Characteristics of Flow Behavior in Semi-Cylindrical Spouted Bed with Draft Tube

Abstract

A cold model experiment using semi-cylindrical spouted bed with a draft tube was carried out to improve the performance of a spouted bed-type coal gasifier. The effects of the gas flow rate, tube-cone clearance, included angle of conical base, particle diameter and bed weight on the solids flow behavior in the unit are investigated. The gas velocity in the draft tube depended on the gas feed rate. The gas velocity in the annulus increases with increasing in the tube-cone clearance, included angle of conical base and the mean particle diameter but decreased with increasing the bed weight. The particles circulation rate increases with increasing in the tube-cone clearance, the mean particle diameter and the bed weight. Tendencies of the change of particle circulation rate with gas feed rate for 5π/18 and 6π/18 of included angle are different from those for 7π/18 and π of included angle in the region of high gas feed rate. Correlations to describe the annulus gas velocity and particle circulation rates are obtained.