PERMEABILITY CHARACTERISTICS OF A SPHERICAL-PARTICLE BED BASED ON CROSS-SECTIONAL VOID-SIZE DISTRIBUTION

Based on void-size distribution over a cross section of a spherical - particle bed, permeability characteristics of bundles of tortuous tubes of non-uniform size corresponding to void spaces were investigated. The pressure drop across several kinds of bundles of tubes, where each bundle is composed of equal-sized tubes and is of different size from one another, was compared with those for uniform-sized tubes by Ergun's equation and by permeability tests. As a result, the present non-uniform model exhibits higher pressure drop than the uniform one irrespective of voidage of the bed. The experimental results were in between the two because of local voidage distribution in the radial and axial directions. These trends became conspicuous with smaller particles and narrower distributions of particle size.