Explosion characteristics of nano-aluminum powder–air mixtures in 20 L spherical vessels

Using 20 L spherical explosion vessel, the explosion characteristics of nano-aluminum powders with different sizes were investigated. Compared with micro-scale aluminum powders explosion, nano-powders explosion processes and mechanisms were analyzed based on the auxiliary analysis of scanning electron microscopy (SEM) and X-Ray diffraction (XRD). The results show that the maximum explosion pressure and maximum rate of pressure rise mainly depended on the dust concentrations. With the increasing of dust concentration, the maximum explosion pressure increases gradually to the maximum when the dust concentrations below 1000 g/m 3 and then the maximum explosion pressure decreased especially for the dust concentrations higher about 1250 g/m 3. At the same time, the trends of maximum rate of pressure rise performed the similar rules with the dust concentrations. For the selected nano-powders, particle size change seems no obvious explosion differences. However, for micro-sized aluminum powders, explosion characteristic presents decreased change rules with the particle size increase. At the same time, the lower explosion concentration limits of aluminum powders explosion were measured and presented. Research result may have important implications for nano-sized aluminum powders utilization and safety operation. In this paper, 20 L spherical explosion vessel was used to investigate on the explosion characteristics of nano-aluminum powders of nano-scale and micro-scale ranges. The effect of dust concentration, particle size and ignition energy on the explosion characteristics were analyzed systemically. [Display omitted] ► 20 L spherical explosion vessel was used to investigate on aluminum powders explosion characteristics. ► The explosion characteristics of nano-scale powders are great different from that of micro-scale ones'. ► Dust concentrations and particle size have significant influence on aluminum powders explosion characteristics. ► The lower explosion concentration limits of nano-powders are great lower than that of micro-scale powders'.