Design criteria of protective filters based on particle shape and gradation parameters

摘要

This study presents design criteria of protective filters for different shapes of filter material and subsequently the effect of shape parameters of filter particles on its design. The filter-base combination tests have been conducted in the laboratory for different shapes of filter material, i.e., elliptical, sub-rounded, irregular and elongated. The shape parameters considered in the study are sphericity, shape factor, flatness ratio and elongation ratio. It was observed that the design criteria varied with the shape of filter particles even if the gradation of the filter material was similar. The design criteria in the form of empirical equations have been developed on the basis of D _(15)of filter mass, d _(85)of base, permeability ( k ) of filter mass and shape parameters of filter mass.