US3181486A

US3181486A - Refractory structure

Info

Publication number: US3181486A
Application number: US212537A
Authority: US
Inventors: Donald F King
Original assignee: Harbison Walker Refractories Co
Current assignee: Harbison Walker Refractories Co
Priority date: 1962-07-26
Filing date: 1962-07-26
Publication date: 1965-05-04
Anticipated expiration: 1982-05-04

Description

May 4, 1965 D. F. KING 3,181,486

REFRACTORY STRUCTURE Filed July 26, 1962 rzvmvron Dam 14p 1-7 KIA/6 ATTO/Q/VE) United States Patent 3,181,486 REFRACTORY STRUCTURE Donald F. King, Pittsburgh, Pa., assignor to Harbison- Walker Refractories Company, Pittsburgh, Pa, a corporation of Pennsylvania Filed July 26, 1962, Ser. No. 212,537 9 Claims. (Cl. 11li99) This invention relates to refractory structure and cased refractory shapes therefor. More particularly the invention relates to refractory structure and improved arrangements for reinforcing basic refractory brick useable therein.

It is well known and understood in the art that refractory shapes, such as basic refractory brick which are to be used in certain environments in various metallurgical furnaces, such as open hearth furnaces, should be reinforced with some manner of oxidizable metal casing, intended primarily to prevent spalling of the basic brick and to generally improve its structural strength.

However, when such metal reinforcement is present within a furnace wall or roof, it has disadvantages as well as advantages. Oxidation of the metal in service results in a desirable tightening and welding between the separate units which make up the wall and roof, but when excess metal is present, expansive forces are exerted which may be disruptive, causing the exposed faces of the cased refractory shapes to peel away thus negating the desired anti-spalling function of the metal. The excess metal also sometimes makes subsequent patching operations difficult. Further, the metal and the products of its oxidation are not nearly as refractory as the refractory shapes they are intended to reinforce and when present in excess amounts, or in roofs or walls which become excessively hot, may be the cause of loss of structural stability. Further, since the metal has substantially higher thermal conductivity than the refractory portion of the cased structure, excessive use of metal contributes to high temperature loss through the furnace.

A peculiar disadvantage of metal reinforcement within open hearth structures using large volumes of oxygen occurs as a result of localized reducing conditions which may prevent oxidation of the metal before melting occurs. when melting does occur, loss of metal results in loss of structural stability.

The use of metal reinforcement within basic furnace structures thus, while considered necessary, represents a distinct compromise. I have discovered that the advantage of the metal reinforcement can be maintained, while lessening its disadvantages, even in steel-making furnaces using large volumes of oxygen, by a novel metal reinforcement configuration which maintains the metal to refractory ratio of the cased refractory shapes at a minimum consistent with adequate reinforcement and welding.

Spalling resistance of basic refractory brick in service is known to be inversely proportional to the cross section of the exposed faces and it is, therefore, desirable to provide brick units with minimum cross sections. The smaller the cross section of the individual brick, however, the greater the number required to install a furnace wall or roof of given area.

One prior art manner of easing basic refractory brick has been to wrap metal sheeting around the four long faces of the brick, i.e. about the two 9 x 4% and two 9 x 2 /2" faces of a standard 9 x 4 /2 x 2 /2" unit, for example. This arrangement has been reasonably satisfactory in many installations, but there was considerable incidence of brick falling out of their enclosing metal sheaths during shipping and handling. Further, when brick of smaller cross section were prepared, the relative amount of metal 3,l8l,486 Patented May 4, 1965 to brick in a given installation increased and, in many instances, the disadvantages of the metal at high temperatures-as previously described-outweighed its reinforcing advantages and unsatisfactory furnace campaigns were experienced.

Accordingly, it is an object of this invention to provide an improved metal reinforced basic refractory shape. Another object of the invention is to provide a reinforced refractory shape, which is particularly useful for the fabrication of open hearth roofs, walls and the like.

It is still another object of this invention to provide a metal reinforced basic refractory shape containing a minimum of oxidizable metal reinforcing-structure, the overall combination of which provides increased refractoriness, controlled expansion characteristics, minimum heat loss by reason of lower overall thermal conductivity, maximum structural stability at high temperatures, and minimum tendency to be weakened by the loss of metal by melting when the furnace is exposed to reducing conditions.

It is yet another object of this invention to provide a metal reinforced basic refractory shape which has minimum effective cross sections of refractory material exposed to the furnace atmosphere.

Briefly, in one embodiment, a reinforced basic refractory shape, according to the concepts of this invention, is comprised of a 9 x 4 /2 x 2- /2" refractory brick and two, opposed, generally U-shaped oxidizable metal reinforcing pieces. The first of the reinforcing picees is rela tively small, and is of a generally U-shaped-channel cross sectional configuration. This smaller reinforcing piece is adapted to be co-rnolded with the refractory shape, and to substantially divide it into three equal sections of generally rectangular configurations along its 9" dimension. This smaller, generally U-shaped, reinforcing piece will have its web portion exposed substantially along a first of the 9 x 4 /2" faces of the refractory brick. The second reinforcing piece is adapted to encompass the other three 9" faces of the refractory brick, and to leave the fourth face-4n which the smaller insert is placed-in an open configuration.

A better understanding, other features and further objects and advantages of a reinforced basic refractory shape, according to the concepts of this invention, will be readily apparent to those skilled in the art from a study of the following detailed description with reference to the drawings. In these drawings:

FIG. 1 is a perspective view of a reinforced basic refractory shape, according to the concepts of this invention;

FIG. 2 is a sectional view along the line 2-2 of the refractory shape of FIG. 1;

FIG. 3 is a bottom view of a row of refractory shapes of the type shown in FIG. 1, as they would be assembled in an open hearth roof;

FIG. 4 is a top view of an alternative construction for a reinforced refractory shape, according to the concepts of this invention.

In FIG. 1 there is shown a generally rectangular 9 x 4 /2 x 2 refractory brick it), having a downwardly-opening, generally U-shaped channel 11 co-molded therein. The oter surface of web portion 12 of channel 11 is exposed and lies in substantially the same plane as the 9 x 4 face 13 of the brick 19. The legs 14 and 15 of channel 11 extend downwardly into the body of brick 10, but terminate short of the opposite 9 brick face 16. It is important to note that all portions of the channel 11 are encapsulated within the body of brick 10, except for the outer face of web 12. Even the end edges 17 and 18 are contained in the brick it) behind its opposed respective end faces 1? and 2%).

A second reinforcing member 25, also of a generally U-shaped configuration, substantially entirely encompasses the other three 9" faces of brick it). The peripheral V edges, such as 26, 27, and 28 of the reinforcing member 25, desirably terminate short of the outer extremities or member 25 for better purchase (best seen in FIG. 2). The

cross sectional view of FIG. 2 is generally indicative of the spacing between the peripheral side edges of the reinforcing member 25, and the manner in which web 12 lies in substantially the same plane as face 13 of brick ltl. I t e In a refractory structure, such as in an open hearth roof or a furnace endwall, or a like portionof a metallurgical installation made of a plurality of brick, the

brick are installed soldier style" and in which sequential reinforced brick, of the type shown in FIG. 1, have their respective webs 12 abutting the web 40 of the outer reinforcing member 25 of the next brick. I have found that the outer face of the respective inner reinforcing members 12 fuses firmly to the next sequential outer web 40 of a subsequent reinforced brick, with sufficient strength as to maintain the separate brick substantially as a rigid entity in a serviceinstallation. This firm fusing is obtained with a minimum of oxidizable metal and,

because of the manner in which they are assembled with the brick, they do not lessen the refractoriness of the brick to any great degree.

It appears that embedding all of the smaller reinforcing channel 11, except for the outer face of the web 12, protects the metal of which the member 11 is fabricated from melting, and retards .metal loss. The larger and outer reinforcing member 25 which, as noted above, has its extremities within the peripheral bounds of brick 16, need be only sufficiently large as to assure good attachment between its leg portions and the 9 x 2 /2" faces of the brick 10, and its web of sufficient extent as to substantially contiguously overlie the extent of the outer face of Web 12 of an adjacent shape in a service installation.

Another'desirable feature of my structures is the ease of subsequent patching operations of refractory'structures in which they are used since they are easier to separate due to the lack of excess metal.

With this minimum amount of oxidizable metal in the reinforced refractory shape, much more uniform expansion 'is achieved upon heating, which expansion is much more easily controlled. The flush relationship, between the outer web of the smaller reinforcing member and one of the 9 x 4 /2" faces of the shapes, provides greatly increased and more effective fusing or welding between adjacent brick in a given row in a service installation, and prevents dropping out of the brick from such a row.

As noted above, the small insert 11 is co-rnolded'with the refractory shape 10. Preferably, the outer reinforcing member 25 is attached to the brick or shape It) by punching cars 30 into the 9 x 2 /2" faces of the shape. I have found that a -point pattern of the type shown in FIG. 1 is most satisfactory, in which an ear is punched substantially adjacent each of the four corners of the legs of the channel 25, and one substantially centrally of each of the legs. Of'course, other means of securing the outer members 25 to the brick 10 may be used, such as crimping the edges of members 25 tothe brick body, using adhesives, driving rivets or the like through the member 25 into the brick body, etc. Further, rivets, crimps, etc., may be formed in legs 14 and 15 of member 11, if so desired. V

The embodiment of FIG. 4 is particularly useful in open hearth roof installations. In FIG. 4, a brick 5%), having an outer reinforcing member 51 and an inner reinforcing member 52, is shown, which is similar in all respects to the brick of FIGS. 1 through 3 except for the

extended tabs

53 and 54. These

tabs

53 and 54 are formed integrally from the .web portions 55and 56 of the respective reinforcing

members

51 and 52, and extend beyond the cold face 56 of the brick 50. Each of the tabs53 and 54

has'an aperture

57 and 58, respectively, formed ther'ethrough, for purposes of mounting on roof reinforcing structure. In this arrangement, the not face 60 of-the brick 50 will be similar in all respects p to an endfac'e of the brick, as shown in FIG. 1, including encapsulation of all but the outer face 55 of member 52, and the preferable spacing of the peripheral edges of .member 51 from the extremities of a shape such as brick 50. Of course, if desired, a slot may be formed in the

tabs

53 and 54 instead of apertures, to provide for more easy replacement of brick in an open hearth roof.

While, in the foregoing discussion, agenerally rectangular shape has been used as an example, it is to be understood that the invention is equally applicable to' other refractory shapes such as keys, wedges, etc.

Having thus described my invention in detail, and with sufiicient particularity as to enable those skilled in the art to practice it, what I desire to have protected by Letters Patent, is set forth in the following claims.

I claim:

1. A reinforced refractory shape comprised of a refractory body having at least a pair of opposed faces, having only two oxidizable metal reinforcing channels carried by said body, each of said channels including a web portion between a pair of substantially parallel leg portions, a first of said channels being smaller and comolded through a first of said faces into the refractory body so as to divide said body into sections, said first channel being substantially entirely encapsulated within said refractory body with only the outer surface of the web of said first channel being exposed through said first face and lying in substantially the same plane'as said first face, the web of the second reinforcing channel being contiguous to the second of said opposed faces, the legs of the channels being oppositely directed, substantiallyparallel, and terminating short of an opposed face.

2. The shape of claim 1 in which the first channel divides the refractory body into three substantially equal sections.

3. The shape of claim 1 in which the end edges of the webs of the first and second channels terminate short of the peripheral extremities of the refractory body.

4. The shape of claim 1 in which each leg of the second channel has a plurality of tabs punched therefrom into the refractory body.

5. A reinforced refractory shape comprised of a refractory body having 'at least a pair of opposed faces, having only two oxidizable metal reinforcing channels, each of said channels including a web portion between a pair of substantially parallel leg portions, a first of said channels being smaller and co-molded through a first of said faces into the refractory body so as to divide said body into sections, said first channel being substantially entirely encapsulated within said refractory body with only the outer surface of the web of said first channel being ex 6. A reinforced refractory shape comprised of a re-' fractory body having at least a pair of opposed faces, having only two oxidizable metal reinforcing channels, each of said channels including a web portion between a pair of substantially parallel leg portions, a first of said channels being smaller and co-molded through a first of said faces into the refractory body so as to divide said body into sections, said first channel being substantially entirely encapsulated within said refractory body with only the outer surface of the web of said first channel being exposed through said first face and lying in substantially the same plane as said first face, the web of the second reinforcing channel being contiguous to the second of said opposed faces, the legs of the channels being oppositely directed, substantially parallel, and terminating short of an opposed face, a hanger device attached to the web of each of the channels and extending beyond the same surface of the refractory body.

7. The shape of claim 6 in which the hanger devices are substantially parallel plates having aligned apertures formed therethrough beyond the extremities of the refractory body.

8. A refractory structure comprised of a plurality of reinforced refractory shapes, each shape comprised of a refractory body having at least a pair of opposed faces, having only two oxidizable metal reinforcing channels carried by said body, each of said channels including a web portion between a pair of substantially parallel leg portions, a first of said channels being smaller and comolded through a first of said faces into the refractory body so as to divide said body into sections, said first channel being substantially entirely encapsulated within said refractory body with only the outer surface of the web of said first channel being exposed through said first face and lying in substantially the same plane as said first face, the web of the second reinforcing channel being contiguous to the second of said opposed faces, the legs of the channels being oppositely directed, substantially parallel, and terminating short of an opposed face, the plurality of shapes being arranged in soldier style and in parallel rows with the outer surface of the web of all but one of the smaller channels in each row in contiguous faceto-face relation with the outer surface of the web of a larger channel.

9. An open hearth roof comprised of a plurality of reinforced refractory shapes each shape comprised of a refractory body having at least a pair of opposed faces, having only two oxidizable metal reinforcing channels carried by said body, each of said channels including a web portion between a pair of substantially parallel leg portions, a first of said channels being smaller and comolded through a first of said faces into the refractory body so as to divide said body into sections, said first channel being substantially entirely encapsulated within said refractory body with only the outer surface of the web of said first channel being exposed through said first face and lying in substantially the same plane as said first face, the Web of the second reinforcing channel being contiguous to the second of said opposed faces, the legs of both of the channels being oppositely directed, substantially parallel, and terminating short of an opposed face, a hanger device attached to the web of each of the channels and extending beyond the same surface of the refractory body, the plurality of shapes being arranged in soldier style and in parallel rows with the outer surface of all but one of the smaller channels in each row in contiguous face-to-face relation with the outer surface of the web of a larger channel, and means cooperating With the hanger devices arranged to support them in position.

References Cited by the Examiner UNITED STATES PATENTS 2,465,170 3/49 Rochow 11099 2,736,187 2/56 Coffman et al. 2,846,963 8/58 Mason et al. 11099 2,853,872 9/58 Samuel.

3,012,525 12/61 Thomas et al. 11099 3,064,596 11/62 Heuer 11099 FOREIGN PATENTS 63 8,767 6/50 Great Britain.

JAMES W. WESTHAVER, Primary Examiner. FREDERICK KETTERER, Examiner.

Claims

9. AN OPEN HEARTH ROOF COMPRISED OF A PLURALITY OF REINFORCED REFRACTORY SHAPES EACH SHAPE COMPRISED OF A REFRACTORY BODY HAVING AT LEAST A PAIR OF OPPOSED FACES, HAVING ONLY TWO OXIDIZABLE METAL REINFORCING CHANNELS CARRIED BY SAID BODY, EACH OF SAID CHANNELS INCLUDING A WEB PORTION BETWEEN A PAIR OF SUBSTANTIALLY PARALLEL LEG PORTIONS, A FIRST OF SAID CHANNELS BEING SMALLER AND COMOLDED THROUGH A FIRST OF SAID FACES INTO THE REFRACTORY BODY SO AS TO DIVIDE SAID BODY INTO SECTIONS, SAID FIRST CHANNEL BEING SUBSTANTIALLY ENTIRELY ENCAPSULATED WITHIN SAID REFRACTORY BODY WITH ONLY THE OUTER SURFACE OF THE WEB OF SAID FIRST CHANNEL BEING EXPOSED THROUGH SAID FIRST FACE AND LYING IN SUBSTANTIALLY THE SAME PLANE AS SAID FIRST FACE, THE WEB OF THE SECOND REINFORCING CHANNEL BEING CONTIGUOUS TO THE SECOND OF SAID OPPOSED FACES, THE LEGS OF BOTH OF THE CHANNELS BEING OPPOSITELY DIRECTED, SUBSTANTIALLY PARALLEL, AND TERMINATING SHORT OF AN OPPOSED FACE, A HANGER DEVICE ATTACHED TO THE WEB OF EACH OF THE CHANNELS AND EXTENDING BEYOND THE SAME SURFACE OF THE REFRACTORY BODY, THE PLURALITY OF SHAPES BEING ARRANGED IN SOLDIER STYLE AND IN PARALLEL ROWS WITH THE OUTER SURFACE OF ALL BUT ONE OF THE SMALLER CHANNELS IN EACH ROW IN CONTIGUOUS FACE-TO-FACE RELATION WITH THE OUTER SURFACES OF THE WEB OF A LARGER CHANNEL, AND MEANS COOPERATING WITH THE HANGER DEVICES ARRANGED TO SUPPORT THEM IN POSITION.