A relation for the void fraction of randomly packed particle beds

A.C. Hoffmann and H.J. Finkers
Dept. of Chemical Engineering, University of Groningen, Nijenborgh 4
9747 AG Groningen, The Netherlands

Abstract
The void fractions of loosely packed and tapped beds of particles of continuous size distributions are correlated by means of a new semi-empirical relation proposed. In this relation four parameters describing the following particle properties are included: i) the mean particle size, ii) the spread of the particle size distribution, iii) the particle density and iv) the particle shape.

The adjustable constants in the relation were optimised using experimental void fractions and particle characteristics for a wide variety of powders mainly gathered from the published literature. The optimised relation correlated the loosely packed and tapped bed void fractions with correlation coefficients of 0.955 and 0.973 respectively, the correlation thus removing virtually all the scatter in the original data. A discussion is provided.