Abstract: For gas-tight lining of a chamber which is exposed to high temperatures a ceiling and wall construction is provided which is assembled from support bars, rows of profiled bearing bricks supported thereon and central bricks inserted between these rows of bearing bricks and profiled to fit together with these bearing bricks. Support bricks which are also suitably profiled are inserted between the bearing bricks on the one hand and the central bricks on the other hand, and the central bricks have a truncated pyramid shape which tapers towards the interior of the chamber to be lined. All bricks in the construction can be replaced individually in a simple manner.

Abstract: A rotary kiln has at one end circumferentially spaced apart outlet openings into each of which extends a sleeve establishing communication between the interior of the kiln and a planetary cooling tube. Encircling the inner end of each sleeve is a refractory collar that is flush with the surface of the kiln's lining. Between each tube and the edge of the associated outlet is a thermally insulative packing.