PURPOSE: To utilize excessive air of high temp side of a cooler for preheating a powdery stock material by introducing said excessive air of high temp side of a cooler to a suspension preheater in case of cooling a powdery stock material after the calcination by air in a cooler.
CONSTITUTION: The excessive air of a high temp side of a cooler 17 of a calcination apparatus for a powdery stock material is introduced to an outlet duct 20 of a cyclone 2 of a suspension cooler 5 having a temp lower than that of said excessive air. Then, the powdery stock material supplied to the outlet duct 20 of the second stage cyclone 2 from a stock material supply apparatus 6 is floated in a mixed gas consisting of a waste gas from the cyclone 2 and the excessive gas from the cooler 17 and is preheated while conducting heat exchange. Thereby, the available heat utilization is attained and the fuel cost is reduced.
NOGUCHI HIROMI
KAWADA YOSHI
SAIGA TADAAKI
ABE HIDEKAZU
SUMITOMO CEMENT CO