Operation parameters optimization of a separating system for non-ferrous metal scraps from end-of-life vehicles based on coupled simulation

摘要

End-of-life vehicles (ELVs) provide a particularly potent source of non-ferrous metal scraps. At presents, conveyor belt and air-jet nozzle are widely used in the existing separation system for non-ferrous metal scraps. Parameters such as shape of the scraps, conveyor belt speed (ⅴ), nozzle air pressure (P) and nozzle angle (α) have a significant influences on the separating accuracy and efficiency. To investigate the interaction between these parameters and their influences on the separation distance, a coupled simulation model of (Discrete Element Method) DEM and (Finite Element Method) FEM was employed to simulate the motion of the scraps and the separation process, the trajectory of the scraps under different circumstances was recorded and analyzed, the simulation model was verified using a separation platform. The results indicated that block shaped scraps have the largest separation distance followed by rod and slice shaped scraps. The separation distance of rod and slice shaped scraps increases when each of the three parameters increases, and the speed of conveyor belt (ⅴ) plays a dominant role. For blocks shaped scraps, when nozzle pressure is high, the separation distance increase with the increase of conveyor belt speed, when nozzle pressure is low, the separation distance decrease with the increase of conveyor belt speed. The nozzle pressure (P) was found to have the most noticeable impact on separation distance for block shaped scraps. For the platform in this study, the optimal operation parameters obtained were v = 1.9 m/s, P = 0.53 MPa, and α = 42°.