Design criteria of blade shape filter material for graded cohesion less bases

Abstract

The paper presents a study on development of filter design criteria based on controlling constriction pore size of non-spherical, non-uniform filter material for graded cohesion less base. It is a deviation from the existing design criteria of protective filters which are mostly based on the certain particle size ratios of filter and base materials and consider the shape of the particles of filter material as spherical. Some studies were carried out earlier on the non-uniform filter material size, but there also the particles have been considered as spherical in shape. To ascertain the effect of shape of the non-uniform filter material on the design criteria of protective filters, the blade-shaped non-uniform filter material was used in the present study. Based on this study, it was observed that the criteria developed for non-uniform filter material particles considering the particle shape as spherical do not hold good for non-spherical shapes of the filter material. The blade-shaped filter material used in the present study was found to protect even finer bases than what was suggested by most of the existing criteria which were based on spherical shape filter material.