The mathematical modelling needed to simulate a constant rate filtration is described. In order to maintain a constant filtration rate the pressure drop over the filter will need to increase with time, as the increasing cake height will cause an increasing filtration resistance to fluid flow. This increase in cake forming pressure will cause an increase in filter cake concentration and resistance in compressible filter cakes. This is also modelled in the approach presented here. The modelling described can be applied in a spreadsheet, and is the basis of the online simulation included at the web site: www.particles.org.uk/filtration.
