Trajectory Analysis of Collection Mechanisms in Fibrous Bed Filtration

Abstract

Initial filter coefficients, which express the collection efficiencies of suspended particles in clean deep-bed filters, were estimated by trajectory calculations using Kuwabara's flow model in fibrous deep bed.
These calculated initial filter coefficients were correlated with five dimensionless groups as in granular deep-bed filtration, i.e. modified adhesion group, modified gravity group, interception parameter, Kuwabara's flow model parameter and retardation group for van der Waals attraction force, under conditions where double-layer repulsion forces between suspended particles and fibers were negligible and the adhesion efficiency was untiy.
In particular, these values could be estimated approximately by semiempirical correction equations under conditions where the effects of gravity settling on filtration efficiencies were negligible.
And, the more dominant the double-layer repulsion forces were against van der Waals attraction forces, as in granular deep-bed filtration, the more decreases in initial filter coefficients were observed.