Vibratory particle size sorting in multi-component systems

Particle size segregation of granular mixtures due to shaking or vibrations has been observed in industries concerned with the handling and processing of particulates. Upon introducing the concept of relative concentrations between each size species, this paper presents a segregation model from which generalized expressions are derived for the instantaneous rate of change of concentration of each size species. The expressions are specialized to a ternary system. A Monte Carlo computer simulation study is done to simulate size sorting in a ternary system at a fixed shaking amplitude. The results of the simulations show good agreement with model predictions regarding the influence of particle size ratios. The most striking effect is a reversal of sorting order between the small and large particles with a change of size ratios. This reversal, which occurs in the simulated system, is clearly explained by the model.