On optimization of pleat packing density in a pleated membrane filter

Pleated membrane filters are widely used to remove undesired impurities from a fluid. A filter membrane is sandwiched between porous support layers, then pleated and packed into an annular cylindrical cartridge with a central hollow duct for outflow. While this arrangement offers a high ratio of surface filtration area to volume, the filter performance is not as efficient as a flat filter with the same surface area. This stems from several possible hypotheses including additional resistance from the packing density of the pleats, the complex flow within the pleated membrane, and possible damage of the membrane during the pleating process. In this work, we present a model to investigate the effects of axial variations of the 3D filter cartridge. We also introduce a more detailed description of the geometry that accounts for the cylinder's curvature. Using asymptotic methods to simplify the flow throughout the cartridge makes it possible to investigate how the number of pleats or pleat packing density affects the performance of pleated membrane filters, where the ultimate goal of this study will be to find an optimal number of pleats to achieve optimum filtration performance.