Evaluation of Effect of Feed Rate in a Hydraulic Gravity Separator for High-Quality Plastic Separation Using DEM-CFD Simulation

Abstract

To recycle plastics in automobile shredder residue (ASR) is strongly required to reduce the amount of incineration. Using the slight difference in specific gravity of plastics made of different materials and additives, a separator using the difference of settling velocity in water is considered as a promising process. However, a high feed rate in the separator often decreases the recovery or grade of plastics. To contribute to the optimized design of the separator, this research evaluated the effect of a feed rate on the recovery or grade by the discrete element method coupled with computational fluid dynamics. Simulation results showed that as the feed rate increased, the contact number and the residence time of plastics increased, and the floating of plastics was hindered, resulting in a decrease in the recovery rate of the particles.