Computationally efficient DEM simulation of a basket-type centrifugal filter using a novel switchable contact model

Abstract

The discrete element method (DEM) offers enormous potential to gain a better understanding of cake formation in centrifugal filtration. However, the necessity to represent the highly porous filter mesh in these simulations incurs a significant computational cost. We propose replacing the porous mesh boundary that is conventionally used with a ‘switchable contact model’ (SCM) in which the contact model between a particle and a continuous cylindrical shell is selectively enabled or disabled depending on the particle's location at the periphery of the centrifuge basket. SCM is disabled whenever a particle is deemed to be in contact with a pore location, thus allowing its egress from the basket. There was a ∼ 36 % reduction in computation time compared to the conventional mesh-based representation of a bounding filter mesh, with similar particle retention and bulk cake formation behavior. This concept could in principle be applied to model any repetitive porous structure in DEM.