Abstract
The optimum operating frequency and intensity of oscillating air applied to sieve fine powders are discussed.
As fundamental considerations, the non-linear Langevin equation, which describes the behaviours of a particle in a vertical oscillating fluid, is solved numerically. It is shown that the trajectory of a settling particle in the fluid obtained from the solution agrees closely with the experimental results. The behaviours of a particle on the sieve surface, which is in the oscillting fluid, is also analysed on the basis of this equation. The sieving rate of fine powders depends on the impact velocity between a particle and the sieve surface, because the velocity relates to the dispersion of agglomerates and the velocity of fine particles passing through an opening of the sieve. The number of collisions between a particle and the sieve surface is determined by the amplitude and frequency of oscillating air. These results show that there is an optimum condition of oscillating air applied to sieve fine powders.
