Prismatic refractory brick for glass melting furnace chambers

In a checker work in chambers of a glass melting furnace, wherein the checker work is a stack of layers of prismatic bricks of refractory material, the bricks in superposed ones of the layers being staggered relative to each other:

• each prismatic brick having an octagonal bottom surface, an octagonal top surface, a longitudinal axis extending between the surfaces, a single through passage of tetragonal cross section between the surfaces and coaxial with the longitudinal axis, inner walls defining the through passage, outer walls between the surfaces, the walls being parallel to the longitudinal axis, the bottom and top surfaces extending along major axes, the through passage having a hydraulic diameter of 120 to 200 mm, the hydraulic diameter being defined by the relationship:
• four times the through passage cross section divided by the periphery of the through passage cross section, and the ratio of the hydraulic diameter to the thickness of the hollow brick, measured in the direction of the major axes being between 3 and 5, recessed passages in the bottom surface extending from the through passage to a respective one of the outer walls, the product of the length of the line delimiting each recessed passage and the distance between the inner and outer walls being at least equal to the area of the recessed passage, the top surface having elevated portions extending perpendicularly to the major axes and having beveled end faces, and the bottom surface having corresponding depressed portions defined by bottom ends of the recessed passages having congruent beveled end faces and extending in the direction of the major axes.