Method and apparatus for calcining lime

Claim 1

In a method for calcining calcium bearing raw material in which finely divided raw material is successively treated in a preheating zone, a generally vertical calcining zone, and a cooling zone wherein the finely divided raw material is preheated in said preheating zone by exhaust gases from said calcining zone, passed through said calcining zone, and then in suspension through said cooling zone, the entire amount of cooling air being supplied directly from the cooling zone into the calcining zone as combustion air, the improvement which comprises: adding fuel to said generally vertical calcining zone at a plurality of locations following one another in the upward and onward flow direction of the gas passing through said calcining zone, introducing the preheated raw material closely adjacent to the lowest of said locations for immediate calcining effect at said lowest location, and passing the preheated raw material vertically upwardly through the calcining zone in concurrent flow with the fuel and while suspended in the gas stream.