US3606722A - Refractory wall - Google Patents

Abstract

A REFRACTORY WALL IS CONSTRUCTED FROM A PLURALITY OF PLASTIC BLOCKS LAID INTO MULTIPLE COURSES. MOST OF THE BLOCKS ARE FORMED ENTIRELY FROM A PLASTIC REFRACTORY MATERIAL, WHILE THE REMAINING BLOCKS ARE FORMED FROM THE SAME PLASTIC MATERIAL BUT HAVE NON-DEFORMABLE ANCHOR CORES EMBEDDED IN THEM. EACH ANCHOR CORE IS CREATED FROM A REFRACTORY MATERIAL WHICH DOES NOT IMPAIR THE REFRACTORINESS OF THE PLASTIC REFRACTORY MATERIAL.

Description

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Filed April 2s. 1969 sept. 21V, 1911 FIGA I #dnt/75.

United AStates Patent @lice 3,606,722 REFRACTORY WALL William D. Fitzpatrick, Mexico, Mo., assignor to A. P. Green Refractories Co., Mexico, M0. Filed Apr. 23, 1969, Ser. No. 818,659 Int. Cl. E04b 1/76; E04g 21/14 U.S. Cl. 52-747 3 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION This invention relates in general to refractory walls, and more particularly to lblocks and a method for anchoring such Walls.

Refractory walls constructed from blocks or slabs of plastic refractory material are superior to conventional brick refractory walls in many applications. In the first place, the individual plastic slabs or blocks, once the furnace is fired, form a -monolithic wall construction, and this eliminates the problems associated with mortar joints. The monolithic wall constructions, furthermore, provide better insulation, have lower permeability, and can withstand greater thermal shock than brick walls of the same composition. Moreover, the plastic blocks or slabs may be molded to conform to contours peculiar to a particular furnace and, consequently, the high cost of securing special brick shapes is eliminated.

Currently, it is common practice to construct these monolithic walls from relatively small plastic slabs measuring 2" x l8 x 141/2. These slabs are laid into tiers or courses and are rammed into place, preferably with pneumatic hammers, although a mallet will suice. This ramming or pounding seats them tightly against one another and shapes them into conforming with the configuration of the furnace. In large refractory walls some of the slabs are rammed or pounded around fired refractory hangers which are attached to the metal binding or other permanent structural portions of the wall.

To reduce the cost and time required to lay relatively small plastic slabs into large monoliths, larger plastic blocks measuring 18" x 9" x 6" were developed, but these larger -blocks are difficult to anchor in place. One method of anchoring these larger blocks involves pounding some of the blocks around steel chains attached to the metal binding of the walls. The chains, however, react with the refractory material at high temperatures and impair the refractoriness of that material.

SUMMARY OF THE INVENTION `One of the principal objects of the present invention is to provide a refractory wall formedl from relatively large plastic refractory blocks, some of which have anchoring devices embedded in them. Another object is to provide refractory blocks with self-contained refractory anchoring cores which do not adversely affect the refractoriness of the blocks. A further object is to provide anchoring blocks of the type stated which are easily connected with complementary anchoring devices for holding the wall in place.

3,606,722 Patented Sept. 2l, 1971 Still another object is to provide an anchoring block which is simple in construction, and economical to manufacture. These and other objects and advantages will become apparent hereinafter.

The present invention resides in an anchoring block including a pliable portion formed from a plastic refractory material and an anchoring core embedded in the pliable portion. The anchoring core is formed from a non-deformable refractory material which does not impair the refractoriness of the plastic refractory material. The invention further includes a refractory wall having the foregoing anchoring blocks interspersed among plastic refractory blocks formed entirely from the same plastic refractory material. The invention also consists in the parts and in the arrangements and combinations of parts hereinafter described and claimed.

DESCRIPTION OF THE DRAWINGS In the accompanying drawings which form part of the DETAILED DESCRIPTION Referring now in detail to the drawings, 2 designates a refractory wall including a steel outer shell 4 lined with a backing material 6. Against the inwardly presented surface of the backing material `6 an inner series 8 of plastic refractory blocks 10 is laid, and the blocks 10 are comparatively large and have a rather stiif yet plastic constituency. One type of typical block 14 suitable for refractory walls of most furnace constructions measures 18 x 9l x 6". The blocks 10 in the series 8 are oriented such that their longitudinal axes are parallel to the shell 4, or in other words, their side faces facewise abut the backing material 6. Another or outer series 12 of blocks 10 is set against the iirst series 8, only the blocks 10 in this series 12 are oriented such that their longitudinal axes are perpendicular to the plane of the wall 2. Thus, one of the end faces of each block 10 in the series 12 facewise abuts one of the side faces of a block 10 in the series 8, while the opposite end faces of the blocks 10 in the series 12 form the interior face of the refractory wall 2. The blocks 10 are preferably cut from an extended length of plastic refractory material which has been formed to the proper cross-sectional configuration in an extrusion process and hence the blocks 10 are homogeneous throughout.

Interspersed among the blocks 10 in the series 12 are anchoring blocks 14 which have the same configuration and external dimensions as the blocks 10. Each anchoring block 14, however, is composite in composition, consisting of a red refractory core 16 embedded within a pliable portion 18 formed from the same plastic refractory material of =which the blocks 10 are composed. More specifically, the core 16 is rectangular in cross-sectional shape and extends the entire length of the block 14. It has one planar side face 20 which is exposed and is coplanar with the surface of the pliable portion 18 on each side of it. The three remaining sides of the core 16 are formed by undulated surfaces 22, and these surfaces 22 are covered by the pliable portion 18 within the interior of the block 14. Thus, three sides of the block 14 are formed entirely from the plastic material, while the fourth side is formed in part of the core 16. The undulated surfaces 22 prevent the core 16 from slipping longitudinally relative to the pliable portion 18.

At its one end the core 16 is provided with an anchor socket 24 (FIGS. 2 and 3) which opens outwardly through the adjacent end face as well as the side face 20 on the core 16. In particular, the anchor socket 24 is defined by a pair of side walls 26 which converge inwardly toward a throat area 28 and intersect the exposed planar side face 20 at a V-shaped margin. Beyond the throat area 28, the side walls 26 flare outwardly again in the formation of a retention pocket 30. The socket 24 does not extend entirely through the core 16, but instead terminates at a shoulder 32 (FIG. 2) within the interior of the core 16. Beneath the socket 24 a shallow recess 34 is located between the walls 26 so that the end margin of the shoulder 32 is set slightly inwardly from the end face block 14.

The refractory core 16 is preferably molded from a super duty iireclay product which is subsequently fired so that the fireclay sets into a rigid non-deformable shape. The fireclay should be compatible with the plastic refractory material from which the blocks 10 and pliable portions 18 are formed, or in other words, it should not react with that plastic material in such a way that the refractoriness of the plastic material is adversely affected. After the core 16 is red, it is placed in a mold cavity having the configuration of the block 14. Thereafter, an extruded segment plastic refractory material havingr a volume equal to that of the plastic portion 18 is also placed into the mold cavity and, subsequently, the plastic material is engaged by a press and forced around the undulated surfaces 22 of the core 16. The end result is the anchoring block 14 consisting of the anchoring core 16 having the pliable portion 18 co-molded about it.

The two block series 8 and 12 of the wall 2 are anchored to the rigid shell 4 by means of hanger assemblies 35, each of which attaches to an anchoring core 16 in one of the blocks 14 so that the series 12 is, in effect, held in place by its anchoring blocks 14. Each hanger assembly 35 includes an anchor 36 (FIGS. 2 and 3) which conforms to the shape of and fits within the socket 24 in one of the anchoring cores 16. The anchor 36 rests upon the shoulder 32 and is completely contained within its respective socket 24, excepting a small portion thereof which extends beyond the end face of the core 16. The portion of the anchor 36 located within the pocket 30 consists of a pair of diverging legs 38 which spread beyond the throat area 28 and preclude withdrawal of the anchor 36 through the adjacent end face in a direction longitudinally of the block 14. The portion of the anchor 36 located between the side walls 26, on the other hand, is provided with an aperture 40, a portion of which is located beyond the outer margin of the shoulder 32 so that the shallow recess 34 is exposed through the aperture 40.

The hanger assembly 34 further includes a clip 42 having a hooked end portion 44 which extends downwardly through the aperture 40 of the anchor 36 and terminates within the shallow recess 34. The opposite end of the clip 42 is provided with a flange 46 through which an anchor bolt 48 passes, and the anchor bolt 48, in turn, extends through the backing material 6 as well as through a key slot 50 (FIG. 4) formed in the steel shell 4. Beyond the key slot 50, the bolt 48 is fitted with jam nuts 52 which when tightenedd raw the bolt 48, clip 42 and anchor 36 toward the shell 4. This, in turn, draws the anchoring blocks 14 toward and tightly against the series 8 of blocks A10. Limited vertical movement of the clip 42 and bolt 48 is afforded by the vertical disposition of the aperture 40 and the extended length of the hooked end portion 44 therein, as well as by the vertical orientation of the key slot 50 and, accordingly, it is desirable to drive the bolt 48 and clip 42 downwardly into the block 10 across which it extends. This is not difficult since the blocks 10 in the series 8 are formed from a plastic refractory material.

After the blocks 10 and 14 are laid into the two vertical series 8 and 12, they are rammed tightly together preferably by a pneumatic hammer operating against the exposed end faces of blocks 10 and 14 in the series 12. This ramming causes the side faces of adjacent blocks 10 and 14 to conform to one another and to similar conform to any peculiar configurations the wall 2 may possess.

When the furnace enclosed by the wall 2 is fired, the blocks 10 in both series tiers 8 and 12 and the pliable portions 18 of the blocks 14 harden into a monolithic lining which is held in place by the anchoring cores 16 and the hanger assemblies 35. Since the cores 16 are formed from a refractory material which is compatible with the plastic refractory material of the blocks 10 and pliable portions 18, they may be exposed to the elevated temperatures of the furnace interior and yet will not react with the plastic material. Thus, each core 16 may and does, in fact, extend the full length of its respective block 14 without impairing the refractoriness of the refractory material from which the pliable portion 18 of that block 14 and the adjoining blocks 10 are formed.

Example A plastic refractory block 10 was formulated from a mix having a drying shrinkage of 1.5% and a combined drying and firing change from mold size after heating to 2550 F. for five hours of 0.60% expansion. The plastic block 10 contained a moisture content of 13.5% and had a plastic deformability as expressed by its workablity index A.S.T.M. Standard Method C-l81-47, of 27%.

A refractory core 16 was formed from a fired super duty fireclay product having a configuration shown in FIGS. 2 and 3.

The plastic material for the pliable portion 18 of the anchoring block 14 was formed from the same material as the block 10 and was extruded as one segment having a volume equal to the finished volume of the block 14 less the volume of the refractory core 16. The extrusion was then placed in the press along with the refractory core 16 which was shifted to the desired position therein, and the two components were `co-molded by the press.

A refractory wall 2 was constructed from the block 10 and 14 so formed, and it displayed excellent refractory properties.

The characteristics of the plastic block 10 are the same as conventional blocks in the art, i.e., it is moldable at relatively low pressure and shows only small dimensional change on drying and firing. The core 16 is on the same order of refractoriness as the block 10 and has strength characteristic of fired fireclay brick. In other respects the compositions of the block 10 and the core 16 are not critical and may be varied depending on the use and envlronment.

The anchoring blocks 14 may also be used in a similar wall construction in which the series 8 is replaced with a castable refractory. More specifically, the series 12 is constructed from the blocks 10 and 14 and anchored to the shell 4 as shown in FIG. 2. Then the space between the tier 12 and the shell 4 is filled with a castable refractory compatible with the refractory blocks 10i and 14.

This invention is intended to cover all changes and modifications of the example of the invention herein chosen for purposes of the disclosure which donot constitute departures from the spirit and scope of the invention.

What is claimed is:

1. A method for forming a refractory wall adjacent to a permanent supporting structure; said method cornprising laying pliable blocks directly against each other and in facewise abutment so as to form tiers of blocks,

the blocks being formed entirely from a plastic refractory material so that they are homogeneous throughout; interspersing composite blocks among the homogeneous blocks such that the composite blocks facewise abut adjoining homegeneous blocks, each composite block including a pliable Aportion formed from a plastic refractory material and -a substantially non-deformable core erntbedded in the pliable portion; seating adjoining 'blocks tightly together; tying the cores of the composite blocks to the supporting structure; and heating the homogeneous and composite blocks to a temperature suicient to harden the plastic material thereof.

2. A method according to claim- 1 wherein the core of each composite block is a tired refractory material;

and wherein the composite blocks are formed by comolding the plastic refractory material about the core under pressure.

3. A method according to claim `1 and further characterized by ramming adjoining blocks tightly together.

References Cited UNITED STATES PATENTS 1,983,590 12/1934l Anderson 52-232 1,978,077 *10/ 1934 Doyle et al. 52-379 2,240,117 4/1941 Homolya 52-378X 2,657,651 11/ 1953 Forsyth `110--99 2,901,990 9/1959 Hutter 110-99 3,197,3'15 7/ 1965 Jacobs et al. 106--67 3,197,930 8/1965 Kimrnlinger et al. 52F378 3,295,280 1/ 1967 Kettner 52-378 FOREIGN PATENTS 927,382 5/1963 Great Britain 52f-6l2 15 ALFRED C. PERHAM, Primary Examiner US. Cl. X.R.

Sil- 509, 612; 264--274

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