US3005424A - Refractory roof construction and refractory brick - Google Patents

Description

Oct. 24, 1961 R. P. HEU'ER 3,005,424

REFRACTORY ROOF CONSTRUCTION AND REFRACTORY BRICK Filed Feb. 19, 1959 2 Sheets-Sheet 1 r? W i y ;d Jaw;

/ INVENTOR ATTO RN EYS Oct. 24, 1961 R. P. HEUER & 4

REFRACTORY ROOF CONSTRUCTION AND REF'RACTORY BRICK Filed Feb. 19, 1959 2 Sheets-Sheet 2 INVENTOR %5 45 %f Ewye/Perce #emer United States Patent Ofiice 3,005,424 Patented Oct. 24, 1961 vania Filed Feb. 19, 1959, Ser. No. '794,380 6 claims. (Cl. 110-99 The present invention relates to improved refractory roof constructions and refractory bricks therefor.

A purpose of the invention is to assemble a basic refractory roof which will give better service under the exacting conditions of an open hearth steel-making furnace or other similar high temperature furnace.

A further purpose s to permit more rapid assembly of a spring arch basic refractory roof.

A further purpose is to obtain longer life from a basic refractory roof of Sprung arch Construction.

A further purpose is to permit quick adjustment for slight variations in dimensions of Component parts in assembling a basic refractory brick roof.

A further purpose is to extend girder plates in the direction between the skewbacks of a Sprung arch in which the girder plates le between rows of refractory bricks and eXtend .out at the cold ends for a substantial distance, suitably at least one-fifth of the length of the brick, and to support the brick by hangers which extend from the cold end of the girder plates to tabs or the like at the cold ends of the bricks.

A further purpose is to mount pairs of bricks either in different rows or in the same row from a single hanger as above mentioned.

A further purpose is to make suitable allowance for expansi on in the radial joints by providing asbestos cushons.

A further purpose is to locate the asbestos cushions between the refractory of the brick and its oxidizable metallic plate on a radial face of a Sprung arch.

Further purposes appear in the specification and in the claims. t

In the drawings I have chosen to illustrate a few only of the numerous embodiments in which my invention may appear, selecting the forms shown from the standpoints of convenience in illustration, satisfactory operation and clear demonstration of the principles involved.

FIGURE 1 is a diagrammatic vertical section of a Sprung arch in acoordance with the invention. The righthand side of FIGURE 1 shows only the overhead structure, the hold-downs, the beams and the girder plates, while the lefthand portion of FIGURE 1 includes the arch bricks and the hangers. It will be understood of course that in the completed arch the righthand portion will be constructed in the same manner as the lefthand portion.

FIGURE 2 is a fragmentary enlarged radial section of FIGURE 1 on the line 2-2.

FIGURE 3 is a fragmentary end view of FIGURE 2.

FIGURE 4 is a fragmentary enlargement of a portion of FIGURE l showing the bridge Connector at a beam.

FIGURE 5 is a fragmentary section of 'FIGURE 1 on the line 5-5 showing the hold-down.

FIGURE 6 is a fragmentary section in a plane parallel to the paper in FIGURE 1 of a girder plate and the arch bricks, showing the use of asbestos cushions at the hot ends outside the oxidizable metallic plates on the radial faces of the brick.

FIGURE 7 is an enlarged fragmentary view corresponding to a portion of FIGURE l but showing a modification.

FIGURE 8 is a fragmentary section on the line 8-8 of FIGURE 7.

FIGURE 9 is a fragmentary plan view of the structure of FIGURES 7 and 8 showing the bricks and hanger tabs and omtting the beams and hangers.

FIGURE 10 is a view similar to FIGURE 7 showing a further modification. a

FIGURE 11 is a fragmentary plan view of the structure of FIGURE 10 omitting the beams and hangers.

FIGURE 12 is a perspective of an individual refractory arch brick according to the invention.

FIGURE 13 is a side elevation of an arch brick according to FIGURE 12.

FIGURE 14 is a perspective showing a U-shaped oxidizable metallic plate having asbestos cushion material at the hot end between the refractory and the plate.

FIGURE 15 is a view similar to FIGURE 14 showing a variation in which the asbestos cushion material extends the entire length of the brick at the inside of the plate.

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

Extensive use is now being made in the prior art of basic refractory roofs for open hearth furnaces. Present constructions are expensive in materials because of the large amount of steel supporting-structure required, and are particularly expensive to assemble because of the large amount of labor needed.

By the present invention it is possible to obtain a Sprung `arch refractory roof for an open hearth or similar furnace which is very quickly assembled, at low cost.

Furthermore, the invention lends itself to production of a roof which is less likely to respond abnormally to temperature changes and therefiore less likely to buckle or otherwise fail by localized Stress concentration.

Considering first the form of FIGURES l to 6, with the refractory brick of FIGURES 12, 13 and 14, I illustrate a furnace 20, suitably an open hearth, having a front wall 21, a back wall 22 and a Sprung arch roof 23 which runs length wise of the furnace. At the front there is a beam 24 which supports thereon a front skewback 25 and at the rear there is a beam 26 which supports real' skewback 27. These skewbacks nin the full length of the furnace and at least partially support the arch brick.

Between the skewbacks extend a series of rows of key brick 28, which are desirably of the character shown in FIGURES 12, 13 and 14. Each of the brick has a refractory mass 30 of basic refractory, suitably chrome, magnesia, chrome-magnesite or nagnesite-ch'ome, of the character described in my prior U.S. patenta :In any case the brick contains at least 10 percent of magresia by weight. Preferably comolded with the refractory is a U-shaped oxidzable metallic plate 31 having a base of the U 32 and arms of the U 33. The base of the U is on one primary lateral face 34 of the brick extending preferably the full length and in any case over the major portion of the face, and the arms of the U are on minor lateral faces 35 of the brick extending over the preponderant area of the minor faces. Parallel with the major lateral face 34 there is a major lateral face 36 which is provided with an oxidizable metallic plate 37 extending over preferably all and in any case the preponderant area. The plate 37 suitably has Secured thereto internal plates 38 which are comolded in the interior of the brick and extend over the major portion of the cross section. The internal plates 38 are preferably in U form and the base of the U 40 is secured as by spot welding at 41 to the plate 37.

To assist in anchorage of the sides 33 of the U there are desirably projections 42 lanced from the arms of the U and embedded in the refractory by comolding.

The plate 31 at the cold end desirably has a hanger tab 43 provided with a hook engaging hanger recess 44 and suitably Secured to the plate as by spot welding at 45. When molded, the hanger tab 43 is suitably flush &005,424c

with the end of the brick but is later bent out to extend radially or in the direction of the length of the hanger.

As well known, all of the oxidizable metallic plates are relatively thin, suitably of a thickness between and Mi" and desirably of plain carbon or low alloy steel, for example AISI 1010 or 1035. The oxidizable metallic plate oxidizes and reacts with the basic refractory as well known in the art.

In the structure' of the invention as shown inFIGURES 7 to 11, the internal p-lates 38 do not extend radially, and therefore no advantage is obtained from their reaction which tends to counteract the efect of expansion when they extend radially. It is therefore important, in the preferred enbodiment, to locate at at least certain of the radial joints at the hot end, asbestos cushion material or the like which will take up for growth when the external metallic plates oxidize and react. Even where internal plates extend in the radial direction as in FIGURE 1, it is desirable to use asbestos cushions at the hot ends of every second brick illustrated at 46, and these are shown in FIGURE 6 applied external to the plates at the radial joints extending only of the order of Mi to of the distance from the hot end to the cold end of the brick.

Unfortunately, the asbestos cushion material when applied externally is likely to be abraded and damaged in installation, and it is difficult to ship bricks with asbestos cushion material cemented or otherwise applied to the radial faces on the outside.

`I illustrate, therefore, in FIGURES 12, 13 and 14 a layer of asbestos cushion material 46' extending between the refractory and the metallic plate near the hot end at the inside of the plate, and comolded in place. This is suitably accomplished by applyng the asbestos cushion rnaterial to the plate before molding the brick. The asbestos cushion material can be cemented to the plate if desired.

in some cases as shown in FlGU RE 15, the comolded asbestos cushion material 46 extends over the entire radial face of the brick inside the plate and is comolded in place. The brick of FIGURES 12, 13 and 14 are preferably used in FIGU RES 7 to 11.

Between certain rows of arch brick, extending in the direction from one skewback to another, are placed metallic, suitably steel girder plates 47 which suitably extend to the hot end and extend beyond the cold end in the radial direction for a distance of at least and preferably at least Mi of the length of the brick. Therefore the girder plates unlike those employed by Mohr US. Patent 2,577,428 are protected against destruction from the effects of temperature and chemical reaction with the basic refractory.

The girder plates are suitably of relatively short length sufficient to support 9 or bricks in the preferred embodiment. At the ends of the girder plates toward one of the skewbacks, beyond the cold ends of the brick, the girder plates are suitably recessed as shown at 48 and through the recesses suitably just beyond the cold ends of the brick extend suitably steel beams 50 running transverse to the girder plates and desirably not extending beyond the cold ends of the girder plates. The support of the girder plates on the beams is accomplished by bridging connectors 51 suitably of steel, 'best seen in FIG- URE 4, which extend above the beams and are Secured to the girder plate by bolts or other fasteners 52 at each end.

Sutably supported at the front and back of the furnace is an overhead steel supporting structure 53 which is connected to the beams by hold-downs 54 suitably consisting of pipes which at the lower end are boted at 55 to angles 56 which are riveted at 57 to the beams, and which at the upper end extend through tubular connectors 59 secured to the supporting structure, and are locked in place by top and bottom pins 58. It will be noted that the hold-downs extend radially and function to prevent a tendency of the roof to buckle.

The bricks of two adjoining rows are arranged, as

'4 shown best in FIGURE 2, so that their hanger tabs 43 are adjoining and the hanger 60, suitably a steel rod, has at the lower end a hook end 61 which passes through the hook recess 44 of two hanger tabs. The hanger then extends diagonally upward and at the upper end is bent around as by the use of a pipe to form an upper hook end 62 which in the form of FIGU-RES 1 to 6 lies in the same plane as the lower hook end 61. Since the bending is accomplished at assembly, the upper hook end 62 automatically adjusts for any variation in dimensions.

Thus it will be seen at each location as shown in FIG- URE 2, the girder plate 47 supports four bricks in four different rows, two on each side.

Other arrangements of bricks are desirable in some cases and in FIGURES 7, 8 and 9 I show an -arrangement using wedge brick which reduces the skewback pressure by supporting the bricks singly. In this form, each hanger 60 supports one brick 30' by connection to its hanger tab, and the upper hook end 62 of the hanger is in this form located in a plane at right angles to the lower hook end 61', rather than being in the same plane. Thus in the form of FIGURES 7, 8 and 9, there is one brick supported by each hanger and the brick is located in a row extending between the skewbacks immediately on one side or the other of the girder plate.

-FIGURE 8 shows the major face of the brick while FIGURE 7 shows the minor face of the brick.

In some cases it is desirable to have each hanger support two wedge bricks which are located in the same row. In the form of FIGURES 10 and 11, the lower hook end 61' is in a plane at right angles to the upper hook end 62 of the hanger and extends through hanger tabs 43 of two bricks in the same -row adjoining the girder plate so that girder plates are used between each alternate row of bricks extending from one skewback to another.

It will be evident that according to the present invention it is possible to obtain very much more rapid assembly of an economical basic Sprung arch roof.

While it has been indicated above that the metallic plates on the brick will preferably be of plain carbon or low alloy steel, the hanger tabs themselves will preferably be formed of stainless steel such as a straight chromium grade containing 16 or more percent of chromium or a chromium-nickel grade containing 18 or more percent of chromium and 8 or more percent of nickel. This subject matter is contained in my copending application Serial No. 7 88,123 for Basic or Neutral Refractory Brick, filed January 21, 1959.

In View of my invention and disclosure variatons 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 benefits 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 refractory arch, spaced skewbacks, refractory brick extending between said skewbacks in arch form rows and supported at least partially on the skewbacks, an overhead supporting structure, beams supported from said overhead supporting structure and extending above said arch fo im rows in a longitudinal direction which is transverse to the rows of brick, said beams being substantially parallel and spaced from each other adjacent the cold ends of the brick, oxidizable metallic girder plates extending between rows of the arch brick in the direction from one skewback toward the other, and said plates extending from a position adjacent the hot ends of the brick and having portions extending out radially beyond the arch brick from the cold ends, substantially to a position beyond said beams, means for interconnecting said girder plates with the beams, hanger attachments extending beyond the cold ends of the brick, and hook hangers having hook portions extendi g Ove the gi-rder plates beyond the arch form rows and having hook portions which engage the hanger attachments.

2. An arch of claim 1, in which the girder plates are 'recessed at their radially extending portions to accommodate the beams, the beams extending through the recesses, and the means for connecting the girder plates to the beams comprises bridging connectors from one girder plate to another across the beam.

3. An arch of claim 1, in which each hook hanger at one end engages the hanger attachments of two bricks in different rows.

4. An arch of claim 1, in which the hook hanger at one end engages the hanger attachments of two bricks i the same row.

5. An arch of claim 1, in which a plurality of radial lateral joints between brick of said arch rows of brick each includes an oxidizab-le metallic plate and asbestos cushion material, said asbestos cushion material being a member of a brick of the correspond'ng row in which said joint is formed, and said oxidizable metallc plate being a member of one of the brick of the row in which said joint is formed.

6. An arch of claim 1, in which a pluralty of radial lateral jo-ints between brick of said arch rows of brick each includes an oxidizable metallic plate and asbestos cushion material, said plate and cushion material being members of a brick of the correspondng row in which said joint is formed, and said cushion material being disposed between said plate and the basic refractory of the brick of which said plate and cushion material are members.

References Cited in the file of this patent UNITED STATES PATENTS 1,885,800 Burnet Nov. l, 1932 2,577,428 Mohr Dec. 4, 1951 2,641,207 Pollen June 9, 1953 2,652,793 Heuer et al. Sept. 22, 1953 FOREIGN PATENTS 168,088 Australia Sept. 20, 1956 865,537 France Mar. 3, 1941 %2,665 Germany Jan. 24, 1955 %8,265 Germany Jan. 26, 1956 OTHER REFERENCES Heuer, R. P.: "The All-Basic Open Hearth Furrace," pp. 5-10 published by General Refractories Company.

Disclaimer 3,005,-4:*24 ;-:Bu88ell Peame Heue, Bryn Mawr, Pa. REFRACTORY RooF CON- STRUCTION AND REFRACTORY BRICK. Patent dated Oct. '24, 1961.

Disclaimer filed Apr. '27, 1962, by the assignee, General Refmctom'es *Company Hereby enters this disclaimer to all claims of said patent.

[Ofiimal Gazetat@ J um 5, 1962.]

Disclaimer 3,005,424:. -l3ussell Pecwce Huew, Bryn Mawr, Pa. REFRACTORY RooF CON- STRUCTION AND REFRAGTORY BRICK. Patent dated Oct. *24, 1961. Disclaimer filed Apr. 27, 1962, by the assgnee, General Refmctom'es Uomyxmy. Hereby enters this disclaimer to all clams of said patent.

[Ofimcl Gazette Ju/ne 5, 1962.]

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