Abstract: The invention relates to the production of cement clinker from cement raw material using a preheating zone, a calcination zone, a heating zone in which the calcined material is further heated whilst avoiding the formation of a molten phase, as well as a clinker burning zone and cooling zone from which part-quantities of the hot exhaust air are delivered as combustion air together with proportions of fuel to the clinker burning zone, the heating zone and the calcination zone. A reliable further heating while avoiding incrustations is achieved in the heating zone by constructing this zone in the manner of a flue stream reactor to which calcined material, fuel and combustion air are delivered in the lower end region of a rising first treatment zone at one point in each case and from which the heated material is precipitated essentially by the effect of gravity overlaid with centrifugal action.

Abstract: A method of and apparatus for decontaminating contaminated soils and similar materials, the method includes (a) drying and comminuting contaminated soil and similar material in a mill through which a flow of hot gases is passed to provide a mixture of solids and gases; (b) introducing the mixture into a cyclone separator where the mixture is separated into gaseous and solid components; (c) thermally treating the solid components in a decontamination zone at a temperature effective to decontaminate at least a portion of the solid components; (d) passing the solid components after thermally treating same in step (c) into a dwell zone configured as a flow-through region; (e) thermally treating the solid components within the dwell zone at a temperature effective to decontaminate at least a portion of the solid components; (f) cooling the solid components after step (e) by transferring same into a cooling region of a cooling line; (g) thermally afterburning gaseous components from at least one of steps (b) and (c

Abstract: A method and arrangement for reducing the circulation of salts in a cement kiln in which a raw meal heat exchanger feeds material to the kiln. A partial gas stream charged with harmful substances is removed from the kiln through a bypass conduit. The partial gas stream is subjected to a multi-stage process of removing dust. This process includes passing the partial gas stream through a first dust separating stage, followed by returning an uncooled dust component of the partial gas stream to the kiln and cooling the remaining portion of the partial gas stream. The cooled remaining portion of the partial gas stream is subjected to a further dust separating process, and thereafter passed through a further bypass conduit to a location of the raw meal exchanger, which location has a temperature at approximately the same level as the temperature of the remaining portion of the partial gas stream entering the further bypass conduit following the further dust separating process.

Abstract: The invention relates to a method and apparatus for the heat treatment of fine-grained material wherein a precalcination zone formed by the kiln exhaust gas duct of a rotary kiln and into which two branch streams of cooling air which have been subjected to opposing rotational flow are introduced. In this way an equalization of the speed profile over the cross-section of the kiln exhaust gas duct and an improvement in the burning up of the fuel is achieved.

Abstract: Fine-grained material such as raw cement meal is preheated in a multi-stage cyclone preheater, precalcined in a precalcination zone, sintered in a rotary kiln, and cooled in a cooler. Exhaust gases from the kiln are delivered to the precalcining zone and then to the preheater. Tertiary air from the cooler is divided into two streams one of which is mixed with kiln exhaust gases between the kiln and the precalciner and the other of which is delivered directly to the precalciner. The quantity of tertiary air flowing through each branch is regulated to maintain the temperature of the kiln exhaust gases at a selected value.

Abstract: The invention relates to a multiple-stage heat exchanger 1 in which at least one of the lower heat exchange stages contains a deflector/separator with a horizontal gas inlet pipe and a gas outlet, and at least the upper heat exchange stage has a conventional cyclone. This results in a considerable reduction in the energy requirement, the size and height of the construction.

Abstract: A process for producing cement wherein preheated, partially calcined powder-form raw material is finally calcined in a fluidized bed and is discharged to a cooler through which a cooling stream of air passes. A part of the cooling air passes into the fluidized bed from below and another part of the cooling air, together with the partially calcined material, passes into the fluidized bed from the side. The rates of material flow to and from the fluidized bed is regulated to maintain a substantially uniform intersticial ratio between the upper and lower regions of the fluidized bed.

Abstract: Fine solid material is preheated in a first zone, then heated to the final treatment temperature by passing it through a flame in a second zone, and then separated in a third zone from the hot exhaust gases leaving the second zone. The separated exhaust gases are led to the first zone for preheating the material. A fuel feed stock is gasified to produce a combustible gas, and such gas is burned in the second zone to produce said flame.