Abstract: In apparatus for cooling hot material, a material transfer stage is provided in the material inlet of a cooler and acted on by cooling air. The transfer stage has a plurality of air-permeable carrier elements spanning the breadth of the inlet. At least one group of the carrier elements is arranged with a downward and forward inclination of approximately 10.degree. to 20.degree. in the direction of material transport. The carrier elements have forwardly facing sides provided with openings through which cooling air may pass.

Abstract: A planetary cooler has a plurality of circumferentially spaced cooling tube supports each of whichhas a pair of axially spaced side plates and an insert with two flanges which are fitted into openings in the side plates and welded to the latter. Each flange has a pyriform opening which communicates with a radial clearance extending between circumferentially adjacent side plates at their radially outer portions.

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 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.