Effect of Mean Diameter on the Explosion Characteristic of Magnesium Dusts

Abstract

-A study was carried out on the effect of particle size (mean diameter) on magnesium dust explosion. Experimental investigations were conducted in a 20-L explosion sphere, using 10 kJ chemical ignitors. Explosion tests were performed with three different dusts having mean diameter (38, 142, 567 μm) and the dust concentrations were up to 2250 g/m 3 . The lower explosion limits(LEL) of magnesium dusts were about 30 g/m 3 at 38 μm and 40 g/m 3 at 142 μm. LEL tended to increase with particle size and this means that the explosion probability of magnesium dust decreased with increase of particle size. The maximum explosion presssure (Pm) and Kst (Explosion index) decreased with the increase of particle size. For magnesium powder of 567 μm, however, the explosive properties were not observed in the 5 kJ ignition energy.