Flow and fouling in multi-layered membrane filters

Multi-layer membrane filters, which consist of several thin porous membranes with different properties (such as pore size and void fraction) stacked on top of each other, are widely used in industrial applications to remove contaminants and undesired impurities (particles) from a solvent. It has been experimentally observed that the performance of well-designed multilayer structured membranes are markedly better than those of equivalent homogeneous membranes. Mathematical characterization and modeling of multi-layer membranes can help our understanding of how the properties of each layer affect the performance of the overall membrane stack. We present a simplified mathematical model to describe how the microscopic properties of a multi-layer membrane affect the overall filter performance.