GAS-SOLID FLUIDIZATION. IN TAPE RED-VESSELS

Abstract

Studies in gas-solid fluidization have been conducted in tapered vessels with circular cross-section. Materials fluidized include glass beads, crushed bauxite and calcite of different particle sizes. Tapered vessels of cone angles vary from 100 to 900 (Gas solid contact was found to be more efficient with larger particle sizes and smaller cone angles (100 to 300)). For smaller size of particles and larger cone angles the fluidization is limited to a cen-tral core with layers of particles remaining stationary near the walls. Slugging is more predominant in smaller angles cones. While in larger angle cones it is completely absent. Pressure drop data were obtained in the fixed bed region, at the onset of fluidization and in the expanded bed zone. Pressure peak which is. characteristic cif tapered vessels has been observed and correlated in terms of dimensionless groups like (Rep )m , '(B/Bo) and (tancc/2 ) The correlation obtained by curve fitting is -'0.08 0. +26 C ) 3•x+8 x 'l0-2 CID/Do )0* 97 (tan) ) (Rep ) net ref The experimental and theoretical pressure drops, have been calculated using computer and it was found that nearly 90% data vary between the range of ± 35 %. The coefficient of variation for all the data on glass beads, bauxite and calcite comes out to be 43.+9.