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目前,钻孔预抽煤层瓦斯是突出煤层回采工作面一种重要的区域防突措施。针对低透气性松软突出煤层,与退钻裸眼瓦斯抽采方式相比,采用筛管下放工艺进行瓦斯抽采具有一定的优势,但因松软煤层松软、破碎,易出现塌孔,导致筛管无法下入孔底,造成钻孔实际抽采段减少,影响瓦斯抽采效果,为煤矿的安全生产埋下隐患。为解决这一系列问题,研发了大通孔开闭式钻头,并对其结构特点及工作原理进行分析,以现场试验验证其使用效果。
At present, pre-pumping borehole gas is an important area outburst prevention measure that highlights the coal mining face. Compared with the unobstructed open-hole gas drainage method, the low-gas-permeable and soft outburst coal seam has some advantages compared with the unworked open-hole gas drainage method. However, because the soft and soft coal seam is loose and broken, Under the hole into the bottom, resulting in the actual drilling section to reduce the impact of gas extraction effect, laying a hidden danger for the safety of coal mines. In order to solve this series of problems, we have developed a large open-hole drill bit, and analyzed its structural features and working principle, and verified the use effect by field test.