US1807408A - Furnace construction - Google Patents

Description

May 26, 1931, H.- HOSBEIN FURNACE CONSTRUCTION I Filed July 5 1923 2 Sheets-Sheet 1 y 26,1931. L. H. udss-Em 1, 07,408

FURNACE CONSTRUCTION Filed July 5. 1923 2 Sheets-Sheet 2 Patented May 26, 1931 UNITED STATES PATENT OFFICE LOUIS H. HOSBEIN, OF CHICAGO, ILLINOIS, ASSIGNOR TO M. H. DETRICK COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS FURNACE CONSTRUCTION Application filed July 5, 1923. Serial No. 649,472.

This invention relates to furnace construction, and pertains particularly to ylIlTlPIOVG ments in the construction and assembly of parts comprising and associated with the s-structures forming the top closure for the furnace chamber and commonly referred to as the ffurnacearch.

The invention relates to that type of furnace arches commonly designated suspended arches to distinguish from sprung arches. The use of suspended arches in various sorts of furnaces'is becoming rapidly more'general, and arches of that type are recognized as possessing certain distinct features of advantage over othen types. It is one of the purposes of the present invention to incorporate certain improvements into the con-,

struction of arches of this type, or into furnace parts associated with arches of this type,

while maintaining all of the recognized advantages which suspended arches possess.

The general purpose of the invention is the provision of improved construction designed to betterthe stability of furnace structures and increase the term of service of suspended arches and other refractory portions associated with them.

-Another object of the invention is the provision of a construction designed particularly to accommodate the expanding and contracting movement of the arch in response to changes in temperature, without opening joints between the arch and portionsof the setting with which it is associated.

Another object is the provision of a construction of increased flexibility in the particular that it may be readily accommodated to varied conditions in the furnace or-boiler setting. 1 A further object of the invention is the provision of a construction whereby the arch and 'superjacent curtain wall structures are associatedin such fashion as to facilitate repair of the respective parts independently.

Another specific object of the invention is the provision of a construction whereby the arch may contribute to the support of the curtain wall without subjecting: the arch structure itself-to the weight of the curtain 0 wall.

the appended claims, or ascertainable from the present disclosure by one skilled in the art. It will be observed that for the pur-.

pose of this application I have disclosed herein one formin which the invention may be embodied, but it is to be understood that the same is here presented for the purpose of illustration only, and hence that it is not to be accorded any interpretation hav-ingthe effect of limiting the invention which I purport to secure hereby, short of its true and most comprehensive scope in the art.

In the accompan ingdrawings, forming a part of this speci cation, Fig. 1 represents a longitudinal sectional elevation taken through the upper portion of a furnace embodying my invention, parts illustrative of the stoker mechanism being shown diagram matically.

Fig. 2 is a top View such as would be observed on line 2-2 of Fig. 1.

Fig. 3 is a detail in the nature of a perspective illustration of one of the wall bra ckets.

The nature of the invention will'best be understood by reference to these drawings in detail, whence it will be observed that the reference character 10 designates side walls which define the lateral limits of the furnace chamber and which, in the present instance, are illustrated as constituting sup orts for the arch structure. One of the a vantages of the present construction, however, is that the arch and, curtain wall structure may. be supported independently of the side walls as on suitable columns, so that the side walls may be relieved of that load. The parts designated b reference characters 11 and 11a are inten ed to illustrate parts representing the grate and hopper of a chain grate stoker mechanism by which fuel is fed into the furnace chamber through the feed inlet 12. The invention is not limited for its utility, however, to use with any particular stoking mechanism, or to automatically stoked furnaces. At the front of the furnace there is a transversely extending beam 14, which is here illustrated as formed of conj oincd channel and I -beam members; and at the rear portion of the arch a transversely extending span beam 15, here illustrated as formed of rigidly conjoined I-beam members. Both of these beams 14 and 15 span the furnace chamber, and are supported at their ends on the furnace walls 10 or otherwise. They preferably are spaced at a substantial distance from the location of the refractory arch portions which close the furnace chamber. Extending between these two beams 14 and 15, and connected at its extremities thereto, is a stay member or carrier beam, 16. There may be a plurality of these, depending on the width of the furnace or other considerations. Supported on the carrier beam 16 are the hanger beams 17, which extend transversely of the furnace intermediate the beams 14 and 15. By means of hangers 18 shiftably carried on the hanger beams 17, tile supports '19 are suspended above the furnace chamber, said supports preferably taking the form of arch bars extending longitudinally of the furnace chamber and provided with tile retaining portions, here illustrated as laterally directed flanges 19a. Tile 20 are suspended on these tile supports with their side faces in contact so that in their association they form a continuous flat closure roof or arch for the furnace chamber. As a. means for protecting the stoker mechanism, or improving the operation of the furnace, a front drop arch of the form illustrated may be employed, al-

though the use of such a construction is not essential to other features of my invention herein claimed. Features of this drop arch or ignition arch construction form the subject matter of and are claimed in the patent of myself and Nathaniel D. Stevens. Number 1,628,284, and my U. S. Patent 1.544.580. In the embodiment herein illustrated, however, the drop archcoristruction includes certain new and advantageous features not included in the earlier patents. The new construction includes a series of drop hangers 21 suspended across the front of the furnace from the beam 14, said drop hangers being provided with upwardly deflected tile retaining portions 21a on which are hung wed ge shaped tile 22 to form a convex refractory arch portion depending into association with the fuel inlet. In association with these wedge shapedtile. one or more P parallel faced tile 24 are similarly suspended on each of the drop hangers, their lateral faces contacting side faces of juxtaposed tile, and their end faces forming continuations of the convex arch surface formed by the end faces of the wedge shaped tile. Above the tile 24 are disposed other Wedge shaped tile 22, also connected to the hangers 21.- At a location above the position occupied by these suspended tile, the drop hangers are provided with rearwardlyextending shelves 211), which are spaced apart from the terminals of the tile retaining members 21a so as to afford clearance for the mounting and dismounting of tile on the latter. These shelves form supporting platforms for brick 23 laid thereon to form a front curtain wall, or a connecting wall between the drop arch and the top arch. In the form illustrated this connecting wall is relatively low, but in many instances it will be of considerable height, and consequently of very considerable weight. The provision of the shelves 216, in addition to permitting I the removal and replacement of tile below this wall, Without requiring dismantling of any part of the latter, relieves the suspended tile from the weight of the wall which otherwise would be imposed upon them. Moreover, this construction relieves the wall portion of possible effects arising from differences of expansion and contraction in the drop arch androof arch, with the result that the likelihood of opening the joint between that wall and the top arch is very materially decreased. This is a factor of great importance, when it is observed that appreciable expansion is likely to occur in the arch portion which is over the fire, while the depending ignition arch, which is nearer the fuel inlet-is not likely to be subject to an equally high temperature. The space between the topmost suspended tile and the lowermost tile carried on the shelf 21?) is filled by filler bricks resting on the suspended tile.

It will be observed that the ignition arch constructed as. above described has a relatively narrow end immediately over the fuel inlet, from which portion the arch surface rises quite quickly and steeply toward the top arch. This construction of the wall gives the desired protection for the stoker front and the front suspension beam 14, while accommodating maximum reflection of radiant heat from the top arch onto the green fuel at the fuel inlet.

It is to beobserved that the construct on of the top arch affords an assembly in which the individual tile are susceptible of limited relative movement. Tile supporting members 19 are suspended so that the individual courses. carried by them respectively, or the entire refractory arch, may be swun latorally, longitudinally or vertically. This is one of the advantageous features of suspended arches of this type, as it enables the arch to accommodate expansion and contraction in its component parts without injurious strain upon either them or the associated parts of the furnace construction, such as the side Walls.. At the rearward end of the flat arch I prefer to employ fan end or mu, ate arch nose construction of the general sort illustrated in and claimed in my U. S. Patent 1,544,580 above specified, or of the sort is filled with filler brick 29, removal of which permits removal and replacement of the tile 26 without requirin dismantling of any of .the apron wall. Li ewise, the construction is usually associated a curtain or apron wall which forms a closure between the arch and the forward portion of the boiler setting. When this curtain wall is of comparatively small vertical extent it may be carried on-the rear end of the suspended arch. In instances in which the apron wall is high and heavy,

the imposition of its weight upon the rear end of the suspended arch may impose. too much weight upon the arch angers, and tend to rotate the arch on a horizontal axis, with the resulting tendency of the forward endv of the arch to separate from the drop arch, or open the joint at the forward margin of the top arch. As a means for obviating these tendencies, and for removing undesirable restricting or opposing limitations to the self-adjusting movements of the arch, I provide a plurality of wall brackets 27 a form of which is illustrated in detail in Fig. 3. Preferably each bracket has a shelf ortion 27 a at the rearward end of a barike body portion strengthened by marginal flanges 27?; and equipped with a hook-like portion 270 spaced from its forward extrempermits the individual removal and replacement of the wall brackets 27, or of any por-- tion of the curtain wall, without requiring,

dismantlin 'of any of the parts in the suspended arc Inasmuch as the wall brackets 27 are'independent of the tile supports, the number of brackets-emplifyed is determined entirely by the requirements imposed by the weight of the apron wall, so that the amount ndently of the suspended arch. 'The space tween the tile 26 arid the wall brackets 27 of metal may be reduced to a minimum when.

the-wall is light or the number of brackets increased in excess of the number of tile j supports 19, if the weight of the apron wall demandsit.

The construction, of course, is susceptible of use in various locations, as in the back arch illustrated at the right hand end of Fig. 1

whereinthe tile supports 19' carry the susi e rear end of the stoker pended arch over t or grate, and the wall brackets sup'port a part of the back wall or bridge wall 30.

An advantage of the construction resides in the fact that the entire wall above the flue end of the suspended arch may be supported-- entirely from a structural member such as the beam 15, while affording that member complete. protection from the furnace by means of. he portion of the wall carried on the brackets 27, and permitting the supporting structural member to be spaced away from.

the/refractories to afford the circulation of air necessary to prevent overheating of the metallic member. It is of particular. importance in wide furnaces, in which the support of the apron or curtain wall in associationi with high set boilers presents a diflicultproblem when it is desired to employ suspended ity and adapted to hook over thelower flange of the span beam 15. The bracket also may be provided with a retaining member 27d adapted to engage the span beam to prevent displacement of the hook portion 270 from its flange. When positioned on the span beam, the bracket forms a cantilever fulcrumed on the hook portion 27 c and with the part forward thereof contacting the bottom of the beam to hold the rearward portion against downward rotation, As illustrated in Fig. 2, these wall brackets are "positioned on the span beam in collateral disposal andat any desired intervals. Their position thus-may. be accommodated to the adjacent hangers '18 and; to other elements of the structure. Their rearward ends project over the tile supported on the end brackets 25 and afford supports for the brick forming the apron wall 28, which thus is supported indealso given a rearwardly tiltin moment.

arches. The stay member 16 performs an important function in the supporting of the arch structure, aside from its support of the beams 17. It will be observed that by virture of the fact that a considerable proportion of the weight of the curtain wall 28 is carried on the laterally projecting shelf members 27, that the beam 15 is loaded eccentrically of its longitudinal axis, so that a moment is imparted to it which has the tendency of tilting it rearwardly. The same is'in a measure true of the beams 14, which, due to the fact that it is eccentrically loaded by the ignition arch members and by the apron wall 23 which is carried on the rearwardly'proj'ecting brackets 21b, is

To counteract this loading on bot the beams 14 and 15 the sta beam-16 is rigidly connected to them in suc relationship that they cannot tilt under the weight of their eccentric loads, said beams 14 and 15 exercising reciprocal bracing eifects upon each other through the instrumentality of the stay beam16. By virtue of the construction, therefore, the ignition arch and the curtain wall 28 are maintalned in fixed relation with respect to each other, while the top arch is maintained flexibly suspended in the desired relation to them to form an intervening closure. The construction is of particular utility b virtue of the fact that while'it provides this stability of support for the refractories, the metallic supporting members are arranged in such relation to the refractories that they are afforded ample ventilation, and thereby protected against destructive overheating.

What I claim is:

1. In a travelling grate stoker furnace, an ignition arch comprising frame members, wedge shaped refractories connected at their narrower ends thereto and spaced apart vertically, and otherrefractories having parallel sides disposed between the wedge shaped re= fractories and cooperating therewith to form a wall sloping inwardly and upwardly from the fuel inlet.

2. In a furnace, an arch structure com rising frame members, wedge shaped re actories connected thereto at their narrower ends and spaced apart vertically, and parallel sided refractories connected to the frame members and filling the space between the wedge shaped refractories and cooperating therewith to form a refractory wall extending inwardly and upwardly in the furnace chamber.

3. In chain grate furnace construction, frame members, wedge shaped refractories connected thereto at their narrower ends and spaced apart vertically, and other refractories having parallel sides interposed between the wedge shapedrefractories and connected to the frame members, the outer ends of the wed sha ed and other refractories forming a wa lsu ace sloping inwardly and upwardly from. the fuel inlet.

4. In a chain grate furnace,the combination with a top arch, of frame members arranged between the same and the fuel inlet, wedge shaped refractories connected at their narrower ends to said frame and spaced apart vertically, and other refractories having parallel sides inter ed between the vertically spaced wedge s aped refractories and connected to the frame, the outer ends of the wedge shaped and other refractories forming .a steeply inclined wall surface sloping inwardly and upwardly toward the top arch from the fuel'inlet. p

5. In a grate fired furnace an ignition arch construction comprisin in combination a frame, wedge shaped re ractories and parailel sided refractories suspended therefrom with their end surfaces merging to form a wall surface sloping sharply upwardly from the grate.

6. In a grate fired furnace, an arch construction comprising wedge shaped refracportion of t tories, parallel sided refractories interposed betwen the wedge shaped refractories, and securing means cooperating with the outer ends of said refractories to hold their inner ends in alignment to form a heat reflecting surface sloping steeply upwardly from the grate.

7 In furnace construction, the combination with a top arch, of drop hangers depending therefrom above the fuel inlet, wedge sha ed tile suspended from said drop hangers to orm a radial arch portion rising toward the top arch, and parallel sided tile sus ended on said drop hangers to form a straig t continuation from the radial arch portion, the inner end surfaces of the wedge shaped and parallel sided tile cooperating to form a regular and uninterrupted refractory surface sloping upwardly from the fuel inlet toward the top arch.

8. In furnace constructionincluding a top arch, a beam arranged adjacent the margin of the top arch, drop hangers suspended on said beam and depending below the top arch, tile suspended on said drop hangers to form a depending arch portion, shelves supported on said drop hangers, and refractories supported onsaid shelves intermediate the depending arch portion and the top arch.

9.- In furnace construction including a top arch, a series of drop hangers supported adjacent a margin of the top arch, tile suspended on said drop hangers to form a depending arch portion below the top arch, shelves supported on said drop hangers, and refractories supported on said shelves to form a wall portion conjoining the top arch and the de ending arch portion. I

10. n furnace construction, including a top arch, drop hangers supported adjacent the margin thereof, t1le suspended on the drop hangers in association to form a depending arch portion, shelves supported on said drop hangers above the tile, and refractories supported on said shelves to form a wall ortion intermediate the depending arch ortion and the top arch, tile being removab e from the drop hangers without requiring displacement of said refractories.

11. In furnace construction, the combination of a supporting beam dis osed above a.

ported thereon and extending laterally thereof, a wall ortion carried on said shelf, and a stay mem er secured to the beam to afford a counterpoise to the weight of the shelf and supported wall portion.

12. In furnace construction, the combination of a beam extending transversely of the furnace, a wall portion carried on said beam and: loading same eccentrically and a stay member secured to the beam and extending forwardly over the furnace structure and ads. tedto resist the tilting moment imparted to e beam by the weight of the wall portion.

e furnace, a shel member sup-' 13. In furnace construction, the combination of a beam extending above the furnace, a shelf member supported thereon and ex tended laterally therefrom, a wall portion supported by said shelf member, a stay member secured to the beam and extending oppositely to the shelf member, and an arch suspended from said stay member in association with the wall portion, whereby the weight of the arch and the wall portion are transmitted to the beam as opposing moments. 1

14. In furnace construction, the combina tion of a beam extending transversely of the furnace, a shelf member supported on and extending laterally from said beam, a wall portion supported on the shelf member, a stay member extending longitudinally ofthe furnace and connected to the beam, whereby to resist the tilting moment imparted by the weight of the wall portion, and an arch portion sustained by said stay member in association with said-wall portion.

15. In furnace construction, the combination of beams extending in substantially parallel relationship, a shelf member supported on and extending laterally from a beam, a wall portion carried on said shelf member, and a stay member rigidly connected with the beams, whereby they cooperate to sustain the wall portion.

16. In furnace constructlon, the combina tion of beams supported at forward and rearward portions of the furnace, a shelf su ported on and extending laterally from a eam, a wall portion carried on said shelf, a stay member connecting the beams in relationship to resist the tilting moment imparted by the weight of the wall, and arch portions sustained by said beams and stay member in association with said wall portion. 17. In furnace construction, in combination, collaterally arranged hangers, wedgeshaped refractories supported at the lower endsthereof, and parallel-sided refractories anchored to the hangers with their upper and lower, parallel faces in sloping position and parallel to upper faces of the wedgeshaped refractories and with the inner faces of said wedge-shaped and parallel-sided refractories cooperating to form an archsurface sloping upwardly from the lower end of the structure.

18. In furnace construction, tion, portion of the furnace chamber and constituting an eccentrically loaded support for a portion of the refractory structure of the 1 furnace, means supporting said beam at itsends, a stay beam connected to said transverse beam and extending therefrom over'a portion of the furnace chamber, and a roof arch suspended below the sta beam and having a portion of its we1g t susta ned thereby, whereby said stay beam and weight in combinaa transverse beam across a rearward of the arch portion are adapted to oppose the turning moment exerted on the transverse beam by its eccentric load.

19. In a furnace installation, in combination, a transverse beam disposed over a forward portion of the furnace, a transverse beam spanning a rearward portion of the furnace chamber, a stay beam extending longitudinally over a portion of the furnace and connecting said transverse beams, a wall structure supported by the rearward transverse beam, transversely extending members supported in part by the stay beam, an arch nose structure supported from the rearward transverse beam, hangers depending from the transverse members, and a roof arch suspended by saidhangers below the stay beam and transverse members and 'in conjoining relationship with the arch nose.-

In testimony whereof I have hereunto signed my name. LOUIS H. HOSBEIN.

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