ABSTRACT
This paper presents the results of a preliminary work aimed at calculating the instationary motion of spherical particles in an air-pulsated jig from the mechanical properties of the jig. The model allowed the prediction of the pressure variations in the air chamber and the water velocity and particle trajectory in the wash box from such design variables as the volume of the air chamber, inlet and exit valve openings, type of the jig cycle, jig cross sectional area, pressure of the air reservoir, etc. A drag coefficient expression whih covers the entire range of practical Re numbers was used in the calculation of particle trajectory. Work is underway to test the model on a pilot scale jig and to extend the model for a bed of particles so as to cover the effect of bed height and solids concentration which bring about hindered settling conditions and viscosity changes.
