Effect of particle shape on void fraction

Void fraction and bulk density are the fundamental characteristics of most practical analyses of particulate materials. Most industrial particles are not spherical and can have various shapes. In this study, the effect of particle shape on the free and tapped void fractions was tested. Based on the analysis of well-defined geometries, high circularities was considered equivalent to sphericity. All the experiments conducted with a high Archimedes number (Ar), where the Ar effect was negligible, demonstrated that three trend lines were obtained as a function of sphericity for long, flat, and high-sphericity particles. Two factors can be defined by dividing the void fractions of the non-spherical particles by that of spherical particles, namely, the shape and Ar factors. Accordingly, the void fractions are calculated and predicted to be within ±5% for free void fractions and ± 7% for tapped void fractions.