穿层钻孔施工用三防装置的改进与应用

Improvement and Application of Three Prevention Device for Drilling Construction through Layers

针对穿层钻孔施工使用的三防装置密封效果不佳、安装困难、防喷能力不足的问题,通过调研施工现场的钻机、煤层地质、钻孔工艺、现用装备等因素,采用锥形套管和两半式密封圈+开口密封圈相结合的综合密封结构,提高了钻孔孔壁与孔口套管外壁、三棱钻杆与密封圈等关键部位的密封效果;研制了联接支架,用来安装孔口密封装置,降低了劳动强度;在现用水渣分离箱上增加了可伸缩囊袋,实现了在不增加体积的前提下满足防喷能力要求。经现场试验,改进的三防装置总尘除尘效率达到93.5%~90.4%,呼吸性粉尘除尘效率达到76.4%~81.3%,钻机下风侧最高瓦斯浓度由0.8%下降到0.24%,取得了明显的效果。

Aiming at the problems of poor sealing effect,difficult installation and insufficient spray prevention ability of the three prevention device for the drilling construction through layers,through research on factors such as drilling rigs,coal seam geology,drilling technology and current equipment at the construction site,an innovative comprehensive sealing structure of conical casing and two half sealing rings+open sealing rings was adopted to improve the sealing effect of key parts such as the drilling hole wall and the outer wall of the borehole casing,as well as the triangular drill rod and sealing ring;developed a connecting bracket to install the hole sealing device and reduced labor intensity;expandable bag was added to the water residue separation box,which meets the requirements for spray prevention without increasing volume.After on-site testing,the improved three prevention device achieves a total dust removal efficiency of 93.5%to 90.4%and a respiratory dust removal efficiency of 76.4%to 81.3%,and the gas concentration on the downwind side of the drilling rig reduces from 0.8%to 0.24%,which achieves significant results.