Experimental study on suppression of gas and coal dust explosion by powder clouds

In order to explore prevention and control measures for gas and coal dust explosionꎬ explosion ̄ proof performance of powder clouds is tested in roadways with large ̄scale sections. Firstlyꎬ an 2 m large pipe and its open space were used to study formation process and dynamic distribution characteristics of powder clouds. On this basisꎬ with explosion pressure and flame velocity as characteristic parametersꎬ gas and coal dust explosion and suppression experiments were conducted in a large roadway with a section of 7􀆰 2 m . The results show that the powder can cover 7􀆰 4 m section at 60 msꎬ and most of the powder is ejected at 1 200 msꎬ forming an effective explosion ̄proof barrier. When surface density of powder cloud reaches 8􀆰 1 kg / mꎬ flame can be completely extinguished within 13 mꎬ and maximum explosion pressure is reduced by 57􀆰 0% from 0􀆰 293 to 0􀆰 126 MPa while pressure rising time at 140 m is delayed by 137 ms. As power concentration increasesꎬ suppression effect of cloud curtain is enhancedꎬ and it can extinguish 第 3 期 黄子超等: 粉体云幕对瓦斯煤尘爆炸隔爆效果的试验研究 flame in a short distance and greatly attenuate explosion pressure.