Some preliminary results from a research programme aimed at providing computer simulations for solid/liquid separation processes are presented. The personal computer software package described models the operation of pressure filters. The example of the diaphragm filter press is chosen, and it is shown how the integration of industrially proven research data with powerful modular software routines can simulate the cake formation, compression, dewatering and washing operations. With a knowledge of the intended operating conditions, the software generates extensive data for the filter cycle, and minimises the time and cost associated with preliminary and pilot-scale test work.