Abstract
Accurate classification of very fine powder is becoming a subject of wide interest in various fields of industry. In these days, water elutriator and batch settling classifier are used for this purpose. In order to make accurate classification by the use of these devices, it is necessary to understand the behavior of particles having wide size range in suspension. However, the great majority of works on sedimentation phenomena in suspension has hitherto dealt with particles of uniform size. In this investigation, classification of fine powder by batch settling classifier is undertaken to clarify the sedimentation phenomena of fine particles in suspension. On the basis of this experimental results, the following equation is proposed for the settling velocities of particles having wide size range in suspension.
u=us·ε2·10-1.82(1-ε)·[Dc]-n
where the exponent n is a function of Reynolds number of particles and size distribution.
