Switching mechanism and optimisation research on a pressure-attitude adaptive adjusting coal seam water jet slotter  

作　　者：Yiyu Lu Yangkai Zhang Jiren Tang Qi Yao 

机构地区：[1]State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 400044,China [2]School of Resources and Safety Engineering,Chongqing University,Chongqing 400030,China

出　　处：《International Journal of Mining Science and Technology》2022年第6期1167-1179,共13页矿业科学技术学报（英文版）

基　　金：supported by the National Natural Science Foundation Outstanding Youth Fund(No.51625401);the Chongqing Natural Science Foundation(No.cstc2018jcyjAX0542);the Program for Changjiang Scholars and Innovative Research Team in Chongqing University(No.IRT17R112).

摘　　要：To investigate the attitude-switching mechanisms of existing jet slotters,which integrate drilling,punching and slotting operations,and to improve its fracture ability,we used the power bond diagram theory to analyse the dynamic flow pressure,and force of slotters.A mathematical model was developed for the dynamic characteristics of slotter systems.Furthermore,to study the effect of the main characteristic parameters on the ability of the nozzle to erode sandstone,multi-orthogonal experiments were carried out.And the optimised slots were applied in later practical operations.The research results show that the inlet fluid passed through the time-varying orifice to generate pressure differential thrust,which overcame the spring force,pushed the valve core to open the side nozzle,and closed the rear cavity channel thereby realising the switch of the slotter attitude.An optimal plan was established to balance the diameter,depth,and volume of punching,and a rock-breaking plan was developed for the slotter.Subsequently,the optimised water jet slotter was practically used in coal seam gas drainage.Compared with conventional dense drilling,water jet slotting technology significantly improves the ability,efficiency,and effect of increasing the permeability of the coal seam.

关 键 词：Gas drainage Water jet slotting Pressure-attitude adaptive adjustment Power bond diagram Multi-index orthogonal test Gas drainage practice 

分 类 号：TD712.6[矿业工程—矿井通风与安全]