Abstract: A grate cooler arranged at right angles to a rotary kiln and having its vertical longitudinal central plane spaced a distance between 10 and 150 cm from the discharge end of the rotary kiln. The zone of the grate cooler lying below the material discharge end of the rotary kiln has more stationary grating plates and more unventilated grating plates per unit area than the laterally adjacent zones of the material receiving end and in the remaining region of the cooler. This results in good protection of the grating plates at the material receiving end and an even distribution of the material over the whole width of the cooler by means of a distribution cone which is kept in motion.

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.

Abstract: A rotary kiln having a row of planetary cooler tubes disposed around its outer periphery and carried by individual metal mountings on the kiln casing, adjacent mountings abutting against each other in their areas bordering on the kiln casing and being spaced apart in their areas remote from the kiln casing, for minimizing changing temperature induced stresses imparted therefrom to the kiln casing during operation.

Abstract: A rotary kiln has a cylindrical casing interrupted along its length by annular members which are welded into and constitute part of the casing and which are provided with outwardly projecting, profiled webs adapted for attachment to the mounting structure of cooler tubes which are arranged in planetary manner about the casing.

Abstract: A plurality of cooling tubes are arranged in planetary fashion about the periphery of the kiln. An inlet for each cooling tube includes a transition member extending from one end of each tube, which transition member comprises the wall of an inclined frustum whose base lies on the end of the cooling tube in a plane perpendicular to the axis of the tube. An inlet tube has one end intersecting the wall of the kiln and its other end intersecting the wall of the transition member, two surface lines of the transition member being tangent to the inlet tube.

Abstract: This invention relates to a rotary kiln for the heat treatment of material and having a number of elongate satellite cooling tubes distributed uniformly around the rotary kiln periphery at the exit end of the kiln, the inlet ends of these tubes being connected by short inlet pipes to the interior of the rotary kiln, and each tube being supported on the rotary kiln casing by two support bearings which accommodate axial movement of the tubes relative to the kiln occasioned by thermal expansion or contraction of the tubes. Mounting of the bearing means accommodates a close spacing between adjacent tubes.