US2179666A - Checkerwork structure - Google Patents

Description

Nov. 14, 1939. A. G. M KEE CHECKERWQRK STRUCTURE :5 Shets-Sheet 1 INVENT OR. AFT/1UP 6- MYFIE WW ATTORNEYS Filed Aug. 5, 1938 Nov. 14, 1939. A. G. MCKEE 2.179.666

CHECKERWORK STRUCTURE Filed Aug. 5, 1938 3 Sheets-Sheet 3 INVENTOR. A 7877107? 6. M KEE A TTORNEYS Patented Nov. 14, 1939 ram OFFICE 10 Claims.

This invention relates generally to apparatus for the transfer of heat between air or other gases and solid heat absorbing bodies and more particularly to an improved checker brickwork construction for blast furnace hot blast stoves or the like.

In recent years there has been a constant demand for increased capacity in blast furnace hot blast stoves and the cost of constructing the checker brickwork of such stoves has increased very materially due to the attempts to increase the heating surface and volume of the fire brick checkerwork in the stove. This increase in cost has been largely due to the fact that, in attempting to meet the demands for increased efficiency and capacity, complicated and extremely costly forms of bricks have been utilized. In addition to the high cost, many of the present types of checker brick structures are so designed that the heating surfaces of the bricks are not well distributed with respect to the volume of brick behind the exposed surfaces. This results in inefficient use of the heat absorbing and retaining capacity of the bricks. The majority of the checkerwork constructions now employed are composed of a plurality of intersecting brick walls, the spaces between the walls forming the fines. In such structures the brick at the intersections is unavailable because there is no heating surface opposite or adjacent these dead corners. In my improved checkerwork flat rectangular columns of bricks are arranged with all surfaces exposed except at relatively small areas where spacing flanges or lugs contact the columns. With my long, flat columns the amount of useful heating surface and of brick volume per cubic foot of checker volume is very large.

It is among the objects of my present invention to provide a checker brick structure of the type described which is made up largely of standard shapes and sizes of fire brick which are relatively inexpensive, together with certain specially shaped spacing bricks which are of simple form and relatively inexpensive as compared to many of the complicated checker bricks now in use. Other objects of my invention are the provision of a checker brick structure in which a large percentage of the surface area of the bricks is exposed to contact with the gases in such a manner that very efficient heat transfer is effected; the provision of checker brick structure in which the bricks which define the fines through the structure are locked securely in place laterally while vertical expansion and contraction of the columns of bricks making up the structure is permitted; the provision of a checker brick structure in which the air or other gas is caused to pass over substantially all of the exposed surface of the bricks making up the structure; and the provision of a checker brick structure which may be economically installed and repaired and which will provide a large volume of firebrick in a given stove space together with a correspondingly large and effectively distributed area of exposed heating surface of the firebrick.

The above and other objects of my invention will appear from the following description of a preferred form thereof, reference being made to the accompanying drawings, in which- Figure 1 is an illustrative horizontal cross-section through a blast furnace hot blast stove showing the general arrangement of my checker structure in the stove.

Figure 2 is a detached perspective view of a portion of one embodiment of my improved checker brickwork, parts being broken away for purposes of clearer illustration.

Figure 3 is an elevational view of a detached section of the checkerwork structure of Figure 2 showing the bottom row of bricks and illustrating the manner in which the building up of the structure is started and alsoshowing the sinuous paths of the gases.

Figure l'is a vertical cross-sectional view taken substantially on line 5-4 of Figures 2 and 3.

Figure 5 is a horizontal cross-sectional view taken on line 5-5 of Figures 2 and 3.

Figure 6 is a plan view of the top of a section of checker brickwork shown in Figures 2, 3, 4 and 5.

Figure 7 is a view generally similar to Figure 2 but illustrating a modified arrangement of the bricks making up the checkerwork.

Figure 8 is a horizontal cross-sectional view taken on line 88 of Figure 7.

The hot blast stove I may be of any suitable type and includes, in the usual manner, a combustion chamber 2 and a heating or checker chamber 3 which is filled with the checker brickwork t. The checkerwork is shown in only a portion of the heating chamber 3 for purposes of simplicity of illustration and it will be understood that the entire chamber 3 will be filled with checker bricks. It will also be understood by those skilled in the art that although I have particularly referred to the use of my checker-brick structure in connection with blast furnace hot blast stoves, it may also advantageously be used in numerous other installations where efficient heat transfer is required.

Figure 2 illustrates in perspective a portion of a checkerwork structure built up in accordance with my invention. In this embodiment standard firebricks 2 x 6 x 13 are arranged in vertical columns, each of such standard brick in each column being separated by a spacer brick of special design. These bricks are of oblong form in horizontal cross-section, the term oblong being understood to mean, as used herein, a rectangle having adjacent sides unequal. Thus, in Figure 2, the column indicated generally at A is made up of standard 2 x 6" x 13 oblong cross-section firebricks arranged on end and spaced by the spacer bricks 5. Adjoining the column A are the columns B, C and D, the column B being made up of standard bricks 1 and spacing bricks 8, the column C being made up of standard bricks 9 and spacing bricks Ill, and the column D being made up of standard bricks II and spacing bricks I2. As will be later described, when starting to build up the structure the vertical columns are so supported that the standard brick in adjacent rows of columns will be staggered. In this manner the special spacing and interlocking bricks 6, 8, H], II,

etc., will be vertically located at the center of the standard bricks of adjacent rows and each standard brick will be held in position by engagement at the central portion of each vertical edge with a spacing brick of an adjacent column.

InFigure 2 additionalcolumns E, F, G, H and J are illustrated and it Will be observed that the columns B and E constitute what may be termed the first row of columns of the checker structure, the columns A, C and F lie in the second row, the columns J, D and G lie in the third row and the column H lies in the fourth row. The columns of adjacent rows are offset or staggered relative to each other and this disposition of the columns making up the structure may be referred to as checkerwise arrangement. Of course, in building up checker brick structure the entire space will be filled and all of the columns will be continued upwardly to the top of the available space. The special spacing bricks 6, 8, l0, etc., when used with standard 2 X 6 x 13 bricks will preferably have outside dimensions of 2 x 6" x 5" and each spacing brick has laterally extending spacing rib or lug members [3 and [4 (see spacer brick 8 of Figure 2) and in each corner formed between the ribs or lugs l3 and I4 and the main body of the brick a spacing flange member I 5 is provided (which may be curved as shown in Figures2 and 3 or straight as shown in Figure '7). As is seen in Figure 2 each vertical corner of each standard brick engages the face of the flange [5 and the vertical side edge of the projection I3 or M of a spacing brick in each of four adjacent columns and lateral movement of the standard bricks is thus prevented without interferring with vertical expansion or contraction of the columns.

In the form of my bricks described and illustrated in Figures 2, 3, 4 and 5, the ribs l3 and I4 extend approximately 1" out from the sides of the body of the spacer bricks and the flanges l5 extend approximately /2" outwardly from the sides of the spacer bricks. Thus, when the bricks are arranged as shown in Figure 2, the rows of columns are definitely spaced approximately from each other by the flanges l5 and a plurality formed.

of verticaly extending flues indicated at [6 .is (Columns B and E are spaced from columns A, C and F, and columns A, C and F are spaced from columns J, D andG, etc.) The columns of each row are spaced a distance equal to the width of the projections i3 and M, which in the structure described in 2", and thus the fiues [6 are 2" x 3 in cross-section except where the spacing bricks are located at which places the flue cross-section 2" x 1 This reduction in cross-sectional area achieves certain distinctly advantageous results which will be described later.

As the air or gas passes through the flues M5, for instance in a downward direction as indicated in Figure 4, it encounters, at regular intervals, the restricted areas noted above and indicated at R in Figures 3, 4 and 5. The unrestricted portions are seen clearly at W in Figure 4 where the flanges on the spacer bricks below the line on which the section is taken have been omitted for purposes of better illustration. The restricted areas R offer an additional resistance to the downward movement of the gas through the flues and cause the gas to spread out laterally through the narrow, A wide slots between the adjacent rows of columns into unrestricted portions of the adjacent flues H5. The sinuous or tortuous paths into which portions of the gas passing down each flue are diverted by the spaced restrictions R are seen in Figure 3. The gas is caused to pass over the full area of the exposed surfaces of the bricks making up the checker work structure and thus maximum heat exchange efilciency is obtained.

The restrictions R in the vertical fiues do not seriously interfere with the free passage of the gas through the checker structure because, although the vertical flue passages are restricted, where such restrictions occur narrow lateral passages are available through which the gas may pass into unrestricted portions of adjacent flues. Figure 6 and the flue shown at W in Figure 5 illustrate the cross-sectional area of the unrestricted portions of the lines and the transverse spaces between adjacent lines. The only portions of each standard brick and of each special spacer brick Which are not exposed to contact with the as are those small corner sections where the standard bricks engage the portions i3, i4 and I 5 of the spacer bricks and thus high heat transfer efficiency is obtained.

In starting the building up of a checker structure of the type illustrated in Figure 2 I prefer to use, the alternate rows of columns, short, base bricks II. A special spacer brick is placed immediately on top of each short, base brick I7 and, in the intermediate rows of columns, the bottom brick is a standard oblong cross-section brick as shown at I8 in Figure 3. The short bricks I! serve merely to stagger the first course of bricks so that each spacer brick will engage the central portion of a vertical corner of each of four adjacent standard bricks. In the example of Figures 2 to 5 the short bricks i1 are 2 x 6 x 4%,". If desired other means may be utilized for starting the staggered or offset arrangement of the standard bricks in the adjacent rows of columns.

In Figures 7 and 8 I have illustrated a modified ber of special bricks is reduced by building up" each vertical column of pairs of abutting standard bricks with special bricks interposed between successive pairs.

The arrangement is clearly shown in Figure 7 is reduced to which shows a fragmentary portion of a checker structure starting from the bottom or ground level thereof. The front row as illustrated comprises columns K and L, the next row includes columns M, N and O, and the third row is made up of columns P, Q, S and T. A portion of the top brick of the column 0 is broken away to show one of the special bricks of still another column which may be indicated by the reference letter U. The checkerwise arrangement of the columns is clearly seen in Figure 7.

In building up the structure the columns K, L, P, Q, S and T are started by standard 2 X 6" x 13 bricks i9. Special bricks 2i) are placed on top of the bricks i9 and then two standard bricks 2i and 22, best seen in column P, are placed on top of the special bricks 2E3. Another special brick 23 is disposed on top of each of the bricks 22 and the columns are continued up to the desired height with two abutting standard bricks between each two special bricks. In the intermediate rows of columns (M, N, O, U, etc.) special bricks it are placed on the base or ground level and are surmounted, in the lowest course only, by short, oblong bricks 25. These bricks are, in the illustrated arrangement, approximately 2 /2" x 6 x 11%". Each of these short bricks 25 is surmounted by a standard brick 26 which in turn carries another special brick 2i and from this point on the same arrangement of bricks as in the columns K, L, etc., is utilized, 1. e., two standard 2 2; 6 x 13 bricks between each pair of special bricks.

With the arrangement shown, and by starting the columns as described, the special bricks ill will break the joints between the short bricks 25 and standard bricks 2b. The special bricks 2i will break the joints between the standard bricks 2i and 22 of each column. In the complete checker work structure each joint between two standard bricks will be thus guided and supported by corner engagement with the four adjacent special bricks. The vertical spacing between courses of special bricks will be twice as great as that in the embodiment shown in Figure 2 and consequently there will be only half as many restricted portions R in the embodiment of Figure 7 as there are restricted portions R in the embodiment of Figure 2 for any given length of flue.

The special bricks shown in Figures '7 and 8 are modified slightly from those shown in the other views in that the projecting portions i3 have grooves it" formed therein and straight flanges it? are used instead of the curved fianges lb. The action of the fiue structure is substantially the same as that described above in connection with the form of my invention shown in Figure 2. The first cost of the installation of Figure 7 is somewhat less than that of Figure 2 because fewer special and more costly spacing bricks are required.

It will be observed from the above description of two preferred embodiments of my invention that my improved checker structure possesses the definite advantages of low first cost; a structural arrangement, the parts of which make a very stable and solid checker work structure while amply providing for necessary expansion and contraction; simplicity of construction; high heat exchange efficiency due to effectively exposing a very large percentage of the surface area of all of the bricks to the gases and eificient distribution of the gases through the openings in the checker structure due to my arrangement of flues having spaced restrictions and lateral slots interconnecting adjacent fines; and large volume of fire brick in a given space in which a greater amount of heat may be stored due to the thick bricks used, the exposure of nearly all of their available surfaces, and to the compact spacing of the bricks made possible by my improved construction.

As used herein and in the appended claims the words oblong and-rectangular are synonamous, meaning a plane rectangular figure having adjacent sides unequal. The term smooth as used herein refers to my standard bricks and is intended to mean that the bricks are free from projecting lugs, arms, etc. The term is not intended to constitute a limitation as to the surface cond tion of the bricks themselves which might be relatively smooth or rough depending upon the material and method of manufacture of the bricks. I

Although I have shown preferred embodiments of my invention in the accompanying drawings and have described same in this specification it will be understood by those skilled in the art that variations and modifications may be made in the form and arrangement of the elements making up my improved checker work structure without departing from the spirit of my invention. 1 do not, therefore, wish to be limited to the specific embodiment herein shown and described but claim as my invention all forms thereof coming within the scope of the appended claims.

I claim:

1. Checkerwork consisting of solid brickwork columns, rectangular in cross-section and arranged checker-wise in parallel, staggered rows, the body portions of each of said columns being spaced apart and directly engaged by spacing members on each diagonally adjacent column and having all surfaces exposed for heat transfer except the contact points of said spacing members.

2. Checkerwork for hot blast stoves consisting of a plurality of columns, each column consisting of a plurality of smooth surfaced bricks of regular rectangular cross-section interspersed with spacer bricks of similar cross-section having projecting spacer members disposed to engage the walls of and hold adjacent columns in place.

3. Checkerwork consisting of a plurality of columns of rectangular cross-section held apart in parallel, staggered, non-contiguous rows by vertically staggered lug members forming straight gas passages alternately constricted in adjacent passages.

l. Checkerwork comprising columns of standard fire bricks of rectangular cross-section set on end and interspersed with spacer bricks, said columns being disposed checker-wise in parallel arrangement, said spacer bricks having lugs posltioned to space and locate adjacent columns.

5.111 checkerwork of the type described, a plurality of columns of substantially rectangular cross-section, said columns being arranged checker-wise and having flanges which extend into the spaces between adjacent columns and locate and support said columns, said flanges in adjacent columns being vertically staggered whereby staggered restrictions are provided in the gas passages between columns and a sinuous movement imparted to gas passing therethrough.

S. A checkerwork structure of the type described including smooth surfaced bricks of standard oblong cross-section arranged in spaced vertical columns to provide vertical flues, said columns including spacer bricks disposed between standard bricks, each spacer brick engaging corner portions only of standard bricks in the four diagonally disposed adjacent columns and being provided with portions which extend into the vertical flue spaces between said four adjacent columns and reduce the cross-sectional area thereof.

7. Checkerwork of the type described comprising vertical columns of standard bricks of oblong cross-section and spacer bricks, the standard bricks being set on end and the adjacent columns being spaced apart by said spacer bricks to form gas passages, the spacer bricks in any one column being located across joints between standard bricks in adjacent columns.

8. A checkerwork structure including bricks arranged in spaced vertical columns forming vertical lines, each of said columns comprising pairs of bricks of oblong cross-section in abutting end to end relation and spacer bricks between said pairs of oblong bricks, said spacer bricks engaging and breaking the joints between abutting 0blong bricks in each of the diagonally disposed adjacent columns.

9. Checkerwork of the type described comprising vertical columns of bricks of oblong crosssection and spacer bricks, the adjacent columns being spaced apart by said spacer bricks to form gas passages, the spacer bricks in any one column being located across joints between standard bricks in adjacent columns.

10. A checkerwork structure including bricks arranged in spaced vertical columns forming vertical fiues, each of said columns comprising pairs of bricks of oblong cross-section in abutting relation and spacer bricks between said pairs of oblong bricks, said spacer bricks engaging and breaking the joints between abutting oblong bricks in each of the diagonally disposed adjacent columns.

ARTHUR, G. MCKEE.

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