The invention relates to ring furnaces of which at least one of the inner partitions is formed by a plurality of bricks made of refractory material including at least a first brick and a second brick placed above or below a third brick and separated from one another by a space of width J, in which the first brick has at least one recess on its assembly face opposite the third brick, the third brick has at least one projection on its assembly face facing the first brick, wherein the projection is inserted into the recess, the dimension E of said recess in the longitudinal direction of the partition is greater than the dimension B of said first projection in the same direction, and said recess is positioned at a determined distance Se from the end face adjacent to said space.