned tile supports and arch bars constituting continuous cources with the lower end faces of contiguous tile flush.

9. In furnace arch construction, the combination with lateral supports, of beams supported thereon and extended diagonally above the furnace chamber, arch bars suspended from said beams and terminatin at graduated point-s longitudinally of the furnace'atapproximately uniform distance from the beams, and refractoriessuspended on said arch bars in association to'form the furnace arch, the graduation in the length of the arch bars contributing variation in the rearward extent of the arch at different points transversely thereof.

10. Suspended arch construction comprising the combination with lateral supports, of a beam carried thereon and spanning the furnace chamber, diagonal beams supported ported thereon and extending diagonally above the furnace chamber, arch bars suspended from said beams and extending to diiferentlengths longitudinally of the furnace but having substantially uniform overhang beyond the beams, refractories suspended on said arch bars to form a top arch, the refractories on different arch bars terminating at different points longitudinally of.the furnace. and an apron wall built upwardly from the rear ends of the arch bars.

12. In a boiler furnace installation including a boiler of irregular front contour, the combination of arch bars of different lengths terminating in association with the boiler, refractories supported on the arch bars to form a furnace roof for conduct-ing combustion products to the boiler, and a beam extending diagonally above the furnace chamber and affording support for the arch bars at substantially uniform distance from their boiler ends.

In testimony whereof I have hereunto signed my name.

LOUIS H. HOSBEIN.

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