Effects of Moisture Content on the Minimum Explosible Concentration of Aluminum Powder and the Related Mechanism

Abstract

Aluminum powder has been widely applied to various industries. However, its high activity and high burn rate can cause serious explosion risks. Many factors affecting the explosion of aluminum powder have been determined, yet moisture content has not been included. In the present work, the minimum explosible concentrations of aluminum powders with different moisture contents were measured with a 20-liter explosion test apparatus using the explosion accident in Kunshan, China, as a study case. The experimental results suggest that the minimum explosible concentration of aluminum powder dramatically increases with the increase of its moisture content first and the increasing trend becomes slower as the moisture content further increased. The oxidation time has no significant effects on the minimum explosible concentration of aluminum power in 8 hours at room temperature. Further investigation suggests that the moisture lowers the explosion risk of aluminum powder by altering its surface oxide film, ignition, and combustion process. The low contents of moisture in the range of 0%-8% increase the minimum explosible concentration of aluminum powder by inhibiting the reaction kinetics and particle agglomeration, while high contents of moistures in the range of 8%-20% affect the minimum explosible concentration by the endothermic effect and oxygen dilution effect.

Phase stability and microstructural properties of high entropy alloy reinforced aluminium matrix composites consolidated via spark plasma sintering

“…3 (a) shows that the powder consists of smooth-surface spherical microparticles that are well-dispersed. A similar aluminium powder micrograph with well-dispersed microparticles was reported by Chen et al [ 40 ]. From the SEM micrograph of the milled HEA shown in Fig.…”

Explosion Severity of Rice Dust in a Spherical System

“…6 shows a congruent trend for dried rice, in which dried brown rice with the lowest moisture content (6.0 wt %) gave the highest explosion pressure at 18.9 bar, while Bario dried rice with the highest moisture content (9.0 wt %) recorded the lowest explosion pressure (11.1 bar), demonstrating the moisture content effect on the maximum overpressure development. Moisture could induce the agglomeration of dust particles, increase the dust effective particle size, and weaken the dust cloud dispersion [24][25][26][27]. The result is a significant reduction in blast severity and dust combustibility for white rice, black rice, and Bario rice.…”