Simulation of particles and sediment behaviour in centrifugal field by coupling CFD and DEM

Centrifugal separation systems, such as solid bowl centrifuges, are used to effectively separate fine particles from industrial fluids. Knowledge of the streams and sediment behaviour inside such solid bowl centrifuges is required to determine the geometry and the process parameters that lead to an optimal performance. The multiphase flow of water, air and particles is calculated numerically in a cylindrical solid bowl centrifuge using a Computational Fluid Dynamics (CFD) software coupled with a Discrete Element Method (DEM) software. The CFD software calculates the flow of water and air and transfers the hydrodynamic forces to the DEM software in order to calculate the particle positions adding the hydrodynamic effect to the contact forces. Afterwards, the influence of the particles on the flow is considered. Thus, an unsteady and coupled simulation calculates flow and particles alternatively. Different sediment forms and solid volume concentrations are obtained when varying the geometry, operating conditions, particle size and contact model parameters such as the friction coefficient.

► Simulation of the multiphase flow in a centrifuge using a coupling of CFD and DEM. ► Analysis of the solids volume concentration in the sediment formed. ► Analysis of the effect of the particles on the flow pattern. ► Sediment dependence on the rotational speed, particle size and friction coefficient.