Abstract: An apparatus for treating raw material comprises a mixing chamber having fuel and air inlets for admitting therein fuel and air which are mixed to produce a combustible mixture. A combustion chamber receives the combustible mixture and burns the same to evolve hot products of combustion which are fed directly into an adjoining conditioning chamber. Additional gas is supplied to the conditioning chamber and mixed with the products of combustion to form a conditioned treating gas having a prescribed temperature and composition. To promote rapid and uniform mixing of the gases and hence form a uniform treating gas, the conditioning chamber is connected directly to and has a volume one and one-half to six times greater than that of the combustion chamber. A treating chamber disposed downstream from the conditioning chamber receives both the preconditioned treating gas and the raw material to be treated and the raw material is acted thereon by the treating gas while temporarily stored in the treating chamber.

Abstract: A method for treating raw material comprises mixing fuel and air in a mixing chamber to produce a combustible mixture, ejecting the combustible mixture into a combustion chamber and burning it therein to evolve hot products of combustion which are fed directly into an adjoining conditioning chamber. Additional gas is supplied to the conditioning chamber and mixed with the products of combustion to form a conditioned treating gas having a prescribed temperature and composition. To promote rapid and uniform mixing of the gases and hence form a uniform treating gas, the conditioning chamber is connected directly to and has a volume 11/2 to 6 times greater than that of the combustion chamber. A treating chamber disposed downstream from the conditioning chamber receives both the preconditioned treating gas and the raw material to be treated and the raw material is acted thereon by the treating gas while temporarily stored in the treating chamber.