Effect of N2 inerting on the inhibition of methane explosions by a multicomponent powder

Abstract

To inhibit methane explosions, a new formulation for a multicomponent powder was proposed, and nitrogen (N2) was used to enhance its inhibiting effect. Experiments on explosion inhibition were conducted in a 20 L spherical vessel. The synergistic inhibition mechanism of the multicomponent powder and N2 were investigated. The results indicated that synergistic inhibition by the N2/multicomponent powder combination was greater than that of N2 or the multicomponent powder alone. With the addition of 8 % N2, the amount of multicomponent powder for complete inhibition dropped from 600 to 350 g/m3. Flame propagation and radical production by methane explosions were further reduced by N2 addition. The multicomponent powder absorbed C-containing radicals during methane explosions; this effect was weakened by N2 inerting, which was mainly attributed to the reduction in explosion energy. Based on the reaction kinetics, we concluded that for the synergistic system, the explosion energy and combustion reaction rate were mainly affected by the powder, while the flame propagation and radical production rate were mainly affected by N2 inerting. This study revealed the mechanisms for the inhibition of methane explosions by various N2/multi-component powder concentrations and proportions.