STUDIES ON THE LOWER EXPLOSION LIMIT OF COAL DUST CLOUDS. PART 1: SIMULATION AND COMPARISON OF CALCULATED AND EXPERIMENTAL RESULTS.

On the basis of findings by Howard and Essenhigh a new model for coal dust explosion propagation was developed to simulate the ignition and combustion phenomena of single particles at the early stage of the initiation of explosion near the lower explosion limit condition. The ignition energy is given to a particle and ignition occurs by the heterogeneous reaction. It is defined that explosion occurs when the adjacent particles are ignited by the heat from the burning particle. Thermal ignition theory was used to define the heterogeneous ignition of the adjacent particles. Lower explosion limit concentrations of coal dusts were also measured. An apparatus used to generate uniform dust clouds was the one developed by Ishihama. That is a tapping sieve method. Comparison of calculated and experimental results showed very good agreement. The adequacy of the model was discussed as well.