Patent ID: 6030448
Filing Date: 2000-02-29
Classification: C04B,F27B,Y02P

Abstract:
A method of producing cement clinker from cement raw material comprising:a. delivering cement raw material to a preheating zone;b. heating the material in said preheating zone;c. delivering preheated material to a calcining zone;d. heating the preheated material in said calcinating zone to a partial calcining temperature of between about 850.degree. and 900.degree. C.;e. delivering partially calcined material to a heating zone having rising and descending flow sections through which said partially calcined material flows in succession;f. further heating partially calcined material in said heating zone to an elevated temperature of about 1200.degree. C. but below that at which the material begins to become molten;g. delivering the further heated material to a burning zone;h. burning the further heated material in said burning zone at a temperature to form clinker;i. delivering clinker to a cooling zone through which cooling gas flows and is discharged therefrom as hot exhaust gas;j. delivering portions of hot exhaust gas and fuel to each of the burning zone, the heating zone, and the calcinating zone;k. delivering at least a portion of said partially calcined material and the respective portion of hot exhaust gas and fuel to the rising section of said heating zone to form a flowing treatment stream of said gas, said fuel and said portion of said partially calcined material;l. passing the flowing stream successively through said rising and descending sections of said heating zone while subjecting the further heated material to centrifugal and gravity forces to precipitate further heated material from said stream; andm. introducing the precipitated further heated material directly into said burning zone.