US 3274742 A
Description (OCR text may contain errors)
Sept. 27, 1966 w. BVPAUL, JR, ETAL 3,274,742
REFRACTORY WALL CONSTRUCTION Filed Feb. '7, 1963 4 Sheets-Sheet 1 INV NTOR5 g g4 ,z Ah I Sept; 27, 1966 w. B. PAUL, JR., ETAL 3,274,742
REFRACTORY WALL CONSTRUCTION 4 Sheets-Sheet 2 Filed Feb. 7, 1963 l NV $2.5 5
Se t. 27, 1966 w. B. PAUL, JR., ETAL 3,274,742
REFRACTORY WALL CONSTRUCTION Filed Feb. 7, 1963 I 4 Sheets-Sheet 5 p 7, 1966 w. 5. PAUL, JR., ETAL 3,274,742
REFRACTORY WALL CONSTRUCTION Filed Feb. '7, 1963 4 Sheets-Sheet 4.
United States Patent 3,274,742 REFRACTORY WALL CONSTRUCTION Wortley B. Paul, Jr., Berwyn, Pa., and George C. Mayhew, Dearborn, Mich, assignors to General Refractories Company, Philadelphia, Pa., a corporation of Pennsylvania Filed Feb. 7, 1963, Ser. No. 256,922 3 Claims. ((31. 52-245) The present invention relates to refractory Walls which are inclined to the horizontal and to the vertical, to methods for assembling and constructing such refractory walls, and to refractory brick, particularly burned basic refractory brick, for use in such refractory walls.
A purpose of the invention is to reduce the danger to masons in installing inclined refractory walls of burned refractory brick, particularly conical refractory walls, and especially such walls in basic oxygen furnaces or L/D converters.
A further purpose is to reduce the cost of installation of inclined refractory walls of burned refractory brick, particularly conical refractory walls in basic refractory furnaces or L/D converters.
A further purpose is to provide a metallic projection on a burned refractory brick.
A further purpose is to eliminate the need for using retaining forms during the construction of such walls.
A further purpose is to avoid the harmful effect on refractory life due to corbelling.
A further purpose is to hold the course of a burned refractory brick of an inclined refractory wall during installation and before it has been keyed in place and also during service by providing a metallic projection at the cold end transverse to the length of the brick and extending downward behind the cold end of the refractory brick of the next lower course, desirably also providing a space at the cold end of the refractory brick of the next lower course to receive the metallic projection.
A further purpose is to mount the construction on skewbacks and to hold the first course above the skewbacks by metallic projections engaged behind the skewbacks.
Further purposes appear in the specification and in the claims.
In the drawings we have chosen to illustrate a few only of the numerous embodiments in which the 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 perspective of one embodiment of refractory brick according to the invention, suitably illustrating a key arch brick.
FIGURE 2 is a perspective of the brick of FIGURE 1 shown from the opposite side.
FIGURE 3 is a fragmentary enlarged section on the line 3-3 of FIGURE 1.
FIGURE 4 is a vertical axial section partly in phantom of a basic oxygen furnace or an L/D converter having a refractory wall according to the invention.
FIGURE 5 is an enlarged fragment of FIGURE 4 as indicated by the circle 5 on FIGURE 4.
FIGURE 6 is an enlarged fragmentary section on the line 66 of FIGURE 5.
FIGURE 7 is an enlarged elevation of the hot ends of the bricks of FIGURE 7, the view being in the position indicated by the line 77 of FIGURE 5 and exaggerated for convenience in illustration.
FIGURE 8 is an enlarged elevation of the outside of the wall of FIGURE 5, in the position indicated by the line 88, and exaggerated for ease in illustration.
FIGURE 9 is an enlarged fragmentary section on the line 9-9 of FIGURE 6.
FIGURE 10 is a view similar to FIGURE 8 but illustrating a different position of the metallic projections of the upper course with respect to the joints in the lower course.
FIGURE 11 is a perspective of a key arch skewback brick as shown in FIGURE 5.
FIGURE 12 is a perspective of a top course brick as shown in FIGURE 5.
FIGURE 13 is a perspective showing the metallic projection before insertion in the brick.
FIGURE 14 is a perspective of a brick showing the metallic projection inserted in a recess in the brick.
FIGURE 15 is a plan view of the metallic projection of FIGURE 14 before bending.
FIGURE 16 is an elevational view of the projection of FIGURE 15.
FIGURE 17 is a right end elevation of the projection of FIGURE 16.
FIGURE 18 is an enlarged fragmentary top plan view of the brick of FIGURE 13 showing the insert in the brick recess.
FIGURE 19 is a vertical section taken on the line 1919 of FIGURE 18.
Describing in illustration but not in limitation and referring to the drawings:
In refractory construction at the present time, there are a number of places where walls are used which are inclined both to the vertical and the horizontal. A very good example is the basic oxygen furnace which has such an inclined wall construction of generally conical form near the upper part.
It has been familiar practice to construct such inclined walls by using a corbelled construction, in which the in ner and outer surfaces are of saw-tooth contour consisting of a separate step for each course of brick, the courses themselves being laid horizontally and with overlap. This has the objection, however, that the refractory life is greatly reduced due to the increased surface exposed to the furnace interior. Where an attempt has been made in corbelled construction to render the inner surface flush by feather-edging the hot end, the sawtooth contour remains at the cold or outer end.
In this corbelled construction, the cold ends of the refractory lack structural stability when the portion of the lining becomes thin, so that the refractory wall has a greater tendency to collapse.
Efforts have been made in Europe, Canada and the United States to eliminate the corbell and produce a continuous inclined surface at the hot face of the wall by making the longitudinal axes of the brick perpendicular to the hot face of the wall. This has resulted in increased refractory life.
In one procedure for building such walls, it has been suggested that a form be used which holds the brick in place during construction. This is expensive and also dangerous, since the masons are subject to the possibility of serious injury if the form should break before the wall becomes self-supporting. This is also only applicable to a wall which is of closed contour and therefore would become self-supporting.
Efforts to construct many wall portions without a form are highly dangerous, since the slope often is greater than will permit a brick to support itslef in inclined position (limited to about 22 degrees).
The present invention is designed to permit the construction of refractory walls inclined both to the horizontal and the vertical at :any desired angle with smooth interior surfaces free from corbelling.
One of the great advantages of the present invention 3 is that it is not necessary to use forms but, on the other hand, the masons can work in safety.
Another great advantage of the invention is that the cost of installation in view of the subsequent lining performance obtained is so reduced that the overall refractory cost of a basic oxygen furnace or L/D converter can be reduced by as much as 20% In a copending application of Paul, Serial No. 222,289 for Refractory Wall Construction, Brick and Method, filed September 10, 1962, now abandoned and of common ownership herewith, a refractory brick and wall is set forth wherein each refractory brick of an upper course is provided with a metallic projection comolded with the brick at the cold end transverse to the length of the brick and this metallic projection is fitted behind the brick of the lower course. This is satisfactory for an unburned refractory brick, but where it is necessary to use a burned refractory brick, such as in the safety lining of a conical section of a basic oxygen furnace, the heat of burning destroys the metallic projection. By a burned refractory brick, it is meant a brick which is .first molded and then subjected to high temperatures before installation in a furnace lining.
In accordance with the present invention, each burned refractory brick of an upper course is provided with a metallic projection at the cold end transverse to the length of the brick which is installed on the brick subsequent to the burning operation. In one form of the invention, a metallic tab is fixed to the cold end of the brick so that a portion of the tab extends transversely beyond the cold end. In another form of the invention a recess is molded in the brick and a metallic tab is inserted in the recess subsequent to the burning of the brick and this metallic projection is fitted behind the brick of the lower course, which may be either a skew or another one of the brick just described.
While the invention is applicable to any desired form of inclined refractory wall, it will find its greatest advantage in an inclined refractory wall of conical or other closed configuration, especially of the type employed in a basic oxygen furnace or L/ D converter.
' The refractory in the present invention can be assembled completely without retaining forms, and at the same time the danger formerly encountered by the masons is no longer present.
Considering first the forms as shown in FIGURES 1 to 9, we there illustrate a basic oxygen furnace or L/D converter 20 having a metallic shell 21 which receives a more or less permanent refractory safety lining 22 suitably of burned magnesite refractory and a refractory lining proper 23.
For purposes of illustration, both the glued tab embodirnent of the invention and the metallic tab insert embodirnent will be shown applied to the refractory lining proper 23. However, it should be understood that either form may be used on either the safety lining or the working lining and the principles of the invention are equally applicable to both. Furthermore, in some instances, it may be preferable to use the glued embodiment on the safety lining and the insert embodiment on the working lining or vice versa.
It should be further understood that where reference is made to refractory bricks, these may be bricks of the safety lining or bricks of the working lining.
The refractory lining proper 23 comprises a bottom portion 24 which may be of any conventional character,
a cylindrical side wall portion 25 which likewise may be of any conventional character, and an inclined conical portion 26 which conforms to the present invention and rests upon the cylindrical side wall portion 25- The refractory may consist of 50% by weight of coarse dead burned magnesite particles suitably in the size range between 6 and 28 mesh per linear inch and 50% by weight of fine dead burned magnesite particles in the size range through 48 mesh per linear inch. Other combinations of particles of suitable size may be employed as desired.
The conical inclined Wall portion has a lower course of skews 27 which are best seen in FIGURES 5 and 11 and which are desirably key arch skews of a character which have not heretofore been used. Considering their cross section as shown in FIGURE 5, they consist of a hot end 28 which conforms to the slope of the inclined wall, a cold end 30 which is parallel to the hot end except for the recess to be described, and a lower cold end portion 31 which is horizontal in assembly, making an angle at 32. There is a horizontal bottom face 33 which rests on the top of the cylindrical wall portion 25 and there is an inclined top surface 34 which is at right angles to the inner inclined face 28 of the wall portion 26.
Unlike the usual skewback, however, the side faces which are not shown in FIGURE 5 but which are ShOtWIl in FIGURE 11 are peculiar, giving the key arch character to the skews. Like a skew brick, the side faces 35 are converging toward the interior of the furnaces so that the hot face is narrower than the cold face and they also are converging upwardly so that the top face 34 is narrower than the cold face of the skew.
These skews are put in to make a complete circle or other endless figure in plan view, if necessary fitting in a specially cut brick or applying mortar to complete a tight fit.
Each of the skews at the upper portion of its cold face 30 has a recess 36 parallel to the hot face 28 and wide enough in the direction toward the hot face to receive a metallic projection 37 to be described.
In some instances, it may be desirable to eliminate the recess 36, and in this case, spaces at the cold end of the skewbacks to receive the metallic projections are formed by applying a coating of mortar over part of the cold face.
Suitably when the course of skews has been completed, the next course of bricks 38 are applied. Since the course of bricks 38 above the skews resemble each of the other courses, except at the top, it will be sufiicient to describe one of these upper courses 38. Each of the bricks of this upper course 38 as shown at 40 has a hot end 41 which extends into the furnace in direct prolongation of the hot end of the wall 35 and has a cold end 42 which is in principle parallel to the hot end 41.
' Each' of the bricks 40 has a bottom surface 43 and a top surface 44 which are suitably parallel as shown. Each of the bricks 40'also has side surfaces 45, and as the bricks are key arch bricks in the preferred embodiment, the side surfaces 45 converge toward the hot end so that the cold end has a larger surface than the hot end. The bricks 40 also converge upwardly so that the upper surface 44 is smaller than the lower surface 43.
While the use of bricks of this particular character is preferred in the present embodiment, it will be understood that for many aspects of the invention, advantages will be obtained by simply using key brick or simply using arch brick or simply using :arch brick without necessarily using key arch brick.
The longitudinal extent of the brick, or the length, is from the cold end to the hot end. At the cold end, each of the bricks has extending transverse to its length or at right angles to its bottom surface 43 a metallic projection 37.
The projection 37 in one form consists of a flat metallic sheet which is attached to the cold end of the brick by a strong adhesive 39'. An :area 42' is left uncovered at the cold end of the brick so that a space between the brick and the safety lining can be formed on a lower formed in Z shape as shown in FIGURE 13. One leg 37 of the Z is intended to protrude transverse to the cold end of the brick as shown in FIGURE 14. Another leg 37 of the Z is intended to enter a recess 39 comol'ded in the brick. The recess is shown as a partial truncated inverted cone in shape, but it may be of cylindrical or other form.
The leg 37 has a flat portion 37 and rounded edges 37 curved to suitably fit the contour of recess 39 when slightly compressed. A web 37 is intended to lie along face 43 of the brick. The web 37 lies in a recess 43 in face 43 so that the top surface of the web 37 is flush with the face 43 as best seen in FIGURE 19. The projection 37 is suitably driven or otherwise inserted into recess 39 after the brick has been subjected to burning and before the brick is installed in the wall. Preferably inclined recesses 42' are InOllCiBd in the brick to receive portion 37 (from an upper course of brick as later explained.
The size of the steel sheet used in the projections 37 and 37 is to be determined by the size of the brick shape involved and can range in thickness between 16 gage to 22 gage as required.
In installing the course of brick 38, the metallic projection 37 is hooked into the recesses 36 of the skewbacks or the space formed by the mortar coating and the complete ring of the course 38 is preferably completed and keyed into place.
Subsequently courses then resemble the installation of the course 38, except that the metallic projections are engaged in the spaces 42' when using insert 37 or the spaces 46 fonrned by the previous course of bricks when using the adhesively applied projections 37, instead of recesses of the skewbacks. The spaces 46 are formed at portion 42 of the cold end of the brick 42 not occupied by the tab 37.
The topmost course 51 is of suitable shape to render the mouth of the furnace lining level with the mouth of the furnace shell. The brick 52 used in the topmost course 51 is shown in FIGURE 12. The brick has a lower inclined face 53 which conforms to and rests upon the lower course of bricks 38. The hot face 54 is flush with the inclined conical portion 26. The top face 55 is so disposed as to be level with the top of the shell when the brick is put in place. The face 56 is in a plane normal to the plane of the face 55. Face 56 is so disposed in order to provide the proper critical dimension across the mouth opening.
Opposed faces 57 and 58 are disposed at an angle toward one another compatible with the furnace diameter at that elevation. Outer face 60 conforms to the shell contour.
It will be evident that the location of the joints in the upper course with respect to the joints in the lower course will depend to some extent upon the preference of the installer. Thus, if desired, the joints can be staggered as shown in FIGURE 8, in which case the projections 37 of one brick will in some instances engage behind two bricks of the lower course. On the other hand, the joints can be in line as shown in FIGURE as preferred.
The principles of the invention are applicable regardless of the composition of the refractory bricks, and while burned basic magnesite refractories have been selected, it will be understood that other burned refractories, especially other burned basic refractories, may be used.
Although the embodiments of the invention have been illustrated on the refractory lining proper 23, it should be understood that the invention may be applied with equal results on the safety lining 22.
In view of our 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 benefits of our invention without copying the method and structure shown, and We, therefore, claim all such insofar as they fall within the reasonable spirit and scope of our claims.
Having thus described our invention what we claim as new and desire to secure by Letters Patent is:
I. An inclined conical refractory wall comprising burned refractory bricks laid in conical course, each brick having a hot end and a cold end with sides extending longitudinally between the ends, the hot end forming an inner inclined conical wall surface with a cold end being substantially parallel thereto, said wall including a lower course of bricks and an upper course of bricks resting directly on the lower course of bricks, each brick of an upper course having an aperture in the lower side of the brick and a metallic projection, the projection inciuding a tab extending downwardly from the cold end of the brick perpendicular to the lower side of the brick adapted to engage against the cold end of a brick of a lower course, a web extending inwardly therefrom along a recess in the lower side of the brick toward the hot end and a leg extending upwardly from the web parallel to the tab and resiliently wedged into the aperture in the lower side of the brick.
2. An inclined refractory wall according to claim 1, wherein the outer surface of the tab is flushed with the cold end surface of the brick, each brick additionally including a recess extending from the top of the cold end of the brick downwardly a part of the distance to the lower side of the brick, the recess adapted to receive the tab of the metallic projection of a brick of an upper course.
3. An inclined conical refractory wall according to claim 1, wherein the lowermost course of bricks are comprised of skewback bricks having a hot end conforming to the inclined conical wall surface, a lower side substantially horizontal at an upper side substantially perpendicular to the inclined wall surface and an uppermost course of bricks having a lower side substantially perpendicular to the inclined wall surface and an upper surface substantially horizontal.
References Cited by the Examiner UNITED STATES PATENTS 495,411 4/ 1893 Heatley 5 2-609 829,234 8/1906 Seipp 52704 1,648,363 11/1927 Reintjes -99 1,913,168 6/1933 Longenecker 110-99 2,319,065 5/ 1943 Karmanocky 110-99 2,695,257 11/ 1954 Castellani 161156 2,885,976 5/1959 McGill et 'al 110-99 2,915,893 12/1959 Wilkins 110-99 3,005,424 10/ 1961 Heuer 110-99 FOREIGN PATENTS 85,213 3/1958 Denmark. 638,767 6/1950 Great Britain.
FRANK L. ABBOTT, Primary Examiner.
HENRY C. SUTHERLAND, Examiner.
J. L. RIDGILL, Assistant Examiner.