Detachment of Solid Particulate Soils by Centrifugal Force

Abstract

Polystyrene particles adhered to a glass plate was set in an ultra-centrifuge equipped with an angle rotor of which the angle being changed from 20° to 40°, were removed in various experimental conditions; i.e. washing time, rpm of centrifuge, and particle size.
Correlation between the removal force F_c (horizontal component F_h and vertical component F_v) vs. particle size has been observed, and the following results were obtained.
1) The removal percentage increased with increasing washing time, and particle size, and were proportional to rpm of the centrifuge.
2) The ratio of F_h and F_v were adjusted by changing rotor angle at constant F_c. The removal percentage increased with increasing F_h (i.e. decreasing θ).
3) The value of F_c necessery for the removal percentage of 50% were 80.5×10^-5 dyn, 12.6×10^-4 dyn for the particle diameter of 5μm, 15μm respectively at θ=30°.