Minimum ignition temperatures and explosion characteristics of micron-sized aluminium powder

Abstract

To forestall, control, and mitigate the detrimental effects of aluminium dust, a 20-L near-spherical dust explosion experimental system and an HY16429 type dust-cloud ignition temperature test device were employed to explore the explosion characteristics of micron-sized aluminium powder under different ignition energies, dust particle sizes, and dust cloud concentration (Cdust) values; the minimum ignition temperature (MIT) values of aluminium powder under different dust particle sizes and Cdust were also examined. Flame images at different times were photographed by a high-speed camera. Results revealed that under similar dust-cloud concentrations and with dust particle size increasing from 42.89 to 141.70 μm, the MIT of aluminium powder increased. Under various Cdust values, the MIT of aluminium dust clouds attained peak value when concentrations enhanced. Furthermore, the increase of ignition energy contributed to the increase of the explosion pressure (Pex) and the rate of explosion pressure rise [(dP/dt)ex]. When dust particle size was augmented gradually, the Pex and (dP/dt)ex attenuated. Decreasing particle size lowered both the most violent explosion concentration and explosive limits.