Calcining apparatus for powdery materials

Abstract

There is here disclosed a calcining apparatus for a powdery material comprising a first preheating series composed of a calcining kiln and preheaters at a plurality of stages for heating the powdery material with an exhaust gas from the calcining kiln, a second preheating series composed of other preheaters at a plurality of stages for heating the powdery material with an exhaust gas from a rotary kiln, and a gas carrying pipe for connecting the first and second preheating series in the middle thereof, a flow path for the powdery material being adapted so that the powdery material fed to each series may be led into the rotary kiln via a combining duct disposed in front of the undermost preheaters in both the series and then via the undermost portions of both the series. Further, disclosed is a calcining apparatus for a powdery material in which a sub-calcining kiln and a calcining chamber are disposed on an exhaust gas pipe extending from a rotary kiln. Still further, disclosed is a calcining apparatus for a powdery material in which a calcining chamber is disposed, and a flow path through which the powdery material fed to first and second preheating series passes is provided with a powdery material carrying pipe for connecting both the series in front of the second preheaters from the bottom in both the series, and is further provided with a combining duct for combining powdery materials from both the series in the rear of the second preheaters from the bottoms in both the series.