Abstract
Hold-up of cohesive fine particles in a powder-particle spouted bed under continuous fines feeding was investigated. Nine powders, aluminium hydroxide and aluminium oxide materials, ranging in particle size from 0.51 μm to 3.5 μm (Group C powders in Geldart’s classification) were used. Silica sand particles of 920 μm in average diameter (Group D powders in Geldart’s classification) were used as coarse particles. Cohesive force of the fines was determined by the tensile strength method. The effects of superficial gas velocity, the feed rate of fines, the size of fines and cohesive force among fines on the hold-up of fines in the bed at a steady state were examined experimentally. It is found that fines hold-up is dominated by cohesive force and the effect of operating conditions upon the fines hold-up could be explained from the view point of the cohesive force.
