气动式底板钻机多相耦合排渣机理及应用

Multiphase Coupling Deslagging Mechanism and Application of Pneumatic Floor Drilling Machine

针对气动式钻机在煤矿巷道底板排渣效率低、成孔困难的问题,基于两相流态变化进行了气-液-固多相耦合排渣机理分析,并从钻渣运移动力路径的角度对成孔困难原因进行阐释。结果表明:在底板水影响下,孔内先后经历“静态-泡状流-段塞流-环空雾流”等两相流态,约75%的钻渣在泡状流与段塞流阶段以较快速率排出,剩余钻渣需在环空雾流阶段以较低效率缓慢排出;底板水侵蚀引发的孔口外扩是成孔困难的主要原因。结合益新煤矿-250机道石门底板锚固工程实际,提出了“套管束流”排渣法并优化了原钻孔工艺,现场应用效果良好。

In view of low slag discharge efficiency and hole-forming difficulty problem of pneumatic drilling machine in coal mine roadway floor,multiphase flow pattern change in drill-hole during slag discharge process has been analyzed based on two-phase flow pattern change.Meanwhile,reasons that cause hole-forming difficulty have been analyzed from the point of moving force path of drilling slag.The results show that two-phase pattern change,such as“static-bubble flow-slug flow-annular fog flow”were successively experienced in the hole,about 75%of drilling slag is discharged at a faster rate during the bubble and slug flow stages,while the remaining drilling slag should be discharged slowly in the stage of annular fog flow with low efficiency;external expansion of drill-hole caused by water erosion is the main factor leading to drilling failure.Based on the engineering practice of-250 cross-hole in Yixin Coal Mine,the“casing beam”deslagging method is proposed correspondingly and the original drilling technique is optimized,and the field application effect is good.