Inhibition evaluation of ABC powder in aluminum dust explosion.

To investigate the inhibition effect of ABC powder for 5 μm and 30 μm aluminum dust explosions, a standard 20 L spherical chamber was employed to determine the explosion severity of Al/ABC mixtures and the MIC (minimum inerting concentration) of ABC powder. Results showed that the MIC increased as the concentration of aluminum dust increased. Meanwhile, the MIC decreased with the declining particle diameter of ABC but increased with the reducing diameter of the aluminum particles. SEEP (suppressant enhanced explosion parameter) phenomenon was observed when the concentration of ABC powder was low. To reveal the enhancement mechanism of ABC powder, explosion severity of NH3 and Al/NH3 mixture was also determined. Results showed that the explosion severity of aluminum dust was significantly enhanced by adding NH3. Scanning electron microscopy showed that the particles of the explosion residues of Al/NH3 mixture and Al/ABC mixture were significantly larger than those of pure aluminum explosion residues. X-ray photoelectron spectroscopy revealed that the major explosion products of Al/NH3 mixture was Al2O3. Explosion products of Al/ABC mixture were mainly comprised of Al2O3 and P2O5. The inhibition mechanism of aluminum dust explosion by ABC powder was summarized systematically based on these results.