To prevent the vertical joints of the inner cylinder brickwork of coke dry quenching equipment from loosening and opening and in its turn causing the collapse of brickwork by forming engaging grooves and engaging projecting lines on the inner cylinder brick in such a manner that they cross the direction of the periphery of the inner cylinder at right angles, and engaging the grooves and the projecting lines of each of the laid bricks.

The figure shows an oblique drawing wherein a prechamber 2 is formed on the upper part of a cooling chamber 1 of coke dry quenching equipment by partitioning a circular duct 4 by an inner cylinder 3 consisting of brickworks. Each inner cylinder brick has two parallel engaging grooves 7 formed on the upper side and two parallel engaging projecting lines 6 formed on the lower side in such a manner that the grooves 7 and the projecting lines 6 cross the peripheral direction of the cylinder 3 at right angles. The inner cylinder has a constitution wherein the bricks are used in such a manner that one of the two engaging grooves on a brick is engaged with the projecting line formed on the lower side of a brick laid thereon while other groove is engaged with the projecting line formed on the lower side of a brick laid thereon and adjacent to the afore-mentioned brick laid thereon to thereby make the vertical joints of the inner cylinder breaking joints.