Suppression effect of inert gases on aluminum dust explosion

Abstract

The suppression mechanism of inert gases for 5 μm aluminum dust explosion was investigated in a confined cuboid chamber. The characteristic parameters of flame propagation and explosion severity parameters that were affected by the inert gases were systematically studied. The results indicated that the minimum inerting volume fraction of carbon dioxide was lower than that of nitrogen, thereby indicating that the suppression effect of carbon dioxide on aluminum dust explosion was superior to that of nitrogen. To reveal the suppression mechanism on a micro level, a kinetic model that considered the surface kinetic mechanism was proposed. The results revealed that as the inerting volume fraction of the inert gas increased, the heterogeneous reactions that promoted the generation of intermediate species were mostly suppressed, while the heterogeneous reactions that consumed intermediate species were facilitated. Thus, carbon dioxide and nitrogen exerted certain suppression effects on surface reactions in their characteristic ways.