Method and apparatus for calcining fine grained material

Abstract

Method and apparatus for burning fine grained material, particularly for the manufacture of cement clinker whereby the product quality is enhanced. At least a portion of the exhaust gases from the kiln at a temperature of about 1000.degree. to 1300.degree. C. are cooled by passing them through a steam generator to a temperature of about 200.degree. to 300.degree. C. At least a portion of the noxious substances such as alkali chlorides and sulfur are condensed out of the gas stream as well as possibly some mineral particles such as partially deacidified kiln dust. The materials condensed out of the gas are separated in the steam generator by means of periodic or continuous cleaning of the heating surfaces of the steam generator. The steam which is generated in the generator is conducted to at least one prime mover such as a steam turbine or a steam motor for the purpose of producing electrical or mechanical energy. In this way, the economic feasibility of cement clinker burning systems equipped with bypass devices is considerably increased by exploiting the high thermal potential of the bypass gases.

Dependencies are inferred from the claim text.