Direct-fired inclined counterflow rotary kilns and use thereof

摘要

Method of operating a long direct-fired inclined counterflow rotary kiln for the thermal treatment of material and counterflow rotary kiln adapted for same, whereby material to be treated is introduced into the kiln at the inlet end (2) and treated material is evacuated from the kiln at the outlet end (1), whereby a main combustion zone (6) extends over a distance of ¼ to 1/3 of the internal length L_int of the kiln, whereby a supplementary combustion zone (5) extends over a distance from the inlet end (2) of at most ¼ of the internal length L_int, and whereby no combustion takes place in a heat exchange zone (7) located between the main combustion zone (6) and the supplementary combustion zone (8).