Effect of single-layer wire mesh on premixed methane/air flame dynamics in a closed pipe

Abstract

In order to explore methods for suppressing methane combustion and improve the safety of its engineering application. The effect of single-layer wire mesh on premixed methane-air flame behaviors and pressure dynamics in a closed pipe is experimentally investigated. Premixed methane-air mixture with stoichiometric ratio is used in our experiments. The wire mesh of seven different types are chosen. High-speed schlieren photography system and pressure transducers are adopted to record flame behaviors and pressure-time history, respectively. It is found that the flame can easily pass through the wire mesh of 12 and 20 mesh, but extinguishes under the effect of 30 mesh. For 40, 60, 80, and 100 mesh conditions, the flame presents salient quenching trend but finally passes through wire mesh. Meanwhile, the wire mesh has been seriously destroyed. The results indicate that anti-destructive is quite important for the fire resistance capacity of wire mesh. Moreover, the wire mesh significantly advances tulip flame formation time and makes flame front inversion extent weaker due to its effect on advancing and weakening the interactions between flame front and pressure waves. Furthermore, almost no suppression effect on flame tip speed is observed in the upstream pipe because the reduction of gas flow velocity is counteracted by the growth of gas combustion velocity. However, the flame propagation in the middle suppression section is significantly inhibited due to the great heat losses when touching wire mesh. Besides, the maximum pressure is decayed significantly. And the suppression effect is pretty enhanced as mesh of wire mesh increases.