Experimental investigation on explosion characteristics of nano-aluminum powder–air mixtures

Explosion characteristics of nano-aluminum powders with particle sizes of 35, 75, and 100 nm are investigated in a 20-liters spherical explosion chamber. Results show that the maximum explosion pressure and the maximum rate of pressure rise mainly depend on the dust concentration. For dust concentrations below 1000 g/m$^3$, the maximum explosion pressure increases gradually to a maximum value with increasing dust concentration. After the dust concentration increases above 1250 g/m$^3$, the maximum explosion pressure starts to decrease. The trends of the maximum rate of pressure rise follow the same pattern with increasing dust concentration. The lower explosion concentration limits of nano-aluminum powders with sizes of 35, 75, and 100 nm are found to be 5, 10, and 10 g/m$^3$, respectively, while the lower explosion concentration limit of ordinary aluminum powders is about 50 g/m$^3$.