Superquadric DEM study of the particle separation process in a multi-deck banana vibrating screen

Abstract

Efficient separation of non-spherical particles is necessary for various chemical engineering processes, including screening in recycling industries. Discrete element method (DEM) has become a widely used tool for designing screening processes. This study uses a superquadric DEM model to design a 5-panel multi-deck banana screen for the separation of a specific particle mixture, with varying densities, sizes, and especially shapes, including rod-shaped, chip-shaped, and spherical. Then the effects of vibration conditions (frequency, amplitude, angle), design parameters (inclination angle, panel numbers), and feed particle numbers on the key parameters, including separation efficiency and particle penetration rates, are quantified. The simulation results indicate that under the investigated conditions, the highest separation efficiencies are found at 2 mm amplitude, 20 Hz frequency, and 45° vibration angle, yielding efficiencies of 90.8 % for rod-shaped particles, 71.0 % for chip-shaped particles, and 46.5 % for spherical residues. Higher frequencies generally improve rod-shaped and chip-shaped particles separation but lead to fluctuations for the spherical fines. Final particle penetration rates increase with frequency but decrease at higher amplitudes for low to moderate frequencies. This work may serve as a theoretical reference for separation process optimisation in similarly configured screening systems.