Abstract: A planetary cooler system is disclosed for cooling hot pulverous or granular material produced and exited from the discharge end of an inclined rotary drum such as a rotary kiln. A plurality of cooler tubes are mounted in planetary fashion about the material discharge end of the kiln with the axis of each tube in parallel, or approximately parallel, relation to the axis of the drum. A conduit communicates the discharge portion of the rotary drum with each cooler tube for the passage of hot material therethrough in countercurrent to preheated cooling air passing from the cooler tube to the drum to serve as combustion air. The conduit is so positioned as to divide each cooler into at least two sections, a first section of the cooler tube extending away from the conduit in a direction generally upstream of the flow of material inside the kiln, and the second section extending away from the conduit in a direction generally downstream of the flow of material in the kiln.

Abstract: A method of burning pulverous raw materials in a rotary kiln is disclosed wherein the material is preheated and at least partially calcined prior to subjecting it to a finishing heat treatment such as sintering. The calcination of the raw material is accomplished prior to the final burning by feeding preheated at least partially calcined raw material to the upper inlet end portion of an inclined rotary kiln and mixing it intimately with a fuel capable of producing a combustible gas. The combustible gas thus produced is passed to a calcination chamber communicating with the upper end of the rotary kiln. Substantially uncalcined raw material is suspended in the gas mix while an oxygen-containing gas capable of supporting combustion in the calcination chamber is provided causing the oxygen-containing gas to be ignited and calcined substantially isothermally.

Abstract: This invention relates to a method of manufacturing cement clinker from raw material in the form of cement raw slurry wherein the raw material is subjected to an initial heat treatment by bringing it into contact with hot gases by subjecting it to an initial spray drying in a spray dryer to convert the raw slurry into cement raw meal and preheated in a suspension preheater prior to burning it in a rotary kiln. Hot gases are directed from the rotary kiln to the preheater for preheating the spray dried raw meal while hot gases are directed to the spray dryer to provide heat for spray drying the raw slurry. A means for producing supplementary hot gases is provided with means for directing said supplementary hot gases in a manner to provide supplementary heat for heat treating the raw material prior to feeding it into the kiln. A rotary kiln plant for manufacturing cement clinker from raw material in the form of cement raw slurry according to the method of the invention is also disclosed.