US1870568A - Furnace construction - Google Patents

Description

Aug. 9, 1932.

L. H.' HOSBEIN FURNACECONSTRUCTION Filed April 13, 1929 4 Sheets-Sheet 1 frwevz/m f/f/osbezn, MM 5 Aug. 9, 1932. L. H. HOSBEIN FURNACE CONSTRUCTI 0N Filed April 13. 1929 4 Sheets-Sheet 9, 1932" H. HOSBEIN FURNACE CONSTRUCTION Filed April 13, 1929 4 Sheets-Sheet 3 fizz/62275?- fflfoabean,

Aug. 9, 1932.

L. H. HOSBEIN 1,870,568

FURNACE CONSTRUCTION Filed April 13, 1929 4 Sheets-Sheet 4 L [ZZZ/8W: 210w Hhaabarz,

g @haccenaa (W5 Patented Aug. 9, 1932 UNITED STATES PATENT OFFICE LOUIS H. HOSBEIN, OF WINNETKA, ILLINOIS, ASSIGNOR TO I. H. IJE'IBICK COMPANY,

OF CHICAGO, ILLINOIS,

A CORPORATION OF ILLINOIS FURNACE CONSTRUCTION Application filed April 13, 1929. Serial 110. 354,724.

This invention relates to the construction of furnaces wherein the furnace roof is formed of refractories, such as of ceramic material. It pertains articularly to an improved construction or furnace roofs or arches of the suspended type.

A general object of the invention is the provision of a furnace roof construction of the suspended type, which will contribute u to the longevity or term of usefulness of the roof refractories and of the roof as a whole, facilitate replacement of the refractories in the roof structure, and be economical in both original cost and maintenance.

as Another object is the provision of roof con struction which is particularly qualified for the use of silica refractories, although not limited to such for its various advantages.

Another object is the provision of an 1111- w proved and advantageous form of tile or refractory particularly adapted for use as an element for furnace roof construction.

Another object is the provision of an improved furnace roof construction wherein w the refractories throughout may be of uniform size and design and the supporting members may be likewise standardized.

Yet another object is the provision of an improved form of hanger or supporting member for suspending refractories to form a furnace roof portion.

Other and further objects will be pointed out or indicated hereinafter or will be apparent to one skilled in the art or upon an understanding of the invention from the present disclosure or from employment of it in practice.

In the accompanying drawings forming part of this specification and in the following description of the same I disclose an example of furnace roof construction wherein the invention is embodied; but it is to be understood that this example is presented for purpose of illustration merely and is not to be accorded any interpretation having the effect of limiting the appended claims short of the true and most comprehensive scope of the invention in the art.

In the drawings,

Fig. 1 is a diagrammatic illustration of a.

portion of a furnace arch or roof such as may be employed in an open hearth furnace, the illustration being in the nature of a sectional elevation of part of the roof adjacent one of the end walls;

Fig. 2 is a detail in the nature of a part sectional elevation of a furnace roof portion, such as might be taken along the line 2-2 of Fig. 1;

Fig. 3 is a detail in the nature of a top view of a portion of such furnace roof structure;

Fig. 4 is a detail, on larger scale, in the nature of a top view of a pair of arch refractories and a portion of their supporting member;

Fig. 5 is an elevational view of the upper end of one of such refractories, illustrating the hanger pocket;

Fig. 6 is a diagram in the nature of a top view of a portion of a furnace roof structure such as shown in Fig. 3, and illustrating various steps in the operation of removing a section of the roof Fig. 7 is an illustration of associated pairs of roof refractories and their supportin means, one pair being shown in section and the other in elevation; and

Fig. 8 is a part elevational view of a modified form of tile supporting member.

I have ascertained that it is of particular advantage in furnace roofs which are subjected to trying conditions, such as extremely high temperatures, gas and flame erosion, extended periods of continuous operation, and intervals of varying temperature, to use refractories of such size and form as to afford the smallest practicable surface exposure in the fire chamber as circumstances permit. The reduction in size of the roof refractories involves a correlative increase in the number of them which have to be used to cover a given area, and involves complicated problems in the provision of means of support and forms of refractories which will give the roof structure the necessary stability and at the same time the requisite flexibility, permit of standardization of the various parts, facilitate assembly and repair of the structure, all within economical cost limits. These difliculties are increased in the provision of a construction wherein it is desired to employ silica refractories, on account of their range and rapidity of expansion, their low tensile strength at high temperatures, and thentendency to spall. The present invention is directed primarily, therefore, to a furnace roof structure and constituent elements thereof which will enable the use of refractories of small size without inyolving complication of the structure and costs disproportionate to the advantages gained.

The nature of the invention will be most quickly ascertained from a consideration of the form shown on the drawing now to be described by way of example. Fig. 1 is intended to represent a portion of a roof of an extensive furnace, as an open hearth furnace, the reference numeral 10 designating a wall, the reference numerals 11 designating fiat portions of the roof and the reference numeral 12 designating a sloping portion of the roof. The reference numeral 14 designates one of a series of roof supporting beams which are arranged above the roof and carried on columns, buck staves or other structural members outside the furnace, or, where feasible, on the furnace walls. These beams constitute the supports for the hangers which carry the roof refractories. These hangers comprise tile supports 15 and suspension rods 16. The tile. supports preferably are cast iron members having a body portion in the form of a web with lateral flanges 15 along its lower margin and tile engaging members 15" extending therefrom. At their lower sides they may be longer than the distance between the juxtaposed supporting beams 14, but have their webs somewhat shortened, as at 15 to a length somewhat shorter than the distance between the beams 14. The tile engaging members 15" are spaced at approximately equal intervals along the length of the tile supporting member and have transversely directed hook-like portions connected to the lower portion of the tile supporting member by flanged shanks, and preferably are cast integrally with the tile supporting member. The web of the tile supporting member is provided adjacent its ends with apertures 15 for reception of the suspension rods and with apertures 15 for accommodation of a lifting device, as hereinafter explained. The suspension rods 16 are hooked at their ends for engagement in the apertures 15 and with the rod keepers 17. These keepers are cast iron members formed with recesses 17 and overhanging lugs 17 for accommodation of any engagement with the lower flanges of the supporting beams 14. onto which they are slid at the ends of the beams, and hanger retaining portions 17.

Each of the tile supports 15 is adapted to carry. on its tile engaging members. a plurality of roof refractories 18 in such fashion that the refractories will hang vertically with their vertical faces in contact. In the embodiment illustrated each tile support carries ten refractories, two being supported on each of the tile engaging members. Each of these groups of refractories carried by a tile support may be regarded as a roof section. The supporting beams 14 are spaced apart in accordance with the length of these roof sections, and in order to maintain continuity of the roof closure formed by the roof sections, it is necessary that the ends of the sections underlie the beams. In order to afford the necessary accommodation for longitudinal expansion of the sections, the ends of adjacent sections are spaced apart to afford the expansion spaces 19. The refractories are of rectangular form with their opposite faces parallel. For convenience of identification I will refer to the face shown in Fig. 5 as the inner side or face, the face opposite it as the outer side or face. and the two at the right and left of it the lateral sides or faces. The major dimension, or length of the refractories, is that of the thickness of the refractory roof which they form. It is desirable to make their cross-sectional area as small as feasible. In the form illustrated their width is slightly more than one-third of their length and their thickness approximately one-fourth their length, and they are all alike in size and form. Each of these roof refractories is formed with a hook-receiving pocket 18 adjacent one end extending into the body of the tile from its inner side at a sufiicient distance from the proximate end to afford a supporting ligament 18 of substantial thickness bridging the hook-receiving pocket. The outer margin of this ligament is in-set somewhat from the inner face of the tile, preferably with an arcuate contour as shown in Fig. 4. to afford a hangeraccommodating notch. The ends of the ligament remain integral with the body material of the tile at the sides of the hook-receiving pocket. The width of the hook-receiving pocket 18 is such'as to accommodate a hook of one of the tile engaging members with a liberal clearance on each side thereof. and the width of the hanger notch 18 is such as to accommodate the shank of the tile engaging member with a similar clearance on each side thereof. The depths. into the tile. of the hook-receiving pocket and of the hanger notch are such that when a pair of the refractories is supported on the tile engaging member. their juxtaposed faces may re t in abutment. and there will be sufficient clearance for a limited play of the pair of refractories on the tile engaging member in horizontal directions without disengaging the ligaments 18* from the hooks. The underface of the ligament is preferably flat and parallel to the ends of the tile. so that there will be no change in the elevation of the tile incident to its shifting on the tile engaging member. Due to the excess width of the hook-receiving pockets, each tile has a. substantial latitude of movement on the tile engaging member in the longitudinal directions of the section, so that the tiles may adjust themselves to accommodate the expansion of one another without imposing additional pressures on the tile retaining members or cramping the tile portions therebetween. All the tiles of a section, accordingly, are able to accommodate themselves to expansion within the section, and the aggregate longitudinal expansion of the section is accommodated by the expansion spaces 19 between juxtaposed sections. As seen in F igs. 1 and 3, a number of the sections are hung side-by-side with their refractories in abutment, and at intervals an expansion space 20 is left between sections. Thus, the transverse expansion of the sections is accommodated in the same fashion as is their longitudinal expansion. These expansion spaces are closed at the top of the roof by refractories 21 which are laid on the upper ends of the roof refractories over the expansion joints.

The height of the supporting beams 14 above the level of the roof portions which they carry is sufiicient to permit a. roof section carried on a supporting member 15 to be lifted clear of the adjacent roof refractories and supporting members. This may be accomplished, as illustrated in dotted lines in Fig. 2, by engaging the hooks of a lifting p cable or chain L in the apertures 15 of the selected supporting member, and elevating the same to draw the refractories carried on said member upwardly from the roof. Due to the necessary length of the roof section, it cannot be elevated straight up between the beams 14, as its ends extend for a distance under the beams. Consequently, it will first be elevated to approximately the position illustrated in dotted lines in Fig. 2, where it is clear of the adjacent roof refractories and supporting members. Then, the suspension rods having been removed, it will be slightly p rotated so that the web of the supporting member will clear the keepers 17, and there'- .IPOII the section may be moved longitudinally to a position approximating that designated by the reference character II in Fig. 6, the shortened end portion of the supporting member accommodating the beam flange at one end of the section so that the, other end of the section may be swung out from under the opposite beam and to a position where it will clear the suspension rod 16 of the adjacent section. Then the elevated section may be further rotated and moved longitudinally to a position approximating that designated III in Fig. 6, wherein its outward end will clear the adjacent suspension rod 16". Then it may be rotated to the position designated IV in Fig. 6, in which it is completely clear of all suspension rods, supporting beams and other portions of the roof, so that it may be elevated completely above the beams 14 if desired, or may be transported longitudinally between the beams to a position where its refractories may be removed and new refractories replaced on the tile engaging members. Then the section may be restored to its position in the roof by a series of operations converse to those just explained, the suspension rods 16 being finally engaged with the supporting member and the appropriate keepers to support the section in place. Thus, any roof section may be removed and replaced at any time, even while the furnace is in operation, the hole left upon removal of the section being closed during the interval with a temporary refractory cover.

The construction lends itself advantageously to the forming of slopin roof portions, such as illustrated for example at 12 in Fi 1. As pointed out above, the invention ren ers it possible to use refractories of small cross section. This is of additional advantage in such sloping roof portions because of the fact that the offsetting of small roof refractories at their lower ends, as shown in Fig. 1, involves only a comparatively small increase in the proportion of a tile exposed to the furnace fire, in order to obtain a given rise in the roof over a given horizontal distance. The rapidity with which refractories are worn out or destroyed in normal use deends to a large measure on the proportion of their surface area which is exposed to the furnace fire and combustion gases, and consequently the reduction of that proportion, which is rendered possible by the present invention, is of very substantial importance in maintenance and operating costs, this holding true as to both slo ing and fiat portions of the roof. The gra 'ent slope of the roof in the example shown in Fig. 1 is obtained by using suspension rods of appropriate lengths and tile supporting members wherein the tile engaging hooks on opposite sides of the suporting members are offset verticall as illustrated in Fi 8. Thus, the row 0 refractories supporte at one side of the supporting member will be maintained ata slightly higher elevation than the row on the opposite side, while the vertical ofi'set as between refractories carried on juxtaposed supporting members is obtained by suspending one at an appropriate higher elevation than the other.

It will be observed that the roof refrac tories have portions which are of uniform thickness from end to end of the tile. This is of distinct advantage in manufacture as it obviates the necessity of special handling and supporting of the tiles in the kiln and also lessens the possibility of cracks forming adjacent the hook-receiving pockets incident to the drying and burning of the tile. It

will be observed that the hook-receiving pockets extend for a substantial distance past the middle line of the tile, this to permit the use of hook ortions on the tile engaging members of en icient length to support the tile without dependence on the abutting tile or other tile supporting members. This independent support of each tile permits removal and replacement of any section as a unit, as above described, without involving displacement of any other portion of the roof structure. A distinct advantage of the construction resides in the fact that a relatively large number of tile are supported by a relatively small number of suspension rods, it requiring only two of the suspension rods 16 to support ten of the roof tiles in the construction illustrated. The flanges 15 on the tile supporting members function not only as strengthening elements but also as heat diffusing members, and due to the extcnsive area of the tile supporting members which is exposed to cooling air, heat is carried away from the tile engaging members with suflicient rapidity to prevent their destructive overheating. The ample clearance afforded between the shanks of the tile engaging members and the margins of the ligaments 18 allows free circulation of air from the tile-receiving pockets. and the depth of the pockets is sufficient to allow clearance between their bottom faces and the lower ends of the tile engaging members, as seen in Fig. 7, so that the tile engaging members are entirely surrounded by air space excepting where they contact the ligaments 18".

In the embodiment illustrated the expansion spaces 19 and 20 are shown as of considerable width. It will be understood that the allowance made for these expansion spaces will be such that they will be closed upon expansion of the roof refractories, so that when the roof is at the operating temperature the originally spaced refractories will be in lateral abutment, thus forming a tight roof. As pointed out above. expansion of the refractories in the longitudinal direction of the section is accommodated freely bv the elongated form of the pockets in that direction. this permitting the individual refractories to adjust themselves on the tile engaging members without subjecting either the latter or the tile ligaments and tile portions at the sides of the pockets to possibly injurious pressures. These features are of particular importance when silica tile are used. as is customary in most steel and melting furnaces. because of their relatively large coeiiicicnt of expansion and relatively low tensile strength at high temperatures.

I claim:

1. In furnace roof construction, in combination, beams disposed above the furnace chamber in spaced relationship, tile supports suspended from the beams, a lurality of courses of refractories en aged with each tile support to form a mo section with the terminal refractories extending under the beams from which the section is supported, said sections arranged in association to form a refractory top closure for the furnace chamber, and the respective tile supports with their supported refractories being withdrawable upwardly to clear the roof and movable rotatably above the roof to clear the beams.

2. A roof construction for a furnace chamber comprising, in combination, beams arranged in spaced relationship above the furnace chamber, tile supports, suspension members demountably connecting respective ends of each tile su port to respective beams, a plurality of refractories suspended on each tile support in association to form a roof, section of a length approximately equal to the center-to-center spacing of its supporting beams, said roof sections associated to form a roof portion for the furnace chamber with the terminal refractories of the respective sections extending under their supporting beams being spaced above the roof to permit the respective tile supports and their roof sections to be moved upwardly and rotatably to clear the roof and beams.

3. A roof construction for a furnace chamber comprising, in combination, beams ar ranged collaterally above the furnace chamber, tile supports suspended from the beams and having depending tile engaging members, a plurality of refractories suspended on the tile engaging members of each tile sup port in association to form a roof section and each removable and replaceable independently of the others, the roof sections being associated to form a refractory roof for the furnace chamber and being individually withdrawable upwardly therefrom to a position above the associated tile supports and below the beams.

4:. A roof construction for a furnace chamber comprising, in combination. a plurality of tile supports, means for suspending said supports above the furnace chamber, a plurality of tile engaging members depending from each tile support, and a plurality of refractories suspended in parallel courses on each of the tile supports and associated to form a roof section movable independently of theother sections.

5. In furnace roof construction, in combination, a bar-like tile support, means for suspending the same in approximately horizontal position, a plurality of tile engaging members depending from said tile support and directed transversely thereof, and a plurality of refractories supported on said tile engaging members and associated in parallel courses to form a roof section.

6. In furnace roof construction, in combination, a tile support, suspension means permitting upward movement of the same, a plurality of tile engaging members carried on the tile support in spaced relationship, and a plurality of refractories suspended on the tile engaging members in parallel collateral courses and shiftable bodily thereon longitudinally of the courses.

7. In furnace roof construction, in combination, a bar-like tile support having a plurality of laterally directed tile engaging members thereon in alignment and spaced relationship, means for movably suspending said tile support with said tile engaging members in substantially horizontal position, refractories suspended on the tile enga ing members and formed with recesses and ooh-receiving pockets accommodating the same and permitting removal of the refractories laterally from the tile support and bodily shifting movement of the refractories on the tile engaging members longitudinally of the tile support.

8. In furnace roof construction, in combination, a tile support having aligned laterally projecting tile engaging members spaced apart longitudinally thereof, and refractories having lateral openings for receiving and supporting ligaments for resting upon said tile engaging members to support the refractories thereon in a row running longitudinally of the tile support, said lateral openings and supporting ligaments being of extent sullicient to permit the refractories shifting bodily on the tile engaging members in the longitudinal direction of the tile support.

9. In furnace roof construction, in combination, a tile support having aligned tile engaging members spaced apart at fixed intervals longitudinally thereof and projecting laterally at opposite sides thereof, and refractories having lateral openings for receiving and supporting ligaments for resting upon said tile engaging members, whereby a plurality of refractories may be suspended on the tile support with lateral faces in abutment, said openings and ligaments accommodating bodily shifting movement of the refractories longitudinally of the tile support while they are suspended thereon.

10. In furnace roof construction, in combination, a tile support, means for suspending same, tile retaining members spaced longitudinally on said support and refractories having supporting ligaments spanning said tile retaining members to support the refractories thereon in parallel courses with refractories of different courses in contact between the spaced tile retaining members.

11. A tile support for furnace roof sections, consisting of a bar-like body member adapted for attachment of suspension members whereby it may be hung in an approxi- -tion of the tiles width mately horizontal position and having tile engaging portions projecting downwardly and laterally from the body member and spaced apart at fixed distances longitudinally thereon, to form retaining supports for furnace roof tiles, and wherein the tile engaging portions projecting at one side of the body member are lower than those projecting at the other side, so that tiles suspended at the different sides will be maintained at different elevations.

12. In furnace arch construction, a tile support, means for suspending it in horizontal position, a plurality of tile engaging members spaced apart longitudinally on said tile su port, and a plurality of courses of roof refractories suspended on the same tile engaging members, with different courses at different elevations.

13. An element for furnace construction, consisting of a refractory tile having parallel inner and outer faces and parallel lateral faces, and having adjacent one end a hookreceiving pocket extending into the tile from its inner face and of a width comprising a substantial proportion of the tiles width, the tile having a supporting ligament spanning said pocket and integral with the material of the tile at opposite sides of the pocket, said ligament having a fiat lower surface over substantially the entire width of the pocket and having a concave margin in-set from the inner face of the tile, the inner face portions of the tile which are at opposite sides of the pocket opening and ligament being flush with the general inner face of the tile.

14. A furnace roof structure comprising, in combination, supporting beams extending over the furnace chamber, a bar-like tile support disposed at a distance below the beams, suspension members demountably connecting the tile support with the beams, tile-engaging members spaced apart longitudinally on the tile support and projecting laterally therefrom, and refractories movable into and out of supporting engagement with said tile-engaging members at the side of the tile support, whereby any refractory may be dismounted and replaced independently of the others, said tile-engaging members being arranged to support the refractories in lateral abutment to form a roof section.

15. A structural element for suspended furnace arches, consisting of a refractory tile having inner and outer faces in parallel relationship and lateral faces in parallel relationship, said tile have at one end a hook-receiving pocket extending into it from its inner face and spanned by a supporting ligament formed as a portion of the tile, the width of said pocket comprising a substantial proporbetween the lateral faces, and the supporting ligament having its outer edge concave, whereby the ligament increases in width as it approaches the sides of the pocket, to afford the ligament increased strength against shearing.

16. A structural element for suspended furnace arches, consisting of a refractory tile having its opposite lateral faces in parallel relationship and its inner and outer faces in parallel relationship and having at one end a hook-receiving pocket extending into the tile from its inner face, said pocket extending for a substantial proportion of the width of the tile and being spanned by a supporting ligament formed as an integral .part of the tile said ligament having a substantially fiat un er surface for resting on a hanger so that the tile may shift laterally on the hanger without material variation of its vertical position, the margin of the ligament being concave.

In testimony whereof I have hereunto subscribed my name.

LOUIS H. HOSBEIN.

CERTIFICATE OF CORRECTION.

Patent No. l, 870, 568.

August 9, 1932.

LOUIS H. HOSBEIN.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, line 58, for "any" read "and"; page 4, line 92, claim 2, after the word "beams" insert the comma and words the supporting beams" read with these corrections therein the case in the Patent Office.

; and that the said Letters Patent should be that the same may conform to the record of Signed and sealed this 20th day of December, A. D. 1932.

(Seal) M. J. Moore.

Acting Commissioner of Patents.

the pocket, to afford the ligament increased strength against shearing.

16. A structural element for suspended furnace arches, consisting of a refractory tile having its opposite lateral faces in parallel relationship and its inner and outer faces in parallel relationship and having at one end a hook-receiving pocket extending into the tile from its inner face, said pocket extending for a substantial proportion of the width of the tile and being spanned by a supporting ligament formed as an integral .part of the tile said ligament having a substantially fiat un er surface for resting on a hanger so that the tile may shift laterally on the hanger without material variation of its vertical position, the margin of the ligament being concave.

In testimony whereof I have hereunto subscribed my name.

LOUIS H. HOSBEIN.

CERTIFICATE OF CORRECTION.

Patent No. l, 870, 568.

August 9, 1932.

LOUIS H. HOSBEIN.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, line 58, for "any" read "and"; page 4, line 92, claim 2, after the word "beams" insert the comma and words the supporting beams" read with these corrections therein the case in the Patent Office.

; and that the said Letters Patent should be that the same may conform to the record of Signed and sealed this 20th day of December, A. D. 1932.

(Seal) M. J. Moore.

Acting Commissioner of Patents.

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