CFD-DEM study of bridging mechanisms at the static solid-liquid surface filtration

Abstract

In static surface filtration processes with filter media which pores are bigger than the particle size, the formation of bridges from particles over the pores is of crucial importance for the creation of the first particle layer and interference resistance of the filter. To achieve a better understanding of the bridging mechanisms, a numerical study of the particle deposition with a three-dimensional columnar pore model of a filter was performed using a coupled CFD-DEM approach. The time for bridge formation with spherical particles over the filter pores was obtained for different concentrations and inlet flow velocities. Furthermore, the simulation results were analyzed to investigate the total filter resistance, which results from interferences between filter medium, particles and fluid. The simulated characteristic filtration curves at a constant flow rate are in good agreement with the filtration model. Moreover, the bridging dynamics predicted by simulations agrees with the previously obtained experimental results.