Development of pressure evolution modeling for the combustion of distinct metal dust morphologies

Abstract

Combustible dust explosions continue to present a significant hazard toward industries processing, storing, or pneumatically conveying metal dusts. Recent experimental investigations performed in a Siwek 20 L sphere combustion chamber characterized the explosion severity as a function of variable aluminum particle morphology (spherical, irregular granular, and flake aluminum powder). Contained ignition of suspended particulates with increasing surface irregularity exhibited a distinct rise in deflagration severity – in this work, fuel reactivity was modeled as a means of predicting hazard potential for distinct metal dust processing methods. Applying the shrinking particle theory with reaction and species diffusion limitations, previously reported pressure evolution outcomes were verified through development and implementation of closed-vessel mathematical modeling based on derivation of fundamental mass and thermal balance equations. Geometric equivalence methods were employed to estimate particle diameter for irregular dust morphologies. The consequence prediction models are in good agreement with experimental data sets; all relevant deviations are examined in detail.