Self-aligning fire brick assembly

Abstract

A structural configuration for wall and flue structures of refractory brick of improved strength that is self-aligning and resists distortion from thermal cycling and mechanical force

Description

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of, and is a continuation-in-part application of U.S. utility patent application Ser. No. 11/126,935 filed on May 11, 2005, which is entitled, Interlocking Insulating Firebrick, and is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to methods of assembling walls and linings of refractory brick; and more particularly, the present invention is directed toward a self-aligning construction and method which allows accurate and rapid assembly of walls and linings of refractory brick.

BACKGROUND OF THE INVENTION

Walls and linings constructed from refractory brick are utilized in numerous applications in furnaces, kilns and high temperature applications. Such walls and linings are typically assembled on-site with refractory brick of a tongue and groove configuration, laid down in courses. The refractory brick are typically about 4½ inches wide by 3 inches high and range in length from 4½ inches to about 15 inches and are of a 42% to 50% aluminum oxide composition; they are formed in a press having dies which yield the tongue shape on one face of the brick and the groove shape on the opposite side of the brick during the process of manufacture. The tongue and groove shapes are aligned along the length, aligned across the width of the brick, or aligned across both the length and width of the brick. The grooves formed in the brick are typically slightly larger than the tongues to assure the faces of the brick on one course will contact the faces of the brick on the subsequent course.

As an example in application, refractory brick is used in the construction of flue walls in carbon anode baking furnaces. Carbon anode baking furnaces are utilized to fire carbon anodes used in the Hall process of smelting aluminum.

The flue walls in such carbon anode baking furnaces separate the green carbon anode forms from the heating source yet conduct the heat from the heat source to the green carbon anode forms during the baking process. These flue walls are constructed with tongue and groove brick laid down in courses. As the brick are short in length relative to the total length of the flue walls, care must be taken to lay down a straight flue wall. Mortar is frequently utilized to adhere one course of brick to the next, or to level a course of brick to create a stable base for the next course. Additionally, in constructing flue walls of the prior art, tie brick are required to be interspersed within the flue walls to maintain the spacing between adjacent flue walls. Finally, it is often necessary to realign the flue walls in carbon anode baking furnaces; expansion and contraction from thermal cycling, and mechanical forces occasioned from loading and removing carbon anodes can distort the alignment of the flue walls.

Accordingly, it is an objective of the present invention to provide a self-aligning construction and method which allows accurate and rapidly assembly of walls and lining of refractory brick which resist distortion and are suitable for use in flue walls of carbon anode baking furnaces and other applications.

Other objects, advantages and applications of the present invention will be apparent to those skilled in the art from the following description of the invention.

SUMMARY OF THE INVENTION

The present invention provides a structural configuration for use in rapidly assembling walls and linings from refractory bricks that, aligns the bricks during assembly, results in a structure that resists distortion from thermal cycling or mechanical force, and eliminates or minimizes the need for tie brick and baffle brick to maintain the spacing of adjacent walls.

In constructing walls and linings of the present invention, each refractory brick is fabricated with a groove in its upper face and its lower face formed from a die. Although various sizes of bricks may be utilized, typical refractory bricks utilized with the present invention for walls and linings are about 4½ inches wide, 3 inches high, and 4½ to about 15 inches long. A wall or lining of the present invention is constructed of bricks laid down in courses. After a course is laid down, an insert of refractory material is laid into the upper groove of the course of bricks. The shape of the lower portion of the insert corresponds to the shape of the upper groove in the course of refractory bricks. A further course is then laid down with the grooves on the lower faces of the refractory brick engaging the upper portion of the insert, the shape of which corresponds to the grooves in the lower faces of the refractory bricks. Mortar may be utilized to fasten the bricks together, but is not essential. The insert may be of any suitable refractory material, shape, size and length, although ceramic tubing of a mullite composition in lengths up to 14 feet is preferred, as the material exhibits good strength and thermal shock resistance and is readily available.

In utilizing long length inserts that span the length of multiple refractory bricks, well aligned straight courses of refractory brick can be rapidly laid down without the need to check the alignment of the bricks during construction. Additionally, in a constructed wall or lining of the present invention, the wall or lining resists distortion resulting from thermal cycling and mechanical forces, as the inserts within the wall or lining span the length of multiple bricks; therefore the need to periodically straighten and realign these walls and linings is eliminated. Further, in applications where multiple walls are constructed a predetermined distance from one another, such as with the flue walls in carbon anode baking furnaces, the stability and self-aligning qualities imparted by the inserts in the present invention can minimize or eliminate the need for tie bricks to maintain the distance between walls. Still further, in constructing flue walls for carbon anode baking furnaces it is often desirable to assemble the bricks within a course with slight gaps between the bricks which allows the hydrocarbons driven from the carbon anodes to be sucked from the pit area into the flue chamber and burned away; in prior art wall constructions these gaps reduce the stability of alignment in the flue wall. In the present invention such gaps between the bricks can be readily incorporated without affecting the stability of the resulting wall as the length of the inserts incorporated within the wall maintain the stability of the wall.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a three-dimensional perspective view of a refractory brick of the present invention.

FIG. 2 is a three-dimensional exploded view illustrating the assembly of refractory bricks with a ceramic insert of the present invention.

FIG. 3 is a three-dimensional exploded view illustrating an alternate shape groove and insert in an assembly of refractory bricks and ceramic insert of the present invention.

FIG. 4 is a sectional perspective view of a representative portion of a constructed flue of a carbon anode baking furnace, illustrating the interlocking tongue and groove arrangement of refractory bricks from the prior art.

FIG. 5 is a sectional perspective view of a representative portion of a constructed flue of a carbon anode baking furnace, illustrating the interlocking arrangement of the refractory brick grooves and the inserts of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a typical refractory brick 10 of the present invention. The uppermost face of refractory brick 10 will be referred to as its top face 12; and the lowermost face of refractory brick 10 will be referred to as its bottom face 14. An upper groove 16 is fashioned in the top face 12 of refractory brick 10 extending from flat end face 18 to flat end face 20 and perpendicular to side faces 22 and 24. A lower groove 26 is fashioned in the bottom face 14 of refractory brick 10 extending from flat end face 18 to flat end face 20 and perpendicular to side faces 22 and 24.

FIGS. 2 and 3 illustrate how the interlocking components of the present invention are combined in the construction of a refractory wall or lining. A ceramic insert 28 is placed upon the top face 12 and within upper groove 16 of a first course of refractory bricks 10. When placed within upper groove 16, a ceramic insert 28 extends above top face 12 of the first course of refractory brick 10 and spans across at least two adjacent, and preferably more refractory bricks 10. Further refractory bricks 10 are then laid in a second course atop the refractory brick 10 of the first course with their lower grooves 26 engaging the ceramic insert 28 extending above the top face 12 of the first course of refractory brick 10. In constructed form, upper grove 16, in a refractory brick 10 of a first course, and lower groove 26, in a refractory brick 10 of a second course, form an aperture the internal dimensions of which conform to the external dimensions of ceramic insert 28.

Ceramic insert 28 may be chosen of solid or hollow material having a cavity formed by its inner surface 30; Refractory material may be placed within the cavity formed by the inner surface 30 of ceramic insert 28 to change its heat conductive properties. Although not necessary, it should be recognized that, the refractory bricks 10 of the present invention may be assembled together with refractory mortar or refractory fiber between joints.

In comparing FIGS. 2 and 3, it is illustrated that various shapes of grooves 16 and 26 and ceramic inserts 28 may be utilized in the present invention. In FIG. 2, upon assembly, upper grove 16, in a refractory brick 10 of a first course, and lower groove 26, in a refractory brick 10 of a second course, form an aperture that is circular in cross section and conforms to the external dimensions of ceramic insert 28 which is also circular in cross section. In FIG. 3, upon assembly, upper grove 16, in a refractory brick 10 of a first course, and lower groove 26, in a refractory brick 10 of a second course, form an aperture that is square in cross section and conforms to the external dimensions of ceramic insert 28 which is also square in cross section.

FIG. 4 illustrates a sectional view of a representative portion of a constructed flue 32 of a carbon anode baking furnace assembled from tongue and groove refractory brick 34 of the prior art. The prior art refractory brick has a top face 12, a bottom face 14, flat end faces 18 and 20 and side faces 22 and 24. A tongue 36 is formed on the top face 12 of each refractory brick 34 and a groove 38 is formed on the bottom face 14 of each refractory brick 34 as they are pressed out. The flue 32 is constructed from two walls of refractory brick 34 spaced apart from one another at a predetermined distance.

The walls of the flue 32 are constructed with numerous refractory brick 34 laid down in courses with the tongues 36 of each refractory brick 34 in a course engaging the grooves of the refractory brick 34 directly above them in the next successive course. With these prior art refractory brick 34, the tongues 36 are formed slightly smaller than the corresponding grooves 38 so that the top faces 12 of refractory brick 34 are certain to contact the bottom faces 14 of refractory brick 34 in a successive course.

In constructing a flue 32 for a carbon anode baking furnace from refractory brick 34 of the prior art, although it reduces the stability of the walls in the flue 32, adjacent refractory bricks 34 are frequently arranged with intentional gaps 42 provided between the flat end face 20 of refractory brick 34 and flat end face 18 of an adjacent refractory brick 34 to allow hydrocarbons driven from a carbon anode being baked to be sucked into the flue 32 and burned away.

As the tongue 36 of a given refractory brick 34 from the prior art can only engage grooves 38 of refractory bricks 34 directly above it, and as a wall of flue 32 is many refractory bricks 34 in length, maintaining the alignment of a wall and the separation between walls of a flue 32 presents difficulty. To address the problem of maintaining the separation between walls of a flue 32, tie bricks 40 are incorporated within and interspersed throughout the flue 32, mechanically joining the two walls of the flue 32, by interlocking with tongues 36 and the grooves 38 of refractory brick in both walls of the flue 32. The tie bricks 40 have top faces 12, bottom faces 14, flat end faces 18 and 20 and side faces 22 and 24. Tongues 36, corresponding to each wall of the flue 32, are formed on the top face 12 of each tie brick 40, and grooves 38, corresponding to each wall of the flue 32, are formed on the bottom face 14 of each tie brick 40 as they are pressed out.

FIG. 5 illustrates a sectional view of a representative portion of a constructed flue 32 of a carbon anode baking furnace assembled with refractory brick 10 and ceramic inserts 28 of the present invention. As previously described in connection to FIGS. 2 and 3, the walls of the flue 32 are constructed with numerous refractory brick 10 having upper grooves 16 and lower grooves 26 laid down in courses with ceramic inserts 28 engaging and aligning refractory brick 10 of a first course with refractory brick 10 of a subsequent course.

In constructing a flue 32 for a carbon anode baking furnace with refractory brick 10 and ceramic inserts 28 of the present invention, adjacent refractory bricks 10 may be arranged with intentional gaps 42 provided between the flat end face 20 of a refractory brick 10 and flat end face 18 of an adjacent refractory brick 10 to allow hydrocarbons driven from a carbon anode being baked to be sucked into the flue 32 and burned away. Since a ceramic insert 28 typically, spans the length of many refractory bricks 10, the gaps 42 may be incorporated in the wall without any significant decrease in the stability and alignment of the wall.

In the present invention, despite the fact that ceramic inserts 28, spanning the length of multiple refractory bricks 10 serve to maintain a predetermined separation between walls of a flue 32, tie bricks 44 may also be incorporated within and interspersed throughout the flue 32, to mechanically join the two walls of the flue 32 together.

Tie bricks 44 when utilized in the present invention, have top faces 12, bottom faces 14, flat end faces 18 and 20 and side faces 22 and 24. upper grooves 16 corresponding to each wall of the flue 32 are formed on the top face 12 of each tie brick 40 and lower grooves 26 corresponding to each wall of the flue 32 are formed on the bottom face 14 of each tie brick 40 as they are pressed out. As courses of refractory brick 10 are laid out in the two walls of a flue 32 at the same height, a tie brick 44 is laid out spanning the distance between the two walls with one lower groove 26 of tie brick 44 engaging a ceramic insert 28 of one wall, and the other lower groove 26 of tie brick 44 engaging a ceramic insert 28 of the other wall; as a subsequent course of brick 10 is laid down on each wall, upper groves 16 of tie bricks 44 engage ceramic inserts 28 of each wall in similar fashion.

Although the detailed description of the drawings is directed toward illustrating the above described preferred embodiments, the present invention is not limited to such embodiments, as variations and modifications may be made without departing from the scope of the present invention as claimed herein.

Claims

1. A refractory wall structure comprising a number of refractory bricks,

said refractory bricks being arranged in a number of courses, said refractory bricks having, opposed top and bottom faces, opposed end faces, and opposed side faces, when disposed in a refractory wall structure;

said top face having a top groove extending between said end faces;

said bottom face having a bottom groove extending between said end faces; and

a number of inserts placed within apertures formed where said top grooves of refractory bricks in a course, and said bottom grooves of refractory bricks in a next upper course are aligned with and face each other,

with each insert spanning a length greater than the length of one said refractory brick from end face to end face, and therefore engaging multiple refractory bricks within said course of refractory bricks and engaging multiple refractory bricks within said next upper course of refractory bricks.

2. A refractory wall structure as recited in claim 1 wherein at least two adjacent refractory bricks within said course of said refractory bricks are arranged with a gap between their adjacent end faces.

3. A refractory wall structure as recited in claim 2 wherein each said gap between said adjacent refractory bricks within said course, is spanned by one said insert engaging the top grooves of both said adjacent refractory bricks, and is spanned by another said insert engaging the bottom grooves of both said adjacent refractory bricks.

4. A flue structure comprising a number of refractory walls,

said refractory walls constructed a set distance apart and creating a flue space between them,

each said refractory wall comprising a number of refractory bricks;

said refractory bricks being arranged in a number of courses,

said refractory bricks having, opposed top and bottom faces, opposed end faces, and opposed side faces, when disposed in a refractory wall;

said top face having a top groove extending between said end faces;

said bottom face having a bottom groove extending between said end faces; and

a number of inserts placed within apertures formed where said top grooves of refractory bricks in a course, and said bottom grooves of refractory bricks in a next upper course are aligned with and face each other; with

each insert spanning a length greater than the length of one said refractory brick from end face to end face, and therefore engaging multiple refractory bricks within said course of refractory bricks and engaging multiple refractory bricks within said next upper course of refractory bricks.

5. A refractory flue structure as recited in claim 4 wherein within said refractory walls, at least two adjacent refractory bricks within said course of said refractory bricks are arranged with a gap between their adjacent end faces.

6. A refractory flue structure as recited in claim 5 wherein within said refractory walls, each said gap between said adjacent refractory bricks within said course, is spanned by one said insert engaging the top grooves of both said adjacent refractory bricks, and is spanned by another said insert engaging the bottom grooves of both said adjacent refractory bricks.

7. A refractory flue structure as recited in claims 4-6 further comprising a number of tie bricks;

said tie bricks having, opposed top and bottom faces, opposed end faces, and opposed side faces,

said top face of said tie brick having a first top groove extending between its said end faces near its first said side face,

said top face of said tie brick having a second top groove extending between its said end faces near its second said side face,

said bottom face of said tie brick having a first bottom groove extending between its said end faces near its first said side face, and

said bottom face of said tie brick having a second bottom groove extending between its said end faces near its second said side face,

said tie bricks spanning said flue space between said refractory walls and incorporated within a said course of said refractory bricks within each said refractory wall, whereby said first top groove and said first bottom groove of said tie brick function as said top groove and said bottom groove in substitution for said refractory brick in a first said refractory wall, and said second top groove and said second bottom groove of said tie brick function as said top groove and said bottom groove in substitution for said refractory brick in a second said refractory wall.