高瓦斯综放面顺层钻孔二次封孔优化设计研究

Optimum Design of Secondary Sealing for Bed Drilling in Fully Mechanized Caving Face with High Gas Content

针对伯方煤矿3211综放面赋存情况,实测分析了原封孔工艺抽采效果,显示原工艺封孔效果较差,初始抽采浓度低、抽采浓度衰减快、抽采时间短和瓦斯浓度变化异常;根据二次封孔技术的原理,研究了改进型二次封孔技术,确定了封孔深度16m,一次封孔长度8m,粉料腔室长度7m,实测结果显示改进型二次封孔技术所封钻孔在平均单孔瓦斯抽采浓度、瓦斯抽采纯流量和平均有效抽采时间方面分别提高了10.3%,1.3L/min和22.2d,封孔效果良好。

Aiming at the occurrence of 3211 fully mechanized caving face in Bofang Coal Mine,the actual measurement and analysis of the original sealing effect show that the original sealing effect is poor,the initial extraction concentration is low,the extraction concentration decreases rapidly,the extraction time is short and the gas concentration changes abnormally.According to the principle of secondary sealing technology,the improved secondary sealing technology is studied,and the sealing depth is 16 m,the length of primary sealing is 8 m,and the powder concentration changes abnormally.The length of material chamber is 7m.The measured results show that the average single hole gas extraction concentration,gas extraction pure flow and average effective extraction time of the sealed boreholes by the improved secondary sealing technology are increased by 10.3%,1.3L/min and 22.2d,respectively.The sealing effect is good.