Patented Oct. 22, 1946 2,409,873 UNITED STATES PATENT` ori-'ICE 2,409,873 HEAT EXCHANGE Howard Y. Lankford, Gary, Ind., assignor to Car negie-Illinois Steel Corporation, a corporation of New J ersey‘ l Application June 6, 1945, Serial No. 597,922 8 Claims. (Cl. 263-51) 2 This invention relates generally to heat ex changers, and more particularly to an improved ' construction and arrangement of the bricks form ing the checkerwork thereof. . While not limited thereto, the'herein claimed invention has its greatest utility in the checker to force the hot gases or air into all corners’ and crevices of the flues to thus improve utilization of all available heating surfaces and brick. Volume, thus making for an increased rate of heat ex change. Another object is to provide an improved check work used in hot blast stoves of the type used to erbrick so constructed and arranged that an in preheat air supplied to support combustion and terlocking effect is obtained between adjacent bring about reducing reactions in a blast furnace. bricks to thus prevent relative movement or creep As is known to those skilled in the art, such hot 10 ing of the bricks under the influence of expansion blast stoves are in the nature of huge brick-lined and contraction due to alternate heating and steel sheels approximately 20 feet in diameter cooling. ` and 80 feet or more in height. Within the lining As will be more fully apparent hereinafter, the it is customary to provide a division wall defining above and related objects are made available by a combustion chamber, and the balance of the the use of a novel form of Checkerbrick of gen space is substantially filled with refractory brick erally rectangular prismatic form whose horizon checkerwork forming a system of flues. In normal tal top and bottom faces are flat, whose vertical operation blast yfurnace gas is burned in the com end faces are also flat, and whose upright side bustion chamber of the stove and the stack draft faces have one or more shallow pyramidal later draws the hot burned gases through the multiplic 20 ally projecting portions which project into the ity of flues‘formed by the checkerwork. As the flues formed by the juxtaposed brick. The pyram gas is passed through the checkerwork, each brick idal projections serve to provide more heating absorbs and stores part of the heat. Periodically surface than that of a standard brick, and they the supply of combustion gas is cut 01T and the also function to create a turbulence of the air'or blast main is opened, thereby admitting cold air 25 gas flowing through the checkerwork. This tur under pressure to the stove. The cold air passing bulence is advantageous as it dislodges precipi through the >many flues of the checkerwork ab tated dust and thus more of the hot gas or air is sorbs heat therefrom, thence flows to the hot blast brought into intimate contact with the surfaces of main leading to the bustle pipe of the blast fur the Checkerbrick, thus increasing the efficiency nace in a manner well known to those skilled in 30 of the heat transfer. For a more complete understanding of the in Practice has demonstrated that although blast vention, reference should be made to the accom furnace gas passes through primary washers be panying drawing, the following detailed disclos fore being introduced into the hot blast stove, ure, and the appended claims. there is still considerable dust entrained in the 35 In the drawing: \ gas which has a tendency to precipitate on various Figure 1 is a horizontal section on a small scale ledges formed by conventional forms of checker through a hot blast stove to illustrate the applica brick. Checkerbrick heretofore used are open to tion of the invention. ‘ various objections, the chief of which is that they Figure 2 is an enlarged fragmentary top plan of are of such form that they promote the accumula 40 a portion of the checkerwork of a hot blast stove tion of objectionable dust deposits. embodying the present invention. An object of the present invention is.to provide Figure -3 is a vertical section on line III-III an improved checkerwork structure for hot blast of Figure 2. ` stoves, overcoming inherent shortcomings in the Figure 4 is an enlarged plan view of my im prior art. 45 proved Checkerbrick. A further object is to provide an improved brick ‘ ' Figure 5 is a front elevation of the brick of Fig theart. ' ` n ‘ so constructed and arranged that it furnishes an ure 4. Y increased heating surface for the checker chain ber. Another object is to provide checkerwork form Figure 6 is a vertical end View of Figure 5. Figure 'I is a perspective view of my improved 50 Checkerbrick. ed of bricks having portions constructed and ar Figure 8 is a perspective view illustrating the ranged to create a turbulence in the hot gases or relationship of a plurality of bricks constituting air passing through the iiues. the improved checkerwork. A further object is to provide means to create a turbulence of hot gases or air in the flues in order Referring in detail to the drawing, reference numeral l0 represents the conventional `outer 5.5 » 2,409,873 4 3 exposed faces of the checkerbrick are forcibly impinged by the air or gas, thus effectively pro steel shell of a hot blast stove; I2 represents the usual brick lining; and Ilä represents the wall moting and increasing the heat transfer. The which with a portion of the lining I2 defines a turbulence caused by the pyramidal projections combustion chamber I6. The balance of the stove is substantially filled with checkerwork such 5 also creates a “core busting” effect on the gas stream; that is to say, the turbulence tends to as indicated at I8, this checkerwork being formed «break up any vortex or core-.like denseaccumula~ of a novel type of checkerbrick best shown in Fig tion of dust particles inthe gaseous stream. ures 2 to 6 inclusivev andto be presently described Comparing a standard checkerbrick with that in detail. The bricks are formed of refractory 10 v„of my invention as herein described, it is found material commonly used in the art. that a standard 8% inch by 6 inch by 21/2 inch As will be apparent from Figures 4 to ‘7 inclu brick such as commonly used has a heating area sive, my improved checkerbrick is of generallyv of 70.5 square inches. The total volume of all checkerbricks that can now be installed with a top and bottom faces 20 and ‘22 and nat upright substantially vertical end faces 24 and 26. The 15 basket-weave. pattern in a typical furnace in a typical hot blast stove is 13,900 cubic feet, with a upright side faces 2B and 30, instead of being flat total heating surface o-f 93,606 square feet. In _ like all the other faces described, are equipped comparison, a brick of my invention measuring with a plurality of shallow pyramidal projections. rectangular prismatic form having parallel flat approximately 83/8 inches by 6 inches by 21/4 For the purpose of identification the pyramidal projections of the face 28 are indicated at 2128a 20 inches has a heating area of 76.06 square inches. By using my improved brick in a comparable and 28h. Likewise the pyramidal projections on stoveinstead of the standard brick using the same basket-weave pattern, the total volume of check erbrick would be 15,056 cubic feet, having a com Between the pyramidal projections 20a and 2W’ the side face 28 includes a flat portion 26C. Like 25 bined heating surface of 109,855 square feet. Thus an important advantage of my invention is wise, between the pyramidal projections 30a and an increase of approximately 8 per cent (7.9) 3!)b there is a flat portion 30C. The distance, the opposite side face areindicated at 30a and 30h. ’ ' » . in the effective heating area of a stove of 'com marked d, between the bases of these projections, is at least equal to the dimension c, so as to pro parable size. The flue openings with the‘stand vide a seating area substantially equal to the 30 ard bricks are 3 inches by 3 inches, or 9 square inches. My improved brick will have the same area‘of the end faces 2-1Y or 26 of a similarV brick » iiue area at the top and bottom edges of vthe arranged »perpendicular thereto. This relation brick, but at the intermediate portions in the ship, as clearly illustrated in Figures 2 and S, region of the apexes of thepyramids the flue area provides an assemblage in which the bricks ex tending lengthwise in one direction are interlocked 35 will be 7.1 square inches. Thus the air or gas flowing through the ñues formed by my brick by the pyramidal projections with tho-se bricks will exert somewhat of a venturiv effect, which extending perpendicular thereto. will set up the turbulent action above mentioned, The apexes a and b ofthe pyramidal projec effective to dislodge accumulated dust and thus tions-28a and 28?D are inline, as shown by line .A-A 40 increase the over-all efliciency of the hot blast in _Figure 5, this line A-A being offset a distance O from a center line B-B located midway be Having thus described my invention,V Vwhat I tween the top face 20 and the bottom face 22 of desire to secure by Letters Patent is‘outline'd' in the brick. By thus offsetting the apexes I-am en the appended claims. ` abled to lay up `the bricks in such a relationship ' as tovobtain an increased turbulence. The stag gered relationship of the inclined faces v4of the pyramids will be apparent from the enlarged ver tical section of Figure 3., The apexes a and b on opposite sides of the brick are in line> with -one another, as is apparent from Figuresß to 6. The locations of said apexes of each brick may be said to be in line with one another and offsetfrom `the center plane B-B paralleling the top _andbottom 45 stove. ' ' I claim: .1. A heat exchanger including checkerwork comprising a- plurality of bricks of generally rec-` tangular prismatic form whose horizontal top and v I bottom faces are flat, whose vertical ehd faces 50 are also fiat, and certain of Whose upright. side faces each have at leastone shallow pyrainidal laterally projecting portion. ' ‘ l ì '_ v2. The heat exchanger as defined in claim l, v further characterized in that theV apex o-f said faces of the brick. -In Figure 3 the apexes a Aof the lbricks-shown 55 pyramidal projection is offsetrfrom a cente?plan'e paralleling the .top andvbottorn faces `of the brick. in 4end elevation correspond in location;_ to `the `3. A heat exchanger including checkerwork comprising a plurality of substantially identical bricks of generally rectangular prismatic form that is, their apexes are >oifsetdownwardly from 60 whose horizontal top and bottom faces’aiï‘e 'flat,. whose vertical end'faces arealso flat, andwhose the center line of the brick. As thus arranged, the showings of said apexes in the detail Views» of Figures 4, through 7, while the bricks shown` cut by the plane of section in Figure 3 are inverted; be staggered vertically with relation yto thefapexes vvertical side faces each have -a plurality of spaced-,apart pyramidal projections. ., set vertically equal distances corresponding to the 4dimension o on opposite sidesl of a horizontal .plane projections on opposite sides of the brick are in line with one another and are offset fromacenter apexes a’ of the sectioned bricks may be said to a'of the bricks disposed perpendicular thereto. ‘ Y ’ 4. ‘The heat exchanger of claim 3, further` char Otherwise expressed, the apexes a and a’ .arejoff 65 acterized in that the .apexes of the >pfyramidal B-B passed through the bricksmidway ,between ' the top and bottom faces thereof. The presence plane paralleling they top Vand bottom faces .of the brick. ` 'I ‘ ` of the multiplicity 0f vpyramidal projections ex 70 5. A heat exchangerY including checker-work comprising a multiplicity -of substantially iden tending into the flues formed by the assemblage'of tical bricks of generally rectangular prismatic bricks creates a turbulence ,of the :air and gas form laid up b-asket'weav'e fashion, With end-'faces passed through the checkerwork which is effec- . óf certain of the bricks abutting side facesof tive to dislodgev dust which may tend'to precipitate on the checkerbrick, and the net result is that all 75 other bricks disposed perpendicular thereto, all , 5 of said bricks having fiat top, bottom, and end faces, the top and bottom faces being horizontal and the end faces being vertical, the side faces of all said bricks having shallow pyramidal pro. jections which thus extend into the flues defined 6 '7. A checkerbrick for use in a heat exchanger, comprising a substantially rectangular prismatic refractory body having substantially parallel fiat top and bottom faces, iiat end faces substantially perpendicular thereto, and side faces each having a pair of pyramidal projections with a flat area between them of substantially the same size and tions being eifective to create a turbulence of air shape as the end faces of the brick. or gas passed through said ñues. 8. The brick as defined in claim 7, further 6. The heat exchanger as defined in claim 5, further characterized in that the side faces of 10 characterized in that the apexes of said pyramidal projections lie in a common plane offset from a said brick between the pyramidal projections plane midway between the top and bottom face include a flat portion whose extent is at least of the brick. equal to the distance between the side faces of collectively by the bricks, said pyramidal projec the brick as measured horizontally, so as to form a seating surface for the upright end face of an 15 identical brick. HOWARD Y. LANKFORD.