Numerical investigation of a vertical roller mill using DEM-MBD coupling method

Vertical roller mill (VRM) that involves the complicated motion of particles and mechanical components is a high-efficiency grinding equipment and has been commonly used to grind particle materials in industry. However, the previous researches for VRM are rather few and have some limitations. Consequently, a numerical simulation method of Discrete Element Method (DEM) coupled with Multi-Body Dynamics (MBD) is proposed in this work to study Kisen Vertical Mill (KVM), an external circulation vertical roller mill developed by Sinoma International Intelligent Technology Co., Ltd., for a deeper understanding of grinding process in the VRM, in which DEM is used to simulate the particle movement and the motion of mechanical components in KVM is predicted by MBD. The particle breakage is ignored in this work due to the inapplicability of the breakage model. This coupling method is first quantitatively validated against the results measured from the actual production. Subsequently, the relatively comprehensive DEM-MBD investigations for the influences of operational conditions (including the rotation speed of table, the height and the position of retaining ring) on the performance of KVM (e.g., the particle bed, the fluctuation of rollers, the grinding effect and the wear) are carried out. According to the simulation results, the particle flow behaviors would be significantly affected by these operational conditions.