关键词: 高瓦斯, 低透气性, 喷孔, 瓦斯超限, 防喷装置, 瓦斯抽采

Abstract: In order to solve the problems of drilling and spraying holes in the bottom drawway of Alpine Coal Mine, over-limit of gas, long cycle of gas control in the mine, large amount of drilling construction work, which in turn caused the tight succession of mining and excavation, etc., the company optimized and improved the blowout preventing pipe and the blowout preventing tee, the "cinder-water-gas" separating box, and developed the spiral conveying device, traveling device and power-off protection device. By optimizing and improving the blowout prevention pipe, blowout prevention tee, "cinder-water-gas" separation box, supporting the development of screw conveyor, traveling device and power failure protection device, the company has formed a high-efficiency blowout prevention device with multiple sealing and blowout prevention systems, including "orifice - blowout prevention tee - separation box", and has also combined the drilling process to propose a multiple sealing process of "orifice - blowout prevention cylinder - separation box", which has formed a completely closed and negative pressure blowout prevention system. In addition, the construction process of the fully enclosed negative pressure continuous pumping blowout preventive device has been formed, which realizes the fully enclosed management of cinder, water and gas in the process of blowout during the drilling construction, and has been tested on site in the 1907 bottom pumping lane of Gaoshan Coal Mine. The results of the field test show that: the device and its process realize the fully closed treatment of drilling slag, water and gas in the process of drilling and blowing holes, effectively controlling the gas overrun, and when blowing holes occurred in the drill holes, the maximum concentration of gas in the extraction pipeline was about 26%, and the maximum concentration of gas in the return air flow was 0.05%, and there was no overrun of gas limit, and under the premise of adopting safety measures, the continuation of drilling was guaranteed, and the feed footage The maximum drilling speed reaches 60m/shift, which is 1~1.5 times higher; the fully enclosed negative pressure continuous pumping anti-spraying device can effectively control the problem of gas overlimit, ensure the fully enclosed management of drilling slag, water and gas in the process of drilling and spraying holes, effectively control the overlimit of gas, ensure the continuity of drilling construction process, and shorten the cycle of gas management, which provides an important demonstration and leading role for the management of gas in similar mines.