CHARACTERISTICS OF FLOW BEHAVIOR IN SEMI-CYLINDRICAL SPOUTED BED WITHDRAFT TUBE

A fold model experiment using semi-cylindrical spouted bed with a draf t tube was carried out to improve the performance of a spouted bed-typ e coal gasifier, The effects of the gas now rate, tube-cone clearance, included angle of conical base, particle diameter and bed weight on t he 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, incl uded angle of conical hare and the mean particle diameter but decrease d with increasing the bed weight. The particles circulation rate incre ases with increasing in the tube-cone clearance, the mean particle dia meter and the bed weight. Tendencies of the change of particle circula tion rate with gas feed rate for 5 pi/18 and 6 pi/18 of included angle are different from those for 7 pi/18 and pi of included angle in the region of high gas feed rate. Correlations to describe the annulus gas velocity and particle circulation rates are obtained.