A network model to assess base-filter combinations

Abstract

Granular filters retain base material within the narrowest constrictions of their void network. A direct comparison of the base material particle size distribution (PSD) and the filter constriction size distribution (CSD) cannot easily be used to assess fi lter - base compatibility. Here a conceptually simple random - walk network model using a filter CSD derived from discrete element modelling and base PSD is used to assess filter - base compatibility. Following verification using experimental data the model is a pplied to assess empirical ratios between filter and base characteristic diameters. The effects of filter density, void connectivity and blocking in the first few filter layers are highlighted.