Inhibitory effects of typical inert gases on the flame propagation and structures in TiH2 dust clouds

Abstract

The inhibitory effects of CO2, N2 and Ar on TiH2 dust explosion had been experimentally studied. The results showed that the inhibitory effects of the three inert gases on the flame morphology, propagation velocity and temperature of TiH2 dust explosion were in the order of CO2 > N2 > Ar under the same oxygen concentration. CO2 accelerated the cooling and extinguishing processes of the incomplete burning particles to inhibit the further dehydrogenation and combustion reactions of TiH2 particles. N2 reacted with TiH2 particles and form ternary Ti-O-N solutions on its surface to hinder the binding progress of TiH2 and O2. In the process of Ar dilution, OH radical was adsorbed on the surface of TiH2-x to enhance its surface reactivity. N2 and CO2 mainly inhibited the explosion of TiH2 dust cloud through dilution of O2, cooling and chemical reactions, whereas Ar mainly played the roles of diluting O2 and cooling.