Patent ID: 6287110
Filing Date: 2001-09-11
Classification: C04B,F27B,Y02P

Abstract:
A system for thermal treatment of meal-like raw materials, in the manufacture of cement clinker from raw meal, whereby the raw meal is thermally treated in a burning process by pre-heating, calcining, sintering and cooling, and an exhaust gas stream of a sintering unit in the form of a rotary kiln and a tertiary exhaust air stream flowing through a tertiary air channel leading from a cooling unit are used in such a way for calcination of the raw meal in a calcining unit that at least one burning location is present both in an exhaust gas channel of the rotary kiln as well as in the tertiary air channel, whereby a gas/raw meal/fuel suspension coming from both channels is redirected in the calcining unit and is introduced into a lowest cyclone of a suspension-type cyclone pre-heater system for the purpose of separating a calcined raw meal from the gas stream, wherein:a) the tertiary air channel in the region of the calcining unit, is fashioned as a combustion chamber that expands the tertiary air channel cross section and through which the suspension flows from bottom to top;b) at a lower end of the combustion chamber at which the tertiary air enters with a torsion component, an easily ignitable fuel is centrally introduced, whereby a high-temperature zone that extends centrally from bottom to top and has a hot core flame proceeds from this burning location;c) a secondary fuel is introduced into a flame space of the high-temperature zone of the combustion chamber an is burned; andd) at least a sub-stream of the raw meal from a second-lowest cyclone stage of the suspension-type cyclone pre-heater system is introduced in a peripheral space between the flame space and a wall of the combustion chamber.