US1544154A - Furnace arch construction - Google Patents

Description

June 30, 1925,

L. H. HOSBEIN FURNACE ARCH CONSTRUCTION Filed July 5,` 192; Sheets-Sheet 2 Patented `lune 30, 1925..

JUNITED- STATES PATENT OFFICE.

LOUIS H. HOSBEIN, CHICAGO, ILLINOIS, ASSIGNOR or CHICAGO, ILLINOIS, A

TO IVI. H. DETRICK COMPANY, CORPORATION OF ILLINOIS.

FURNACE ARCH CONSTRUCTION.

` e Application tiled July 5f, 1923. Serial No. 649,473.

To all whom zi't may concern:

Be it known that I,'LoUIs H. HosBEIN,

a citizen of the United States, residing at struction, ofvwhich the following is a speci- .ication A This invention relates to improvements in furnace construction, `and pertains particularly to the construction of portions constitutin'g the cover or roof portion of the furnace, commonly referred to as the furnace arch. In certain aspects, the present invention finds its principal utility in connection with furnaces of considerable width, where the area to be spanned by the arch is of more than ordinary extent. Such constructions are frequently met with in connection with the employment of apparatus for the burn-- ing of pulverized fuel, and constructions embodying the present invention find particular utility in installations of that character.

'Ihe invention has to do with a type of arch construction which is gaining increased popularity, commonly referred to as a suspended arch, as distinguished from a sprung arch, and it is one of the purposes of the invention to preserve certain recognized features of superiority pertaining to suspended arch construction While adapting it to installations of the sorts just referred to.

One of the objects of the invention is the provision of a suspended arch construction adapted to span areas of more than ordinary extent, by use of a minimum amount of material, and afford a construction wherein the metallic portions of the structure and the refractory portions thereof are so related as to give the latter the desired security of support yet limited freedom of movement, while affording the former maximum protection from the destructive` or injurious in fluences of heat from the furnace.

A further object of the invention is the provision of a construction of the sort specified wherein all portions of the arch construction subject to deterioration, and particularly the refractories which are located in the portions most subject to the disintegrating influence effective upon the structure, are susceptible of removal and replacement with facility, and without necessitating the displacement or disturbance of other portions ofthe structure-to any material extent. In this particular connection it is a further object of the invention to provide an arrangement which finds particular utility in connection with pulverized fuel feeding apparatus, whereby parts most subject' to disintegrating influences may be removed and replaced from the exterior of the furnace and without requiring its being put out of operation.

A further object of the invention is the provision of a construction having features which permit of the furnace walls being relieved of the load of the arch construction, either completely or to a desired extent, whereby the term of serviceability of the walls is increased, and repair of the Walls t facilitated. y

A further object of the invention is the provision of a construction of the sort speciied wherein a minimum variety in the number of different shapes of the component elements is required, and which has a wide range of adaptability, so that it may be applied to furnaces of great diversity in design, and installed in connection with ancillary apparatus of various sorts, such as fuel feeding apparatus or stoking apparatus of divers designs.

Other and further objects of the invention will be pointed out hereinafter, indicated in the appended claims, or ascertainable from the accompanying drawings forming apart off this specification. For the purpose of the present application I have elected to disclose the invention as embodied in a single design, butit is to be understood that the same is presented for illustrative purposes and hence is not to be accorded any effect or interpretation which will limit the invention which I purport to secure, short of its true .and most comprehensive scope in the art.

In the drawings,

Fig. 1 is a plan view of an arch embodying my invention, parts being broken. away or shown in section to illustrate the arrangement of under-lying portions;

Fig. 2 is a transverse section through the arch, such as might be taken on the line 2 2 of Fig. l; p

Fig. 3 is a longitudinal section, on a scale enlarged over that employed in Figs. l and 2 taken substantially on the line 3-3 of Figs. 1 and 2 but including also certain parts of the furnace and boiler setting occupying ositions above the arch and not shown in Eivs. 1 and 2;

igs.' 4 and 5 are details on the scale employed in Fig. 3, of certain parts of the arch assembly.

Fig. 6 is a detail showing a side' elevation of a supplemental tile hanger. v The nature of the invention will be most readily ascertained by reference to the drawings in detail. Let it be understood therefore that'the reference numeral 1 designates the front wall of the furnace and the numerals 2 side walls. These may be constructed in conventional fashion with inner facings of fire brick. `Together with the Hoor and the arch they constitute the closure of the furnace'chamber, which in this instance is utilized as a combustion `chamber associated with a steam boiler. The latter is here illustrated as of the Sterling type d in its setting includes the side boiler 'alls 4. As will be observed from an examination ofthe drawings, the furnace is of unusual width, particularly with reference to its length, a construction which may be employed to advantage with boilers of l the Sterling and other wide-banked types.

The use of a suspension arch, with its many advantages, in such an installation, requires that the arch structure be suspended across the wide expanse between the side walls.

`The requirements of such an installation present a serious problem, not onl because of the distance which the supportlng members have to span, but especially because of the heat to whichthey are exposed in addition to the heavy load which they have to carry. Not only is the roof of a furnace or combustion chamber continuously exposed to extremely intense heat, so that members lying above it are likewise ex osed to heat transmitted through it and ra iated from it, but the roof is subject to spalling or disintegration, whereby the amount of refractory material in the roof is reduced with more or less rapidity, so that it offers a gradually decreasing resistance to the passage of heat through it. y This subjects the metallic members above the refractory roof to the ever present contingency of becoming overheated. When they are loaded, such an occurrence will result in the bending of thev beams. Where the furnace is wide and the supporting beams consequently long, the possibilities of their becoming overheated 'are increased, becauseof the fact that radiation of heat from the beams takes place towards their ends, which are not over the heated arch; whence it results that the cooling of a long beam in that direction will be slow due to the fact that the heated portion of'v the beam is so much greater than the end portions in relatively cool location.

As a means of meeting the many requireent embodiment I illustrate this beam as.

made` up of a pair of joined I-beams 5. This rear end beammay be carried on the side walls 2, if they are of sutlicient stability, but- I prefer to extend this beam beyond the side walls and carry it on the columns 6 associated therewith. This rear end beam should be disposed as far above the level of the furnace roof as is feasible. At one or more points intermediate the side walls 2 the rear end beam is provided with brackets 7, to which are secured the rearward ends of longitudinal beams 8, which are here illustrated as made up of airs of channels placed 'back to4 back, wit intervening plates 9 depending below their lower flanges. The forward ends of the longitudinal beams 8`are suitably supported by a front beam 10 which acts as a spacer and columns 11 disposed outside the front wall. The elevation of the longitudinal beams 8 should be such that there will be substantial clearance' between them and the top of the furnace roof. Transverse bar supporting beams 12 extend intermediate the longitudinal beams 8, and between the outer partsl -thereof and the side walls of the furnace, `finding support on the latter and on the cured to the rear brackets 7 and the vlongitudinal beams 8. Due to the heavier load which it has to carry, and its subjection to somewhat greater heat, this beam 12 preferably is heavier than the beams 12. The hangers 14 find shiftable support on the beams 12 and 12 and carry arch bars 15 having upstanding web portions and lower marginal flanges 15 adapted for reception of the slotted tile 16, whereby the latter are pendulously supported from the beams 12 with their side faces in contact to form ortions of the arch which closes the top o the furnace chamber. The rearmost arch bars 15 have their tile engaging portions deflected upwardly, and carry wedge-shaped tile 16 to form a convex rear end or fan arch construction of the sort claimed in the co-pending application of myself and Raymond VD. Foltz, Serial No. 461,358.

In furnaces equipped for the use of pulverized fuel and supplied by pneumatic feedlll() of the front and rear margins of the apertures, and to fill the arch space between the apertures with tile supported independently of the arch bars 15. -As shown .in Figs. 1 and 3 the apertures are designated by the reference numeral 17. As shown in Fig. 1, intermediate'the apertures 17 I insert short suspension beams 18, secured at their ends to the adjacent beams 12. These suspension beams carry suspension bars 19 extending transversely of the arch in the portions between the, apertures 17 and suspension bars 19 in the portions between the side walls and the outermost apertures. These suspension bars have hook-like portions 19a adapted to engage over the lower flanges of the suspension beams 18, whereby the suspension bars are shiftable on the beams.,

These suspension bars may be slid on to the beam flanges at the ends of the latter where they are cut somewhat short from the beams 12 to which they are attached. l These suspension bars 19 and 19 have lower marginal flanges corresponding to those of the arch bars` and like them adapted to receive the slotted tile to fill the portions of the arch intermediate` the apertures 17, the tile thus supported heilig pendulously hung from the suspension beams 18. It will be observed however that whereas the courses of tile on the arch bars 15V run longitudinally of the furnace, the courses on the suspension bars 19 and 19 run transversely of the furnace. Consequently the broad side faces of tile 16 are presented at all four sides of the apertures 17.

lt is a frequently encountered experience that tile at the boundaries of these arch 'apertures are more subject to injuryand rapid disintegration than others in the arch structure, so that they may require replacement at much shorter intervals than other portions of the arch. ln order to avoid shutting down the furnace upon such contingencies, yet afford opportunity for making replacements in these tile, I provide flanged ledges 2O on the end lportions of the arch bars 15 and suspension bars 19 and 19 adjacent the apertures 17, the same forming hooks or shoulders and I provide supplemental tile hangers 21` having flanged hooked portions 21EL adapted to engage on the flanged ledges 20, so that the supplemental hangers will find support on the bars, and lower marginal flanges 21b corresponding to those on the bars and adapted to align therewith when the supplemental hangers are supported thereon. The length of the supplemental hangers and of their flanges 21,b is such as to accommodate the thickness of onc tile 16, so that'each of the tile hangers 2l forms a support for an individual tile, whereby the tile lnay be withdrawn upwardly out of the arch by lifting the hanger 2l upwardly out of its engagement with its supporting bar. By virtue of this arrangement any of the tile about the entire periphery of an arch aperture mav be replaced quickly and with facility while the furnace is in operation. In Fig. 3 the numeral 22 designates parts of the nozzle or hood of the pulverized fuel feeding apparatus, which parts are located to discharge through the apertures 17. By means of suitable brackets 24 or other connections, these parts of the apparatus may be properly mounted and supported upon members of the arch, such as the beams 5 and 12.

The construction affords the proper support for the curtain'u-'all at the rear ofthe arch, as the same may be carried not only on the rear ends of the rear arch bars l5, but also on the rear beam12 and the span beam 5. The loading of these metallic members with the curtain wall, and the resultant partial enclosure, of them, increase the possibility cf overheating and the resulting destructive strains. In order to decrease the possibility of overheating I provide for a particular construction of the curtain wall. This includes the provision of refractory cover tile 25 disposed on top of the rear beam 12 and affording a foundation upon which the curtain wall may be built thereabove. These cover tile 25 are laid spacedapart so that channels are provided intermediate them across the top of the beam 12, which channels are open at their front ends as well as at the rear, permitting a free circulation of air about the beam at closely located points. To the rear of the cover tile 25 the curtain wall is built up behind the beams 12 upon the shelves 15b of the rear end arch bars, said portion of the curtain wall covering the inner ends of the cover tile 25 and closing off the spaces between them from the interior of the furnace. Similar provision is made for the ventilation of the span beam 25 by arrangement of cover tile 26 thereon to support the curtain wall thereabove, said tile 26 being spaced apart to provide the Ventilating channels across the top of the beam and said channels being closed off from the interior of the furnace by the portions of the curtain wall carried on the beam 12.

From the foregoing it will be observed that by virtue of this construction l am enabled to dispose the span beam 5 at a substantial elevation above the refractory arch, and hence away from the zone of dangerous heating, and in that location I afford that beam ample ventilation for the purpose of carrying heat away from it. VVlth `the exception of the span beam 5, this construction eliminates the use of beams extending the full width of the furnace, and imposes the load of the refractory arch on beams which are shor-t and therefore still' as well as more adapted to rapid diffusion of heat. ln the event that through neglect the refractory arch should be permitted to burn through, resulting in the injury of any of the superjacent supporting beams, such beams can be readily removed and replaced at slight expense, and with disturbance to only the relatively small portion of the arch dependent on that ybeam for support. .lhe longitudinal beams 8, which are secondary in importance only to the span beam 5 are, like it, disposed at a substantial distance from the arch, and fully exposed in the air in such disposal that there may be free circulation about it and radiation from it. The bar supporting beams 12 and 1S are likewise supported clear of the arch and fully exposed to air circulation, while the beam 12 has special provision made for its ventilation. The arrangement for suspension of tile at the front and rear ends of arch in longitudinal courses, and intermediate tile in transverse courses, is of particular utility because of itsadaptability to different installations or modifications of an original installation. For example, if it were to become desirable to close certain of the apertures 17, such could be effected with facility simply by substitution of longer suspension bars and the addition of tile. The construction, moreover, permits the employment of relatively short arch bars, irrespective of the length of the arch. This has many advantages, including facility of installation and replacement, iexibility in the arch structure, superior' cooling possibilities and limitation of the arch area depending for support on a single supporting clement. Moreover, it permits the front and rear portions of the arch to be constructed Without limitation of one by the other. For example, in the front portion of the arch, -which in a certain installation may be relatively cool, it may be desirable to use wide tile and fewer courses than in the rear por-tion of the arch, which is subject to much greaterheat. The present construction permits the inclusion of any desired number of tile courses in one portion of the arch and a different nulnber in another portion. In addition to these, many advantages of construction lwill occur to one familiar with the art.

What I claim is:

1. In furnace arch construction, a span beam extending. across the furnace chamber, longitudinal beams supported by the span beam, arch supporting beams carried by the longitudinal beams and extending respectively across only a fraction of the width of the furnace chamber, refractories arranged to form the roof of the furnace chamber at a distance below the arch supporting beams, and means carried by the latter for suspensibly supporting the refractories.

2. In furnace arch construction, in combination, a span beam extending across the furnace chamber, longitudinally extending beams disposed at intervals across the furnace and supported by the span beam, arch supporting beams'carried intermediate adjacent longitudinal beams, refractories arranged to form the furnace roof at a distance below the arch supporting beams, and means carried by the latter for suspensibly supporting the refractories.

In furnace arch construction, in combination, a span beam extending across the furnace chamber adjacent the rearward limit thereof, longitudinal beams disposed at intervals across the furnace and supported at their forward extremities and by the span beam at .their rearward extremities, arch supporting beams carried by the longitudinal beams and each transversing only a fraction of the width of the furnace, individually movable tile arranged to form the furnace roof below the arch supporting beams, and means carried by the latter for .supporting Ithe tile.

4. In furnace arch construction, in combination, a span beam extending across the furnace adjacent its rearward limit, arch supporting members su )ported by said beam, refractories suspended from the arch supporting members in association to form the furnace roof below and spaced from the span beam, said furnace roof terminating to the rear of the span beam, a curtain wall rising from the rearward margin of the furnace roof and supported in part on the span beam, said curtain wall being constructed to afford Ventilating channels across the beam.

5. In furnace arch construction, in combination a span beam extending transversely of the furnace, arch supporting members carried thereby, refractories vsuspended from said arch supportingmembers to form the furnace arch, a curtain wall 4rising from said arch to the rear of Said beam and carried in part by the beam, said curtain wall affording Ventilating channels across the beam externally of the furnace.

6. In furnace construction, in combination, a beam extending transversely of the furnace, arch supporting members carried b v said beam, refractories suspended from said members to form the furnace. arch below said beam, a curtain wall rising from said arch to the rear of the beam, cover title supported on the beam and spaced apart to form Ventilating channels across the beam,

portions of said curtain Wall being carried on said cover tile.

7. In furnace construction, in combination, a beam extendingtransversely of the furnace, arch supporting membersv below said beam and supported thereby, certain of said arch supporting members including shelf portions arranged to the rear of the beam, refractories suspended from said arch supporting members to constitute the furnace roof, and a curtain wall rising from the arch to the rear of said beam and supported in part by the latter and in part on; Said shelf portions, said curtain wall afordin a bination of supporting beams, suspensionv bars pendulously hung therefrom and arranged in series in parallel relationship, the bars in all series being disposed in substantially the same plane with the bars of one series extending in converging relationship to the bars in another series, and refractories suspended on said bars in association.

to form a furnace arch.

10. ln furnace arch construction, the combination with supporting beams, of courses of refractories running in intersecting directions, and associated to form a furnace arch, said courses being interrupted to adord an aperture in the arch in their zone of intersection, and means penduloiisly hung from the beams and retaining the refractories in flexible suspension.

1l. lin furnace arch construction, in coinbination, supporting beams, suspension bars shiftably suspended thereon and extending in intersecting directions, and refractories suspended on said suspension bars in courses longitudinally thereof, aid refractories having side surface contact so as to form a gasconining furnace arch portion.

l2. ln furnace arch construction, the combination with supporting members, of suspension bars arranged in substantially the saine plane but extending in intersecting directions, refractories suspended in courses on tit) said bars to constitute furnace arch parts, said courses terminating adjacent the zone of intersection to ad'oi'd an aperture in the arch, and hangers supported at the ends of the bars about the aperture for sustaining the terminal refractories, said hangers being renpvable from the bars outwardly of the arc 13. ln furnace 'arch construction, a series of .suspension bars arranged in parallelV relationship, a second series of suspension bars arranged in parallel relationship, said second seriesl extending at substantially right angles to the first series but lying in substantially the same plane, said series being interrupted adjacent their projected zone of intersection, refractories suspended in courses on said suspension bars to form a gas-coniining arch adoi'ding an aperture Where the series of bars are interrupted, supplemental tile hangers supported on the ends of the bars about said aperture and individual refractories supported by. the respective hangers to form the boundary wall of the aperture.

14. In furnace construction, the combination of a span beam supported at its ends and bridging the furnace chamber, brackets carried thereby and extending rearwardly therefrom, rear beams supported on said brackets to the rear and below the span beam, arch supporting beams supported by the span beam in front of and below the saine, the respective arch supporting beams extending only part way the width of the furnace, and a refractory arch structure having its forward portion suspended from the arch supporting beams and its rearward portion suspended from the rear beams, said refractory arch structure forming a closure for the furnace at a distance below the span beam.

l5. In furnace arch construction, the combination of a beam at the front of the furnace, a beam at the rearward portion of the furnace, arch bars carried by said beams, tile suspended on said arch bars in courses extending longitudinally of the furnace and forming front and rear top arch portions, bar supporting beams connecting the aforementioned beams, arch bars suspended from said bar supporting beams, and refractories suspended on said arch bars in courses extending transversely of the furnace, said refractories forming top arch ortions continuous with those formed by t e tile.

16. ln furnace arch construction, in combination, a transverse beam at the front of the furnace, a transverse beam at the rearward portion of the furnace, longitudinally extending arch bars suspended from said beams, tile suspended on said arch bars in association to form front and rear top arch portions, longitudinal beams carried on said transverse beams, transverse arch bars supported on said longitudinal beams intermediate the front and rear arch portions, and refractories supported on said transverse arch bars to form top arch portions between the front and rear top arch portions.

17.fn furnace arch construction, in coinbination, a transverse beam at the forward part of the furnace, a transverse beam at the rearward part of the furnace, arch bars suspended from said beams, tile suspended from said arch bars to form front and rear top arch portions, longitudinal beams carried by said transverse beams, transversely extending arch bals supported on said longitudinal beams, refractories suspended on said transversely extending arch bars in a course running transversely of the arch intermediate said front and rear top arch portions, said transverse course beinginterrupted at intervals to al'ord openings through the arch, and fuel feeding apparatus associated with said opening,

18. In furnace arch construction, in combination, a transverse beam at the forward portion of the furnace, a transverse beam at the rearward portion of the furnace, arch bars suspended from said beams and exbars in a course extending transversely oi the furnace, refractories on said transverse arch bars being identical in form and size with refractories in said front and rear top arch portions and cooperating therewith to form a flat arch, said transverse course ot' refractories being interrupted to afford an aperture through the arch.

In testimony whereof I have hereunto signed my name.

LOUIS II. IIOSBEIN.

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