Effect of multi-component gaseous fuel on the explosion behaviors and mechanism of aluminum dust

Abstract

Hydrogen/ethylene/aluminum dust hybrid mixture may pose a potential explosion risk in the production process of triethyl aluminum. To investigate the effect of multi-component gaseous fuel on the hybrid explosion, the flame propagation behaviors and explosion characteristics of hydrogen/ethylene/aluminum dust hybrid mixtures were studied in a confined space. The explosion residues were analyzed, and the reaction mechanism was further established. The results show that the effect of hydrogen-rich fuel on increasing the maximum flame propagation velocity of two-phase fuel was more obvious than that of ethylene-rich fuel. Ethylene-rich fuel can promote the explosion intensity of aluminum dust only in an oxygen-rich environment, while hydrogen-rich fuel can promote aluminum dust explosion in both an oxygen-rich and oxygen-deficient environment. A modified formula for predicting the lower explosion limit of the hybrid mixtures is proposed, and the accuracy of the formula is significantly improved by introducing effective coefficients. The hydrogen-rich gaseous fuel mainly regulated H and OH production through R2 (H2 +O <=> H + OH) and R3 (H2 + OH <=> H + H2O) reactions to dominate the explosion reaction, while the ethylene-rich gaseous fuel affected the explosion reaction through R69 (O + CH3<=>H + CH2O) and R205 (C2H4 + M <=> H2 + C2H2 + M) reactions to regulate the degree of participation of C–C, C–H, and C–O. These results can provide corresponding reference for preventing and reducing the explosion hazard of multi-component gaseous and dust hybrid mixtures.