Pore Flow

Pore flow refers to the volumetric flow rate passing through the individual pores of a filter medium. It is a key factor for the overall flow rate through the medium and is determined by pore geometry, the number of pores, and the pressure differential. In membrane-based processes, it is also referred to as flux or permeate flow per unit area. Flow in the pores often follows the Hagen-Poiseuille equation, according to which the volumetric flow is proportional to the fourth power of the pore radius. Small changes in pore diameter therefore have a strong impact on throughput. In practice, pores are considered as a network of channels; pore size distribution, tortuosity, and surface characteristics influence resistance. GKD designs fabrics so that pores are arranged in defined areas and pore flow ensures both high volumetric throughput and reliable particle retention. Measurement methods such as capillary flow porometry determine the pressure-flow curve and derive the mean flow pore diameter.