1988 Volume 21 Issue 1 Pages 41-46
The fluidity of submicron powders was studied in a small-scale transparent column. Powders of Ni, Si3N4, SiC, Al2O3 and TiO2 were smoothly fluidized when gas velocity exceeded the apparent minimum fluidization velocity. The electrical conductivity of the particles did not affect the fluidizing quality in the range of the present experiments.
All the tested submicron particles formed agglomerates during fluidization. The agglomerate size and the apparent minimum fluidization velocity were dependent on species of particles and fluidizing gas. The equilibrium size of agglomerates calculated from the apparent minimum fluidization velocity and the sedimentation velocity was in the range of 70-700 μm. However, the agglomerates of CaCO3 and ZrO2 were very cohesive and could not be evaluated. The primary particle size was not a proper measure for the classification of fine particles.
