Dust Explosion Characteristics near the Minimum Explosible Concentration

Abstract

Minimum explosible concentrations are important safety information concerning dust explosions. This paper presents the results of numerical simulations of dust explosions under conditions close to the minimum explosible concentrations. Dust explosions are modeled as processes of combustion-wave propagation by heat conduction between particles; a particle releases heat when its temperature reaches an ignition temperature. The source term in the heat conduction equation is expressed as the summation of delta functions, enabling the evolution of temperature distribution to be given in terms of fundamental solutions （Greenʼs functions）. In cases of regularly arranged particle configurations, analytical expressions can be obtained for propagation speed and minimum explosible concentration. Numerical simulations were conducted for random particle configurations, reproducing results that are consistent with previous experiments. The influence of particle-size distribution on propagation speed and minimum explosible concentration is additionally studied.