US2665895A - Soaking pit curb wall with fixed elevation - Google Patents

Description

Jan. 12, 1954 c. L. HERMAN SOAKING PIT CURB WALL W ITH FIXED ELEVATION 3 Sheefs-Sheet 1 Filed April 50, 1953 N 4 W 2 A a a.

Jan. 12, 1954 c. L. HERMAN 2,665,895

SOAKING PIT CURB WALL WITH FIXED ELEVATION Filed April 50, 1953 3 Sheets-Sheet 2 IN VEN TOR.

///5 ATTORIVZ-V Jan. 12, 1954 c. HERMAN 2,665,895

SOAKING PIT CURB WALL WITH FIXED ELEVATION Filed April 50, 1953 5 Sheets-Sheet 3 INVEN TOR.

Patented Jan. 12, 1954 SOAKING PIT CURB WALL WITH FIXED ELEVATION Carl L. Herman, Canonsburg, Pa., assignor to Amsler Morton Corporation, Pittsburgh, Pa., a

corporation of Delaware Application April 30, 1953, Serial No. 352,229

11 Claims. 1

This invention relates generally to soaking pits or other furnaces similarly constructed with a large furnace chamber opening, and more particularly to the curbing or perimeter surrounding the furnace chamber opening which must be of fixed elevation or position. Yet, the walls of the furnace chamber must be permitted to expand or contract without losing the seal between the closure and the opening.

The problem of maintaining the seal around a large furnace opening, such as a pit furnace is difficult. The masonry, forming the furnace chamber, must expand and contract considerably more than that of the framework that holds the curbing, supports cover carriages if any, and also supports the seal that extends completely around the furnace opening. The way these problems have been coped with heretofore is to construct the furnace so that the whole of the structure may; expand and contract uniformly. A small leak in the seal would not be too bothersome but when the furnace pressures show a large differential, then a leak in the seal is troublesome.

The vast difference in the expansion and contraction of the outer materials and the furnace chamber linings causes the seal to be interrupted, and the furnace to distort to such a degree that the. cover or door will not fit properly, which results in a leakage of the heat and gases or a leakage of air into the furnace chamber depending upon the pressure conditions in the furnace. Such a furnace structure cannot be depended upon for good operation over a considerable period of time. The curbing twists and gives trouble with the track supported carriage for lifting and moving the covers from the furnace chamber openings such as a soaking pit.

The principal object of this invention is the provision of a curbing or perimetral margin surrounding a large furnace opening that is fixed relative to the foundation of the structure while permitting the furnace walls to expand and contract without a'ffecting the curbing or the .seal of the furnace opening supported by this perimetral margin.

This curbing or perimetral opening of a fur-.

nace chamber has a fixed elevation or location and permits the seal to be maintained regardless of the temperature or temperature changes in the furnace chamber. This is accomplished by supporting the curbing from the outer wall structure which is made of fabricated steel. The

curbing then ties in with the furnace Wall struc-- ture by providing a series of stepped spaces that are independently shut off from each other when expanded and which permit the ready movement of the furnace wall or curbing structure without completely closing the stepped spaces in which hot air or gases are entrapped. The curbing masonry material, being relatively small as compared to that of the furnace walls, will not expand or contract to such a degree as to disturb the seal or the track which supports the cover carriage.

The curbing is then supported to a degree and actually insulated from the furnace walls which provides improved furnace structure in that the curbing does not get overheated or destroyed, and the walls of the furnace chamber may be readily replaced without disturbing the curbing. The walls have all the freedom of expansion or contraction without interrupting the seal or in otherwise changing the curbing.

Where a center wall is employed between two furnace chambers, the curbing may be hung from a bridge member, and thus be independent from the wall but still be sealed therewith and carry two sealing troughs for independent covers.

This invention is better illustrated on a pit furnace as it presents more problems in that the furnace opening is upward, and the cover must be removed by a carriage supported by the rails carried on the same structure supporting the curbing.

Other objects and advantages appear hereinafter in the following description and claims:

The accompanying drawing shows for the purpose of 'exemplification without limiting-the invention or claims thereto certain practical em-' bodiments of the invention wherein:

Fig. 1 is a view in vertical section of a side wall of a soaking pit furnace with the carriage removed.

Fig. 2-is a view in horizontal section taken on the lines 2-2 of Fig. 1.

Fig. 3 is a view in vertical section of an end wall of a soaking pit furnace showing a cover in place. I

Fig. 4 is aview in vertical section of a common wall between adjacent soaking pit furnace chambers.

Fig. 5 is a view in horizontal section taken on the line55 of Fig. 4.

Referring to Fig. 1 the furnace soaking pit is provided with a furnace chamber I with a curb 2 formed by the wall as illustrated in Fig. 2, the liner of which is thin in its intermediate portion and heavier at the ends as indicated at 3. This wall also tapers upwardly to the curbing asindicated at 4. r e v H The'furnaee wall structure is lined with a fire stone or silica brick 5. This is backed up by a back-up wall 6 of fire brick of secondary quality, which is covered with an insulation as indicated at i that may be a diatomaceous earth with asbestos fiber binder. This insulation is then enclosed by a steel shell or wall 8.

The steel wall 8 is braced with vertical stanchions and is a structural support for the furnace. This wall has secured thereto the seat or shelf member Ill which extends around the pit and is supported at intermediate sections. by the triangular brace plates II that are welded tathe underside of the shelf in and to the wall 8. The insulating section 1 extends up to the underside of the shelf in and above the wall 6.

The tops of the inner lining 5 and the back-up wall 6 are formed in steps such as. indicated at 1.2,. i 3, I4, l5, and 16, the latter being exposed to. the. chamber of the pit. These steps sometimes vary in width and height depending upon the character of the curbing to be constructed. However, they provide pockets or air spaces which after being heated become isolated from one another and form expansion spaces between these wall sections and the curb structure.

The steel wall 8 extends clear to the top of the furnace as shown and supports the curbing. A small section of insulating material (I is provided along the inner face of the steel wall 8 and against which the ends of the special shapes of super duty fire clay blocks are mounted on the curbing. These blocks form the curbing and the lowermost block is the smallest block and the uppermost block is the largest block. As illustrated' in Fig. 1, the blocks numbered l8, I9, 20, M, 22, and 23, and each block asillustrated in Fig. 2, is provided with a vertical slot 24 on its outer face for receiving one half of the head of the wall-tie member 25, the other half being received in a similar vertical groove 24 of the adjacent block.

The wall-tie members 25, as shown in Fig. 6 are short T-headed sections that are provided with a bolt section 26 formed integral therewith and which extend through the slot 21 formed by the spaced angle plate 28 secured to the outer surface of the steel wall 8. Washers 30 are placed under the nuts ill for securing the short T-headed wall ties against the outer edges of the angle plates 28 for supporting the ends of the stepped curbed blocks 8 to 23 inclusive to the outer steel structure. Each T-headed wall-tie member is engaged in the slots 24 of sub-j acent blocks as well as laterally adjacent blocks as indicated in Fig. 1.

Since the lowermost block is resting upon the seat of the shelf in andthe other blocks are resting upon each immediate sub-jacent block in turn, the position of the inner ends of the blocks is fixed relative to the curb line and the pit. The blocks '20 and 2! are of the same length which provides a deeper vertical seal between the steps l4 and 15. However, the steps i246 are air steps and thus become sealed off and independent from one another upon expansion of the refractory wall below the blocks Hi to 23, causing the latter t0 engage the vertical Wall formed by the steps l2-l6.

The opening above the step I6 is filled with Gunite after expansion has taken place in the burning of the furnace walls. However, the walls may expand and contract vertically and without disturbing the curbs owing to the fact that the walls can breathe and move in the air spaces formedabove the steps I! to 6 inclusive. The

4 caulking material in the space above the step [6 may be such that it is soft and will withstand the breathing of the furnace wall below the curb line.

The curb masonry 2 is made of span-resistant refractory shapes and it is. supported on. the uppermost special shaped super duty fire; clay block numbered I8 to 23. This curb brick is capable of withstanding 2,600 F. and is dished to receive the trough 32 made of an alloy steel for the purpose of receiving silica sand that is employed to receive and seal the depending seal flange on the cover that closes over the pit opening.

The steel wall 8 is also provided with a stiffener, angle 33 which is secured to the outer face of the steel wall 8 adjacent the lower end of the triangular gusset plates 1 I and aids in carrying the fabricated structural beam member 311 made of two spaced channel members with an intermediate H-beam therebetween which further stiffens the wall. This structural beam member is referred to as the rail girder and supports the channel members 35 that extend transversely 'of the girder 34. These channel members are placed back to back and carry the walkway plate 35 on which are mounted the rail 37 that supports the carriage that raises and transports the furnace pit covers.

The walkway plate 36 extends over the box formed by the stiffener angle plate 33 and is attached to an angle plate 38 which is secured to the upper end of the steel wall 8 and to the end of the walkway plate 36. It is preferable to allow a clearance between the upper and lower ends of the angle plates 28 and the sti'fiener angle support member 33 and the angle plate 38 so that these members may breathe with the expansion and contraction of the wall without engaging and binding against these transverse supports.

As shown in Fig. 2, the special shaped super duty fire clay blocks [8 to 23 which support the curbing have an offset section as illustrated at 40 and 4! so as to interlock the adjacent blocks relative to each other as well as having them interlocked by the T-headed wall-tie 25. The uppermost special shape 23 is the longest of the group and provides a long seal off area for the underside of the insulating curb line brick 2.

The structures as shown in Figs. 1 and 2 represent the outside or side wall of the pit and the structure as illustrated in Fig. 3 is similar to the structures as illustrated in Fig. l but represents the end wall of the pit adjacent to the recuperators. The number and names of the parts shown in Fig. 3 and their relationship with each other is the same as the structure illustrated in Fig. 1. However, the rail girder 34 has been replaced by the fabricated beam structure 43, the lower end of which is supported by the angle plate 44 secured to the outer wall 8, thereby stiffening the outer wall, and is braced intermediate of its ends and adjacent the seat It by the channel member 45' which functions as a stiifener member for supporting the wall at the seat l0 and also for aiding and stiffening the girder member A3.

The upper end of the girder member 43 supports the outer curb member 46 which rests on. the expansion layer that is defined by the angle members 48 and 49, the latter being secured to the upper end of the outer steel wall 8. This outer curb member 46 is mounted in spaced relation with the floor member 553 which is supported by the girder 5i independent of the pit. furna e;

This floor member 50 protects the recuperator' employed to heat the gases for operating the fur-;

nac'e' which floor members 50 are ordinarily positioned intermediate pairs of pit furnaces and are used to temporarily support the pit cover when the same is not in position over the pit.

' The pit cover 52 is provided with a downwardly extending sand-sealing skirt 53 which seals the opening of the pit. The cover member is provided with a series of lining clocks 54. These blocks are supported from the framework as illustrated at 55 and the frame of the whole of the cover is supported at the four corners of the pit. Thus, there is no weight of the cover on the curbing. The furnace pit has upwardly supporting members at the four corners of each pit that are carried from the foundation for the purpose of supporting the cover frame alone. The cover is raised from the pit by the cover carriage that spans the pit and runs on the track, one rail of which is shown in Fig. 1. The cover is then traversed over the section 58 leaving the pit open to the extent required for removal of the-billets therein.

" Referring now to Figs; 4 and 5 which show an intermediate wall section of two adjacent pit chambers, pit i is illustrated on the right and pit 68 illustrated on the left. The inner lining ii of silica brick has a complementary lining in the next adjacent pit, and there is only one back-up wall made of first quality brick which is indicated at El which forms the back-up wall for each pit. The upper surface of the back-up wall BI is provided with the inner shelves 62, 63, and 6d.

The inner walls 5 are provided with the shelves 65, 66, 61 and 68 which correspond to the shelves 12 to IE as shown in Figs. 1 and 3 and are of the same elevation. The air space provided above each of these shelves is occupied by a specially shaped refractory block such as indicated at 10, H, 12, I3, 14, I5, and 16 each of which match each other as they extend upwardly along both sides of the intermediate soaking pit wall.

Each of these blocks is provided with a T- headed tie member such as indicated at 11, that are provided with spaced ears for bolting the same on the radial flanges 18 which are positioned on and secured to each side of the beam member 88. The beam member 80 is fabricated from the opposed channel members 8| which are spaced apart and provided with an inner box member 82 supported on angle 83.

The upper flanges of the oppositely disposed channel members 8| form the principal structure of the beam and are provided with a grating or walk 84 that is held in place by the long flanges and the pan members 85 which contain the sand for the sand seal 86 for each pit. The curbing blocks 81 are supported on the topmost special form blocks 16 and are also tied together in the ordinary masonry way with the blocks 16 and abut against the outer flanges of the sandseal trough members 85.

As shown in Fig. 5 the special form blocks 16 have vertical angle members 88 and 89 which interlock with each other and aid in pulling the block members in position. The T-headed members l! are also carried by slots 24 that are constructed in the same manner illustrated by the T-headed member in Fig. 2. It will be noted that the lowermost blocks '10 and H are secured by the wide T-headed member 90 which is bolted to the bottom flanges of the channel members 8! as indicated in Fig. 5, and they are not bolted to the radial plates 18 as these plates are employed to hold all of the other special block forms,

The shelves 62 to 68 inclusive also form air spaces between the top of the center wall and the special shaped blocks, yet, each of the spaces formed are sealed from each other and permit relative longitudinal expansion and contraction. The curb being of a lighter masonry section and being supported by rigid structural members that are carried from the four supports at corners of the pit directly mounted on the foundation will not vary in height. However, the heat of the large and heavy expanse of masonry formed by the pit walls, both the outer wall and the intermediate wall are permitted to expand and contract and thus take up space allowed between the steps yet, there can be no leakage into or from the furnace pit chambers to the outside or to adjacent pit furnace chambers by reason of these closed and interlocking independent step sections of the furnace wall.

The outer wall construction and the common wall construction are somewhat similar to each other varying only in the manner in which they are supported. However, the specially shaped blocks are supported and keyed with each other in the same manner, and they are both hung from the steel structure rather than being hung or otherwise supported by the masonry forming the wall of the pit chamber.

I claim:

1. A furnace structure comprising a bottom, an annular wall forming furnace chamber with said bottom, a frame extending above and on the outer side of said annular wall, an annular curb supported by said frame to extend over the top of said annular wall and in spaced relation therewith to allow for sealed vertical expansion between the top of the annular wall and the annular curb, a roof supported independently of said annular curb and forming a closure for the top of said furnace chamber, and sealing means between said roof and annular curb to isolate said furnace chamber as an independent pressure chamber.

2. The structure of claim 1 characterized in that said sealed vertical expansion between the top of said annular wall and the underside of said annular curb are formed in a series of independent steps permitting expansion and contraction of the annular wall relative to the annular curb.

3. The structure of claim 1 characterized in that said sealed vertical expansion between the top of said annular wall and the underside of said annular curb are formed in a series of independent steps permitting expansion and contraction of the annular wall relative to the annular curb, the steps formed between the annular wall and the annular curb are laterally blocked off from one another to provide independent expansion chambers.

4. The structure of claim 1 characterized in that said annular curb is made up of a series of masonry forms each supported directly from the frame independently of said annular wall.

5. The structure of claim 1 characterized in that said annular curb is made up of a series of masonry forms each supported directly from the frame independently of said wall, adjacent ceramic forms making up the annular curb being interlocked in offset steps with one another.

6. The structure of claim 1 characterized in that said annular curb supports an annular sand seal into which an annular sand seal skirt projects to seal said furnace chamber.

7. The structure of claim 1 characterized in ace-aces that. said furnace is'provided with a: plurality of chambers,- and said frame includes. a transverse beamsupported above a center wall section div-iding said furnace chambers.

it. The structure of claim 1 characterized in that said furnace is provided with a plurality of chambers, saidframe includes a transverse beam supporting a center curbabove a center wall dividing said. furnace chambers; the top of said center wall and the underside of the center curb thereover are formed in a series of independent steps permitting expansion and contraction of the center wall relative to the center curb.

9. The structure of claim 1 characterized in that said furnace is provided with a plurality of chambers, said frame includes a transverse beam supporting a center curb above a center wall dividing said furnace chambers, the top of said center wall and the underside of the center curb thereover are formed in a series of independent steps permitting expansion and contraction of the center wall relative to the center curb and the steps formed between the. center wall and the center curb are blocked, off: from, one another to,

provide, independent expansion chambere.v

10; The structure of claim 1 characterized in that said furnace is provided with; a plurality of chambers, said frame includes a transverse beam supporting a center curb above a, center wall d-ividing said furnace chambers, and said center curb is made up of a series of masonry terms each supported directly from said beam independently of said wall.

11. The structure of claim 10.- characterized in that said masonry forms on the; center curb are interlocked transversely of the: curb.

CARL-L.

References Cited in the,- file Of. this patent UNITED STATES PATENTS Number Name Date 693,252 Fiske v Feb 11, 1902 925,519 Simkins June 22, 19119 1,432,737 Adams i O,ct. 24,1922 2,596,180 Sherman r May 13 1952

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