Abstract: Cement clinker is produced in that raw cement powder is preheated in a suspension-type heat exchanger and is de-acidified in a fluidized bed and clinkered in a rotary kiln, and the clinker is subsequently cooled. A de-acidification of at least 95% is effected at a temperature above 850.degree. C. in a circulation system comprising a fluidized bed reactor, a cyclone separator and a recycling duct. The carbonaceous fuel required for the calcining and clinkering processes is fed in an amount of at least 65% (related to the total heat requirement) to the de-acidifying fluidized bed reactor and in an amount of at least 10% (related to the total heat requirement) to the clinkering rotary kiln.The fuel supplied to the de-acidifying fluidizing bed reactor is burnt near stoichiometrically in two stages with fluidizing gas and secondary gas. The ratios of the rates and volumes of fluidizing gas to secondary gas are so selected that a mean suspension density of 100 to 300 kg/m.sup.
Type:
Grant
Filed:
February 18, 1982
Date of Patent:
January 10, 1984
Assignees:
Creusot-Loire Enterprises, Lafarge Coppee, Albert Folliot, Metallgesellschaft AG
Inventors:
Hans-Werner Schmidt, Hans Beisswenger, Lothar Reh, Albert Folliot, Maurice Paliard
Abstract: Cement clinker is produced in that raw cement powder is preheated in a suspension-type heat exchanger and is de-acidified in a precalcining apparatus and clinkered in a fluidized bed and the clinker is subsequently cooled. An de-acidification of at least 95% is effected at a temperature above 85.degree. C. in a circulation system comprising a fluidized bed reactor, a cyclone separator and a recycling duct. The carbonaceous fuel required for the calcining and clinkering processes is fed in an amount of at least 65% (related to the total heat requirement) to the de-acidifying fluidized bed reactor and in an amount of at least 10% (related to the total heat requirement) to the clinkering fluidized bed reactor. The fuel supplied to the fluidizing bed reactor is burnt near stoichiometrically in two stages with fluidizing gas and secondary gas. The ratios of the rates and volumes of fluidizing gas to secondary gas are so selected that a means suspension density of 100 to 300 kg/m.sup.
Type:
Grant
Filed:
February 18, 1982
Date of Patent:
September 6, 1983
Assignees:
Creusot-Loire Enterprises, Lafarge Coppee, Albert Folliot, Metallgesellschaft
Inventors:
Hans-Werner Schmidt, Hans Beisswenger, Lothar Reh, Albert Folliot, Maurice P. Iard