MEASUREMENT OF SIZE AND SIZE DISTRIBUTION OF PARTICLES BY FLUIDIZATION

Abstract

A method of particle size distribution measurement using a fluidization curve is developed.
The size distributions observed in binary and the tertiary mixtures were in agreement with those by microscopic measurement. For those mixtures the apparent minimum fluidizing velocity, if the particles were completely segregated, u_s, determined by
U_s=(ΣW_i/W_ou_mfi)^-1
where W_i/W_o is the weight fraction corresponding to u_mfi. The values calculated from the above expression were in good agreement with the experimental data.
The main disadvantage of this method is that, in the fluidization bed, the terminal velocity of the minimum-diameter particle must be less than the fluidizing velocity of the maximumdiameter particle, and the measurable size ratio (x_max/x_min) is 8-10.