A normal distribution-based approach to evaluate the effect of dispersion pressure on the minimum ignition temperature of dust clouds

The minimum ignition temperature of dust clouds (MITC) represents a critical hazard parameter in preventing dust explosions. This study employed the Godbert-Greenwald furnace (G-G furnace) and high-speed camera to investigate the minimum ignition temperature of dust clouds (MITC) of lycopodium, corn starch, and Australian coal dust under various dispersion pressures. The distribution of dust mass falling from an unheated G-G furnace was analyzed using a normal distribution method to assess the influence of dispersion pressure on the ignition temperature of dust clouds. Furthermore, the dust's flammable limit concentration (FLC) was calculated and compared with the minimum explosive concentration (MEC) of a 20-L apparatus. The findings reveal that as the dispersion pressure decreased, the MITC of lycopodium and corn starch increased by 220 and 80 °C, respectively. Conversely, no notable change was observed in the MITC of Australian coal dust. Compared to 0.05 barg, the flame propagation speeds of lycopodium, corn starch, and Australian coal dust exhibited a notable increase of 4.17, 2.95, and 2.11 m/s, respectively, at 0.5 barg of dispersion pressure. The discrepancies between the FLC and the MEC can be attributed to variations in the ignition sources and the presence of a dust disperser.