Efficient Gas Drainage Technology of High Level Suction Roadway at Fully Mechanized Caving Face in High Gas Single Thick Coal Seam

Aiming at the actual conditions of No.3 coal seam of Yuwu Coal Mine, using combined method of theoretical calculation, similar material and numerica simulation, the rationally designed position was analyzed. The pre-pumping gas experiment was carried out at N1102 face. The 550 drilling holes extracted 8 683 200 m³ gas in 450 d. During the goaf gas extraction experiment of high level suction roadway at N1102 working surface, the pure extraction amount reached 9.94 m³/min. The results indicate that the high level suction roadway extraction way based on down holes drainage is a high efficient extraction technology. This technology could not only solve the large gas emission and the transfinite gas amount in the upper corner, but also it could speed up coal roadway driving and ease the difficult cohesion tension problem in mining, drilling and extracting.