Influence of particle size distribution skewness on dust explosibility

Abstract

It is well known that the particle size of dusts and powdered materials exerts a strong influence on the various phenomena involved in self-heating, ignition and explosion processes. However, it is not only the median diameter (D50) that has an influence, but also the entire particle size distribution. Nevertheless, in many cases, little importance is attached to reporting size data and only the D10, D50 and D90 percentiles of the cumulative distribution curve are given. In recent years, the polydispersity index has been proposed for characterising the particle size distribution of these materials. In the present study, data obtained in the literature have been analysed and compared to examine the effects of particle size distribution and provide guidance to researchers and practitioners in the field of dust explosions on how to report particle size distribution. This analysis indicated that the polydispersity index does not consistently correlate with explosion severity; therefore, polydispersity is not recommended for reporting particle size distribution. An alternative parameter, skewness, was analysed and the results obtained were promising, suggesting that this parameter could yield useful information about the particle size distribution curve in relation to explosion hazard characterisation.