Abstract：To evaluate the potential risk of coal dust, master how the concentration and ignition delay time effected the minimum ignition combustion, the Hartmann tube was used to study the effect of comcentration and ignition delay time on the minimum ignition energy. The results show that ror 54 μm pulverized coal,with the concentration increasing,pulverized coal minimum ignition energy decreases first and then increases, existing the best concentration 750 g/m~3. When the concentration is 750 g/m³, with the extension of time,which also decreases and then increases,existing the best ignition delay time 90 ms.

Keywords: ignition time; pulverized coal; minimum ignition energy; Hartmann tube