US3064594A

US3064594A - Refractory roof

Info

Publication number: US3064594A
Application number: US806550A
Authority: US
Inventors: Heuer Russell Pearce
Original assignee: General Refractories Co
Current assignee: General Refractories Co
Priority date: 1959-04-15
Filing date: 1959-04-15
Publication date: 1962-11-20
Anticipated expiration: 1979-11-20
Also published as: GB884046A; NL249933A; GB884045A

Description

R. P. HEUER 3,064,594

REFRACTORY ROOF Filed April 15, 1959 Nov. 20, 1962 rates vania Y Y Filed Apr. 15, 1959, Ser. No. 806,550 3 Claims. (Cl. 11G-99) The present invention relates to refractory roofs.

A purpose of` the invention is -to obtain more eflicient utilization of refractory brick in refractory roofs.

Y A further purpose is to hang the brick of a refractory roof by a .tabV hanger with the major axis of the brick displaced from the vertical and transverse to the working face of the roof without the use of skewbacks.

A further purpose is to provide for hanging refractory brick in pairs, one of the hangers extending vertically and the other hanger diverging from the vertical in the direction remote from the center of the arch.

A further purpose, in the hanger arrangement under discussion, is to utilize key brick in the middle and rectangular brick Vforming ramps at the sides of the roof.

A further purpose is to place the hanger tab at the side of the brick nearest to the center of the roof and protruding beyond the cold end.

Further purposes appear in the `specification and in the claims. y YIn the drawings I have chosen to illustrate one only of the numerous embodiments in which .the invention may appear, selecting the form shown from the standpoints of convenience in illustration, satisfactory operation and clear demonstration of the principles involved.

"FIGURE l is a central vertical section through the plane of the curve of a roof according to the invention. The illustration is largely diagrammatic.

FIGURE la is an enlarged diagrammatic elevation of one of the ramp brick in FIGURE l.

FIGURE 2 is a perspective of a brick employed in the roof of the present invention.

FIGURE 3 is a perspective of a U-shaped oxidizable metallic plate employed in making the brick of FIG- URE 2.

FIGURE 4 is a perspective of an alternate' top plate assembly for `forming the brick of FIGURE 2.

FIGURE 5 is a fragmentary vertical section of a prior art roof.

Describing in illustration but not in limitation and referring to the drawings:

Extensive use has been made of suspended basic refractory roofs for open hearth steel making furnaces and other metallic furnaces. Among the successful roofs of this character, are the ramp type constructions, which employ straight ramps at the sides and a flat section in the center.

The eiciency of utilization of the refractory in such construction has in many cases, however, left much to be desired. The bricks have been suspended with their major axes vertical, and since the Working face is of arch formation, the bricks as initially set are exposed at the hot ends in echelon or saw tooth formation, each brick from the outside to the center of the arch being positioned slightly higher than the next brick. lFIGURE 5 shows prior art brick hanging in an arch Whose top line of curvature is 11 and whose bottom line of curvature is 12, the effective thickness of the roof being 13, and triangular portions 14 at the bottom and 15 at the top protruding beyond the lines of curvature and not contributing to the roof thickness.

As a consequence these triangular portions 14 and 15 exposed at the hot ends and the cold ends are of no use, since the elfective thickness of the roof is actually less than the length of any one brick.

ECC

In a particular case, the amount of refractory wasted in these triangular portions is of the order of 14 percent so that the eliiciency of utilization of the refractory is only of the order of about 86 percent.

It Will be appreciated that the waste of money involved is very considerable when it is understood that the basic refractory roof for a single open hearth furnace will cost $25,000 or more.

By the present invention, this diculty is overcome. The major axis of each brick is positioned at right angles to the working face. Each brick is hung from a tab which is located at and beyond the cold end at the side of the brick adjoining the center of the concave roof.

The bricks are hung in pairs, the hanger for one brick being vertical and the hanger for the next brick being diverged away from the vertical, so that there is a slight lateral component of the weight of the brick which is exerted toward the center of the concave roof to keep t-he roof tight during assembly, since the hangers and bricks swing freely.

No skewbacks arev used, the support of the brick being entirely from above. The front and back walls are sim-ply brought into a position adjacent to the roof without supporting the roof.

Considering first the form of FIGUREv 1, I there illustrate a roof for an open hearth furnace, made up of basic refractory brick 20. At the sides are ramps 21 each made up of straight or rectangular basic refractory brick and inV the center there is a curved arch 22 made up of key brick 23. It will be understood that the key brick are of wedge shape ou` the sides 24 and 25. g

The hot ends 26 conform to the general shape of the working face of the roof and there are no wasted triangular portions of the brick. At the cold ends 27 adjoining that minor surface of the brick which is nearest to the center and protruding out beyond the cold end there is a metallic hanger tabl 28 which has an opening 30 which receives one of the hook ends 31 of theV metallic hangers.

The hangers may be arranged in pairs, consisting of an integral U-shap'ed piece of steel bar, one hanger 32 of theA pair on the side nearest the center of the roof extending down generally vertically and supporting one brick and the other hanger 33 of the pair which is more remote from the center diverging from the vertical away from the center at the lower end. Thus there is a lateral component of the weight of the brick toward the center produced by the hanger 33 which tends to keep the brick of the roof close together in suspended position. The hangers rest on longitudinal beam-s 29 o-f an overhead structure.

Each ramp brick 20 as shown in FIGURE la has a center of gravity 34 which, `as the brick hangs, is immediately below the hanger tab 28 at the upper corner on the minor surface of the brick, on the vertical line 34', so that the brick' hangs stably with its major longitudinal axis 342 directed generally toward the interior or middle of the furnace.

vOne desirable set of dimensions for the brick is 3 x 41/2 x l2 inches, the hanger tab 28 being at the upper corner of the 3 x l2 inch minor lateral face.

At the front wall there is desirably placed a water cooled metallic support 35 above the door 36 which holds a seal block 37 which is adjacent to but .not actually supporting the edge of the roof. At the rear Wall there is a sealing extension 38 which again is adjacent to but does not support the roof.

Each brick 20 will suitably be provided with oxidizable metallic plates on all lateral faces. I illustrate this in FIGURES 2 and 3 for the straight brick yand it will be evident that the same will also be true of the key brick. I preferably provide a U-shaped oxidizable metallic plate 40 which covers substantially all of two minor and one major lateral faces. The plate 40 has a base 41 of the U and

arms

42 and 43.

The arms of lthe U are preferably provided with tab extensions 44 lanc'ed from the plate and extending into and comolded into engagement with the basicrefractory 45 of the brick. In accordance with the present invention, the arm 42 of the U Whichadjoins one minor lateral face has at the cold end 27 Isuitably welded thereon a hanger tab 28, which, as the brick is made, is of L- shape, with the t-ab extension portion lying against the cold end of the brick.

I also desirably place on `the other major lateral surface of the brick an oxidizable metallic plate 46 having tabs 47 which are comolded and united with the refractory.

The plate material is desirably steel, suitably plain carbon steel such as AISI 1010 or 1030 or alloy steel such as AISi 4130 or 8620. The plates may be of a thickness varying between 1%;4. and 1A depending upon the size of the brick.

FIGURE 4 shows two parallel spaced oxidizable metall-io internal plates 57 secured las by welding to the top pl-ate 46, and embedded by comolding in the refractory of the brick. These plates 57 extend for the preponderance of the length of the brick parallel to the 3 x l2 inch minor lateral face of the brick in the example given.

The choice of the extent of the ramps and the extent of the curved arch in the roof of FIGURE 1 will vary, but it is usually preferable to make the curved arch portion about ofthe total width of the roof.

In view of my invention and disclosure, variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benets of my invention without copying the structure shown, and I, therefore, claim all such insofar as they fall within the reasonable spirit and scope of my claims.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. A basic refractory roof which widthwise is higher in the middle and lower at the sides, comprising a plurality of basic refractory brick in contact side by side, each brick having lateral faces, having a working face exposed at the interior of the roof and having a major longitudinal axis transverse to the Working face, the

working faces of the bricks contributing regularity of line to the interior of the roof and the bricks on each side of the middle of the roof hanging with their major longitudinal axes displaced in directions toward the space under the middle of the roof, there being a hanger tab on each brick adjoining one lateral face of the brick at the cold end of the brick, said one lateral face of the brick being the most inward lateral face of the corresponding brick along the width of the roof, a plurality of supports above the-roof running in the direction parallel to the length of the roof and hangers extending from said supports to the tabs in pairs, one hanger extending generally vertically and freely engaging the tab of one brick, and the other hanger diverging from the vertical in the outward direction along the width of the roof and freely engaging the hanger tab of the next brick outward along the width of the roof, said next brick thus exerting a lateral pressure component toward the middle of the roof against said one brick to eliminate need for support and stabilization of the roof on skewbacks.

2. A refractory roof of claim 1, having a curved arch of key brick at the middle and side ramps of rectangular brick at each side. t

3. A refractory roof of claim 1, having a curved arch of key brick at the middle and having at each side a ramp of rectangular brick, the center of gravity of each rectangular brick in the ramps being beneath the point of engagement of the hanger tab.

References Cited in the tile of this patent UNITED STATES PATENTS 2,163,435 Pollen June 20, 1939 2,187,669 Stewart Jan. 16, 1940 2,529,607 Heuer Nov. 14, 1950 2,600,460 Antill June 17, 1952 2,652,793 Heuer etfal Sept. 22, 1953 2,673,373 Heuer Mar. 30, 1954 2,786,235 Schieferstein Mar. 26, 1957 2,880,462 Lehman Apr. 7, 1959 2,902,721 Heuer Sept. 8, 1959 2,932,265 Heuer Apr. 12, 1960 OTHER REFERENCES Heuer, R. P. and Fay, M. A.: The All Basic Open Hearth Furnace, publication by General Refractor-ies Company, pages 5 to 8.