US2291938A - Furnace lining - Google Patents

Description

Al1g- 4 1942 A. B. AGNEW 2,291,938

FURNACE LINING Filed May 9, 1940 INVENTOR. BY

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Patented Aug. 4, 1942 UNITED STATES PATENT Y OFFICE FURNACE LINING Albert B. Agnew, Indiana, Pa., assignor toHarbison-Walker Refractor-ies Company, Pittsburgh, Pa., a corporation of Pennsylvania Application May 9, 194,0, Serial No. 334,197

4 Claims.

. vision is made to prevent it. ,Various means have Cil been proposed for breaking such joints, but it is 'relieved that none is as satisfactory as that dis- .iosed in this specification. The reasons for wanting to have all vertical joints broken are well known in the art and need not be repeated here- 1n.

It is among the objects of this invention to provide a furnace lining of the character referred to above in which all of the vertical joints are broken, in which the breaking of vertical joints is accomplished in a simple and inexpensive manner, in which the sizes and shapes of the bricks and the cost of laying them are not lincreased materially, in which the vertical joints are inclined relative to the horizontal, in which the number of horizontal joints is reduced, and in which the bricks more successfully resist the strains placed upon them by weight and thermal changes.

In accordance with this invention a furnace is lined with refractory bricks in the usual manner: that is, the bricks are laid in superimposed courses with two or more adjoining rings of bricks in each course. All of vthe vertical joints between the bricks in any given ring are inclined vertically in the same direction, While all of the Vertical joints between the bricks in the adjoining ring, in the same course are inclined fore. This decreases the number of horizontal joints and materially reduces the likelihood of the bricks being broken by weight or by unequal expansion vertically.

'I'he preferred embodiment of the invention is illustrated in the accompanying drawing in which Fig. 1 is a fragmentary view of a blast furnace broken away to show a portion of my lrefractory lining in section; Fig. 2 is an enlarged fragmentary plan. .view of two superimposed courses of briks forming the lining; and Fig. 3 is a vertical section taken substantially on the line III-III of Fig. 2.

Referring to the drawing, a blast furnace I is provided with a lining formed from refractory bricks laid in superimposed courses. Each course is formed from a plurality of concentric rings of bricks. In the lining illustrated every other course 2 consists of two rings of bricks 3 while the intermediate courses 4 consist of three rings of bricks 5. The bricks are of such length that .three of the shorter are equivalent to two of the longer.

In accordance withthis invention the bricks are not rectangular in vertical cross section, as is the usual form, but are rhombic. That is,` as

shown inFg. 3, the upper and lower surfaces of each brick are parallel and horizontal, but the side faces are inclined vertically in the same di-y rection. Most, if not all, of the bricks, depending upon the shape of the lining and its diameter, are wedge shape in horizontal section. vAs will be seen in Fig. 2, the so-called vertical joints 1 between thebricks in the inner ring of the tworing course-2 fall at various points relative to the adjacent vertical joints 8 between the bricks in the outer ring in the same course, due to there necessarily being more vbricks in the outer ring.

vertically in the opposite direction. Thus, wherv ever vertical joints meet at the junction of the two rings they do not coincide throughout their lengths but cross each other, whereby the joints are broken.

Although the joints between the side faces of the bricks are referred to herein as vertical, as is customary, it will be understood that due to their inclination they are not truly vertical. brick are horizontal and are connected by vertically inclined side faces, resulting in the bricks being rhombic in vertical transverse section. Preferably, the bricks are laid with their greater width extending vertically rather than horizon,- tally as has been the general practice hereto- The upper and lower surfaces of each Some of these joints appear to be in line,` but actually they are not. This is because the inner ring is laid with bricks that are inclined 'to the Y right while the outer'rin'g is laid .with bricks inclined to theleft. Consequently, vertical joints in the two rin-gsv that might otherwise coincide cross each other so that they'meet at only a pointw The same thing is true of the vertical joints infall of the other courseafwhether vformed from two rings or more. It will thus be seenshat all of the bricks in a course may be the-same size, the only difference being thatv thosein one ring are right-hldfjbreksand those in the adjoin -are left-hand" lbricks.` 'I 'his-condition automatically takes care of breaking theavertical joints between the rings when thebrielis are laid. As shown yin Fig. 3, the Abricks arejaidwitlr 'joints between the courses is cut in half.

vof the brick and in the joints.

their greater width extending vertically. When this width is twice as great as the lesser width, as is usually practiced, the number of horizontal This leaves only half as many horizontal joints exposed to the scouring effect of the hot gases and charges in the furnace. VAlthough in such a case the number of vertical joints is doubled, as these joints are inclined and as the courses are laid so that an inner ring of left-hand bricks adjoins inner rings of right-hand bricks above and below, the inner surface of the lining is provided with zig-zag vertical joints on which the upwardly moving gases and downwardly moving furnace charges can not have as damaging eect as on truly vertical joints.

Another advantage of laying the bricks in this manner is that their stronger section is exposed to vertical stresses so that there is little likelihood of their being broken by unequal ther- `mal expansion vertically or by the weight of the liningon bricks having unequal horizontal joints directly below them which do not give them uniform support throughout the area of their lower surfaces. This increased resistance to breakage is aided by the inclination of the bricks which causes those in any ringto partially overlap,

whereby each brick is supported against vertical pressure by an adjoining brick.

A still further advantage of having the long width of the bricks extend vertically arises when the inner end of a brick in an outer ring straddles the vertical joint between two bricks in the adjoining inner ring. Due to the .outer brick being narrower than heretofore, less clearance is required between its vertical edges and the adjacent ends of the innerA bricks. 'I'his means thatl the joint between the rings at such a point can be narrower than heretofore. One of the reasons that it is desirable to have as small and tight joints as possible is that the normal blast furnace atmosphere during operation contains a high percentage of carbon monoxide. This gas tendsI to penetrate the furnace lining and to decompose and deposit carbon within the porcs The carbon deposits grow with a tremendous expanding force which'has been known to disrupt the brick and to disintegrate them. Narrow tight joints help prevent this penetration carbonv monoxide.

According to the provisions of the patent statutes, I have explained the principle and construction. of my invention and have illustrated and `described what I now consider to represent its best embodiments. However, I desire to have it understood that, within thescope of the aD- pended claims, the invention may be practiced tically in the opposite direction, whereby said joints that meet at the junction of said two rings cross each other to obstruct outward flow of gases through said joints.

2. A side wall brick lining for furnaces, comprising a, plurality of superimposed courses each formed from a plurality of abutting rings of bricks, the verticallyA extending joints between the side faces of the bricks in each of said rings being oppositely inclined with respect to like joints between the bricks in the abutting ring in the same course, whereby said joints that meet at the junction of said two rings cross each other for the purpose of obstructing outward flow of gases through said joints.

3. A side wall brick liningfor furnaces, comprising a plurality of superimposed courses each formed from a plurality of abutting rings of bricks whose vertical height is greater than their horizontal width, the bricks in each ring being independent of those in the other rings, and the vertically extending joints between the side faces of the bricks in each of said rings being oppositely inclined with respect to like joints between the bricks in the -abutting ring in the same course, whereby said joints that meet at the junction ef said two rings cross each other to obstruct outward flow of gases through said joints.

4. A side wall brick lining for furnaces, comprising a plurality of superimposed courses each formed from a plurality of abutting rings of bricks with the bricks in each ring independent of those in the other rings,.the vertically extending joints between the side faces of the bricks in each of said rings being oppositely inclined with respect to like joints between the bricks in the abutting ring in the same course, whereby said joints that meet at the junction of said two rings cross each other to obstruct outward flow of gases through said joints, and said joints in each inner ring being inclined in a direction opposite to that of like joints in the adjoining inner rings above and below.

ALBERT B. AGNEW

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