US1767406A - Furnace-wall construction - Google Patents

Description

I Patented June 24, 1930 UNITED STATES PATENT OFFICE FRANK I. SHEAHAN, OF CHICAGO, ILLINOIS, ASSIGNOR. TO M. H.- D'ETRICK COMPANY,

OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS FURNACE-WALL CONSTRUCTION Application filed J'une 16, 1928. Serial No. 286,049.

This invention relates to the construction of furnace or combustion chamber walls of the sort whereiri fire brick or refractories are utilized to form the heat-resistant wall portion. It pertains particularly to an improved construction and structural elements for forming expansion joints in such walls which are sectionally supported.

Types of furnace walls are "now known in which the heat-resistant or heat-confining wall of the furnace is made up of refractories, such as fire brick, so supported as to form conjoining sections arranged one above another, the respective sections being supported independently of those vbelow them,

with provision for accommodation of expansion of respective sections. Such constructions are designed particularly to avoid the heavy loading of lower portions of the 0 refractory Wall structure by the weight of super-imposed portions, and to avoid the subjection of the refractories to high com-. pression such as might result from thermal expansion of the refractories when highly heated. The ultimate object, of"

to increase the term of serviceability of the refractories by relieving them of forces such as result from the conditions just inentioned, which forces would contribute to distortion of the refractories and the walls'and procourse, is

mote disintegration of the refractories incident to heating and cooling.

The present invention is concerned primarily with the provision of structural features'for forming the expansion joints in such walls, and-its general object is the provision of a construction and structural elements for forming the same which will contribute to the durability of the refractories involved in the expansion joint censtruction, acgommoda'tethe necessary expansion while maintaining closed joints between juxtaposed sections, and maintain'the cooperating joint refractories in the desired relationship while at the same time permitting removal and replacement of refractories at the joint in the makin of reairs without'involving the remova of re-' ractories from the superjacent sectioni 5 More specifically, one of the objects of the .struction showing a part interior elevation invention is the provision of an improved olnt construction and elements for formlng .it which will minimize the surface exposure of respective refractories to the wearing efiects, such as sla ging, which occur within the furnace cham er.

Another specific object of the invention is the provision'of a joint construction and elements for forming same which will mize the liability of the refractories to spalling.

Other and further objects of the invention will be pointed out or indicated hereinafter, or will appear to one sln'lled in the art upon an understanding of. the invention or its employment in practice.

In the drawing forming a part of this specification I illustrate certain forms of a furnace wall construction and structural elements in which my invention may be em- 70 bodied, but it is to be understood that these are presented for purpose of illustration as the invention as defined .in the appended claims is susceptiblepf embodiment in forms and constructions differing in particulars from those here shown and hereinafter de scribed.

In said drawing v Fig. 1 is a detail of furnace wall conof one wall and a part sectional elevation of an adjoining wall, the section being taken on a line approximating line 'AA;

Fig. '2 is a detail in the nature of a part sectional elevation corresponding to the sectional part of. Fig. 1 but showing the relationship of refractories at the joint consequent upon thermal expansion of the wall refractories;

Fig. 3 is a perspective view of one of the .joint refractories;

Fig. 4 is a perspective view of another of the j oint refractories;

Fig. 5 is a face view of one of the wall refractories illustrating the relationship thereto of'certain joint refractories, and

Fig. 6. is a Perspective view of an anchor-" ing element or joint-refractories.

The nature of the invention will be most quickly ascertained by consideration of the examples shown in the drawing. Let it be understood that the furnace wall construction here shown is generally of the type illustrated and described in U. S. Patent No. 1,747,822, to Raymond D. Foltz, assigned to M. H. Detrick Company: With such understanding, it will be recognized that the members designated 10 represent wall hangers which have vertically extending bar-like body portions with outwardly extending arms 10 and 10 at their upper and lower ends respectively, and lateral flanges 10 along their innermargins above inwardly extendingshelves 10 By means of the arms 10 and 1O the hangers are supported on suitable frame members, as disclosed in the application and the patent mentioned above,-

so that the hangers may be-arranged collaterall in series, with the series one above anot er, and the body portions of the hangers extending in a generally vertical direction. The respective horizontally running series of hangers support wall sections arranged one above another, the respective sections being made up each of a plurality of refractories so associated as to present a regular interior wall surface, which constitutes the firesurface of the chamber wall. These refractories, in the construction herein illustrated, are of three forms, same comprising the overlying joint refractories 11,

the underlying joint refractories 12 and flat refractories 14. The wall sections are composed for the most part of the flat refractories 14, a course of the overlying joint refractories 11 being employed at the bottom of each section, and a course of the underlying joint refractories 12 being employed at the top ofeach section. The fiat refractories 14 and joint refractories 11 may be of the same general face contour, such as that shown in Fig. 5, having parallel lateral sides arranged at right angles to their inner ends and with T-shaped slots S formed at the middle of their outer ends, which slots are of such size as to accommodate the flanges 10 and por-. tions of the web of the hangers so that said flat refractories may be slipped on tto said flanges at the upper ends thereof and thus afforded an anchoring engagement with the associated hangers. Whlle each of the flat refractories 14 is of uniform thickness throughout, the joint refractories 11 are formed with' an offset portion 11 so that they are thinner at the slotted end than at the opposite end, their opposite faces, however, being parallel. The'ofiset 11 is arranged at such a distance from the slot S as to accommodate the shelf 10 of the hanger, so thatwhen one of these refractories is positioned on the hanger as above described, it ma be slid down on the flanges 10 until the thinner portion comes to rest on the shelf 10, whereat the offset portion 11* will depend down 'across the inner margin of the shelf. The thinner portion may be recessed as illustrated at 11* to'accommodate the shelf. A course of the refractories -11 being thus disposed on the their width may be'some fractional part of the width of the refractories 14, such as onehalf, one-third or one-fourth. They are most conveniently made of approximately the same length as the refractories l1 and 14, with parallel opposite side faces meeting the inner end face at a perpendicular and with the bottom face perpendicular to the side and inner end faces. The top face is formed-with an offset 12*- which is spaced from the inner end by a distance slightly greater than the corresponding spacing of the offset 11 of the overlying joint refractories 11. At a distance from the inner end corresponding to the spacing of the slots S in the refractories 11 and-14,'the refractories 12 are provided with a transverse groove 12 in the lower face, and the outer end preferably is beveled ofl somewhat in the fashion shown. The ad jacent horizontal series of hangers are disposed in such relationship that the vertical distance between their shelves is such as to accommodate the co 'r e of refractories 11 and the desired number of courses of refractories 14 and-leave a clearance between the top surface of the uppermost refractories 14 in engagement with the hangers of the lower .series and the lower surface of the superjacent refractories 11, such as to accommodate insertion of the refractories 12 therebetween from the inner side of the wall. This vertical clearance, therefore, is slightly in excess of the thickness of the refractories 12 between their bottom faces and the top face of the ofisets 12. The refractories 12 are inserted in the position illustrated in Fig. 1, a

in which there is a slight horizontal clearance between the offsets 12 and 11 and the space between the lower faces of the thicke'ned portions of refractories 11 and the upper face of the refractories 12 is filled with a packing of compressible refractory mate.

oifset 12 is free to move upwardly across the vertical face of the offset 11", as to a position illustrated in Fig. 2, thus giving a sliding contact between the juxtaposed faces ofthese offsets which maintains a closed joint of tortuous form at the outer side of the packing 15. Thus the juxtaposed sections are given the desired freedom of movement at the expansion joint to accommodate expansion without subjecting each other to undesirabl compression forces, and at the same time the'joint is maintained tight against leakage of air and flame.

As a means for anchoring the refractories 12 against displacement either inwardly or outwardly, anchoring members 16 are employed. These anchoring members are small iron castings having a seating lug 16? adapted to fit in the slot of a refractory 14 and a holding portion 16 adapted to rest upon and-extend over a portion bf the upper face of the refractory 14 in parallel relationship to the slot. The holding portion 16 is of size and form to be received in the grooves 12 of refractories 12, and preferably is of such length as to engage a plurality of such refractories resting on the refractories 14. By virtue of such engagement the refractories 12' thus engaged are heldagainst displacement either inwardly or outwardly of the wall, so that their inner end faces are held in alignment with the faces of the other wall refractories.

It is not desirable that all the refractories 12 be thus anchored by the members 16, as such would preclude the removal of the refractories from between ,the sections in making repairs or replacements. Consequently, the

length of the holding members 16'? is such that there will be space for insertion of a refractory 12 between those in engagement with adjacent anchoring members. Such an arrangement is illustrated in Fig. 5, wherein the positions of four of the refractories 12 are shown in dotted lines in relationship to an underlying refractory 14. It will be observed that the two intervening refractories 12 will be enga ed by the anchoring member 16, whereas t e-two outer refractories 12 will be free from the anchoring members. These free refractories are held in position by their frictional contact with the refractories on which they rest and the anchored refractories 12 at opposite sides of them, and their inward displacement by expansion is prevented by their engagement behind the ofisets 11 of overlying joint refractories, as illustrated in Fig. 2. In the original building of the wall, it is built from the bottom up, a lower section being completed with the refractories 12 in place before the superjacent section is started. For the purpose of replacing refractories in a limited area of the wall after the furnace has been in operation, however, it may be desirable to remove refractories ina lower section without disturbing a superjacent section. In making such a replacement, one or more of the free refractories 12 may be knocked out, whereupon adjacent anchored refractories 12 may be slid laterally into the space thus afforded until clear of the end of the anchoring member, and then withdrawn from the wall. By removal of a sufficient number of the joint refractories 12 in this fashion, vertical space is afforded for removal and replacement of underlying refractories 14 and 111 After replacement of those refractories, the anchoring-members 16 may be placed on the uppermostrefractories 14 in the replaced portion, and the joint refractories 12 inserted into the wall between the anchoring members and slid laterally into engagement with them, the intervening spaces between the anchored refractories 12 being closed by insertion of such refractories in the spaces between the anchoring members. Thus, it will be observed, replacements may be made with facility in any section without involving removal of refractories from a superjacent section, and at the same time the various refractories'are so anchored and retained in the wall as to prevent their displacement by expansion and pulsations while the furnace is in operation. It will be understood, of course, that the, fit of the various refractories on the flanges 10 and on the anchor ing members 16 is sufliciently free to allow the refractories limited latitude of individual movement, so that they may accommodate themselves to .pressures without fracturing the portions inengagement with said parts.

By virtue of the accommodation for ex-f pansion afforded by the construction, and the avoidance of heavy loading of any of the refractories, and their limited freedom of individual movement and their form and relationship in the assembly," the conditions most conducive to spalling are avoided, yet the wall is. afforded secure support and is maintained definitely in align ment. Rapid wearing away of the refractories 11 and 14 .byslagging is avoided by the cooling efiect of the hangers, which, it will be observed, have substantial areas embedded in the refractories and substantial areas exposed to air circulation outside the wall, whereby they exercise a certain. heatdifiusing efiect. The refractories 12 are not afforded this cooling effect to the extent that the others are, as they do not have direct engagement with the hangers. It will be observed, however, that the areas of these tories, practically equalizes the temperature of the refractories 12 with the others; with the result they are not subject to wear by may be given a harder burn in manufacture,

and their liability to disintegration under conditions of furnace operation. thereby reduced. The joint refractories 11, while having the greatest area exposed to the furnace fire, have at the same time the greatest area of contact with the heat-diffusing hangers, so that the temperature of their exposed surfaces is practically equalized with that of the adjacent refractories. Consequently, byvirtue of the construction and form of various structural elements, the tendency to more rapid wear on disintegration of refractories at the expansion joint which has been observed in some constructions heretofore employed is effectively decreased.

A particular advantage in the present invention resides in the fact that the structural elements such as the refractories 11 and 12, standardized as to form and dimensions, may be employed quite generally .in walls of different sizes and furnaces of different designs, with the result that original and maintenance costs may be kept down and repairs and replacements simplified and facilitated. 7

What I claim is:

. 1. A furnace wall structure comprising, in combination, refractories arranged to form Wall sections one above another, means for supporting respective sections independently, the refractories at the meeting margins of sections comprise overlying joint refractories and underlying joint refractories spaced vertically to afford an expan sion joint, the underlying joint refractories having their outer ends of greater area than their inner ends so as to have greater surface exposure at the outer side of the wall than at the inner side thereof, saidunderlying refractories being withdrawable horizontally from the wall while the overlying joint refractories are in place. 2. furnace wall structure as specified in claim 1 and wherein the overlying and underlying joint refractories have portions arranged to overlap in substantially perpendicular relationship to the expansion joint. 3. furnace wall structure as specified in claim 1 and wherein the overlying and underlying joint refractories have offset 1P0?- $10113 arrangeddzo overlap upon thermal expansion of the -wall sections, to close the expansion joint.

4. A furnace wall structure as specified in claim 1 and including means for anchoring res ective overlying and underlying oint re actories in the wall to hold their mner end faces in the same plane. s

5. furnace wall structure comprising,

in combination, an underlying joint refractor an overlying joint refractory suppodted independently of the underlying joint refractory and above the same with an intervening space to accommodate relative vertical expansion of the refractories, means for anchoring the overlying refractories .in position, said underlying refractpry having anrupstanding. projection adjacent its outer end, the overlying refractory having a depending portion adjacent its inner end, said portions arranged to over-' lap in an approximately vertical plane, the overlying joint refractorybeing removable horizontally inwardly from below the overlying joint refractory while they latter is anchored in place.

6. A furnace wall prising correlated overlying and underlying joint refractories, the respective underlying joint refractories being larger at one end than at the other end, having parallel top and bottom face portions and formed with a transverse groove near one end of the bottom face portion and an upstandingvoflset portion on its upper side above saidgroove, the respective overlying joint refractories having parallel top and bottom faces and a T-shaped slot extending throu h one end perpendicular to said faces a an offset portion on its lower side of a ength corresponding to the distance between the olfset portion and the smaller end'of the underlying joint refractories.

7. Joint elements for furnace walls comprising correlated overlying and underlying joint refractories which are thicker at one end that at the other and each having one plane end, respective overlying and un-' derlying joint refractories having offset portions adapted to overlap in a plane approximately parallel to their plane, ends, respective underlying joint refractories having parallel top and bottom faces and a transverse groove in the lower side near one end, the respective overlying refractories having a T-shaped slot extending through one end in a direction approximately parallel with the plane end.

8. As an article of manufacture, a poly hedral furnace wall refractory having parallel side faces and o .posite end faces and a bottom face perpeli icular to the side faces and one of the end faces, the bottom side being provided with a transverse groove adjacent one end and the upper side of the refractory beinig formed with an upstanding transverse y extending offset portion above the groove, the end of the refractory which is adjacent the groove having greater surface areathan the other end.

9. As an article of manufacture, a polyhedral furnace wall refractory having parallel joint structure comside faces, a bottom face perpendicular thereto and an end face perpendicular to I slot extending said bottom and side faces and a. top face ortion parallel to the bottom face, said reractory being provided on its upper side with a transversely extending offset portion extending upwardly from said top face portion and in its bottom with a transverse groove extending perpendicularly to the'side faces and disposed near the end of the refractory opposite said end face.

10. In furnace wall structure,cin combina tion, flat refractories each having its broader faces parallel and extending per endicularly to a plane end face and a -shaped through the end opposite said end face, an joint refractories each of less width than the flat refractories but of approximately the same length as the latter, each of said joint refractories having its side faces parallel and a bottom face perpendicular to the side faces and an end face perpendicular to the bottom face, said joint refractories each being provided with a transverse groove in its bottom side extending parallel to said end face and-s aced therefrom by a distance correspondin to the perpendicular distance between t e plane end face and the head of the T-shaped slot, each of said joint refractories having an upstanding offset portion on'its top side over said groove.

11. Furnace wall structure as specified in claim 10 and wherein the width of" the respective joint refractories is a fraction of the width of one of the flat refractories.

12". A furnace wall structure as specified in claim 1 and including shelf portions for supporting the wall sections, the overlying joint refractories having portions depending across the inner margins of said shelf portions.

In testimony whereof I have hereunto subscribed my name.

FRANK I. SHEAHANI

Images