Abstract: A cooler for cooling hot particulate material which has been subjected to heat treatment in an industrial kiln such as a rotary kiln for manufacturing cement clinker, includes a grate for receiving and supporting hot material from the kiln, at least one cooling gas duct which is connected to slots in the grate for introducing cooling gases into the hot material and a compressed air system for injecting compressed air into the material on the grate. The cooler also comprises at least one flow restricting device provided in the cooling gas duct. Use of the one or more flow restricting devices may permit only a very limited amount of the compressed air that is injected into the material on the grate to pass through the cooling gas duct.

Abstract: A cooler for cooling hot particulate material which has been subjected to heat treatment in an industrial kiln such as a rotary kiln for manufacturing cement clinker, includes a grate for receiving and supporting hot material from the kiln, at least one cooling gas duct which is connected to slots in the grate for introducing cooling gases into the hot material and a compressed air system for injecting compressed air into the material on the grate. The cooler also comprises at least one flow restricting device provided in the cooling gas duct. Use of the one or more flow restricting devices may permit only a very limited amount of the compressed air that is injected into the material on the grate to pass through the cooling gas duct.

Abstract: The present invention relates to a plant for manufacturing cement clinker. The plant consists of a preheater, a calciner in which the raw material is calcined at a temperature of more than 800.degree. C. and where fuel and oxygen-containing gas are fed to the lowermost zone of the calciner, and a kiln. The object of the invention is to provide a plant for manufacturing cement in which it is possible to bum lumpy fuel in a calciner, while simultaneously maintaining the possibility of increasing the time of retention and possibly the temperature of the material being fed to the lowermost zone in the calciner. This object is achieved according to the invention in that the calciner is provided with a fixed bottom (27) allowing combustible material fed to the calciner to be deposited on the bottom and in that oxygen-containing gas is fed horizontally to the calciner through openings in the lowermost zone of the calciner.