Modeling and Simulation of Filtration Processes

Finding advanced filtration and separation solutions is often critical for the development of highly efficient and reliable products and tools, as well as for ensuring a high quality of life. In fact, it is difficult to find an industry where filters do not play an important role. A car, for example, contains filters for transmission fluid, fuel, engine air, cabin air, coolant, and brake fluid. Furthermore, the quality of our drinking water, the treatment of wastewater, and the air we breathe all depend critically on filtration solutions. The filtration and purification business is expanding greatly, with scores of large companies and thousands of SMEs competing fiercely to develop better filters. Industrial demand for innovative filtration solutions is growing rapidly, along with a more intensive usage of Computer Aided Engineering (CAE) in filter design processes. Comprehensive mathematical studies need to be carried out to provide engineers with proper CAE tools and approaches. The solid-liquid and solid-gas separation processes discussed in this chapter are intrinsically multiscale, multiphysics processes. Dust particle and pore size in filter media may vary from the sub-micron scale to hundreds of microns, while a filter element may range from several centimeters to several meters in size. Depending on the operating conditions and the material properties, the filter media may behave as a rigid body or be deformable. This chapter provides an overview of the industrial and mathematical challenges in modeling and simulating filtration processes, along with a summary of the basic achievements of the Fraunhofer ITWM in this area. Approaches for the microscale (pore scale) and macroscale (filter element scale) investigation of filtration processes are discussed in detail, along with a recently developed method for treating the coupled multiscale filtration problem. Software tools developed in the last decade are described. Finally, some success stories are presented to illustrate the potential of industrial mathematics for solving practical problems.