Apparatus and method for treating an aggregate material with a flowing gas.

摘要

Aggregate directed into a rotary kiln (12) is preheated continuously and in a highly effective manner by directing the aggregate downwardly along a passageway (35) formed by a pair of gas permeable retaining walls (36) which extend generally vertically in opposing spaced relation to one another. The retaining walls (36) are of a zigzag configuration so arranged as to direct the thin layer of aggregate along a sinuous path of travel in the course of its downward movement along the passageway (35) as heated gas from the kiln (12) is directed through the retaining walls (36) guiding the aggregate.