Computer software for the simulation of solid/liquid separation equipment

This paper details aspects of Filter Design Software® (FDS), Windows® software for the selection and simulation of solid/liquid separation equipment as well as the analysis of test data. FDS has been developed in collaboration with multi-national companies spanning a wide range of industrial sectors to provide a comprehensive calculation, education and training tool that maintains a balance between ease of use, level of knowledge conveyed and comprehensibility. The selection module of the FDS compares up to 7 user-defined selection criteria with information contained in databases to produce a numerically ranked list of potentially suitable equipment. The FDS allows access to text and pictorial descriptions of more than 70 equipment types and hyperlinks provide more specific equipment manufacturer details via the internet. The data analysis module facilitates interactive analysis of leaf filtration, jar sedimentation and piston press test data. Calculations are performed in a hierarchical manner using the available information, if some data are not measured then the FDS performs the best possible analysis using approximations. The results of an analysis can be used to refine (shorten) a list of selected equipment or provide scaleup information for equipment simulation. Results in the paper concentrate on the equipment simulation capabilities of FDS. More than twenty types of vacuum and pressure filters can be simulated which potentially involve combinations of cake formation, compression and gas deliquoring, and washing. By way of example, the operation of a pressure Nutsche filter that is required to process a pharmaceutical product is simulated and the predicted influence of crystal formation and other operating parameters on the filter cycle are shown. Simulations quantify how crystal form can detrimentally influence all phases of a cycle and lead to, for instance, slower filtration and wetter cakes.