瓦斯抽采孔离心式机械造穴增透机制及装备研发

Research on centrifugal mechanical cavitation and permeability improving mechanism for gas extraction hole and equipment development

目前瓦斯抽采中比较成熟的机械造穴增透装置大部分需要以高压水(气)、连杆或者液压油缸等作为驱动刀臂开合的动力,在井下长钻孔中对动力设备要求较高。研制了一款利用钻杆旋转带动产生的离心力作为打开动力的离心式机械刀,通过调节钻杆转速来控制刀臂打开角度;根据初步试验及力学数值模拟分析,针对刀具整体结构、内部齿条、轴销、刀臂等薄弱部位材质进行优化。在山西某矿N1100回风巷进行了工业性试验,对比机械造穴和水力造穴施工时间及抽采纯量,验证了离心式机械刀结构设计的合理性和可靠性。结果表明:机械造穴试验孔达到了良好的造穴及抽采效果,该装备能够降低瓦斯抽采孔造穴增透对高压设备的依赖,单穴作业时间较水力造穴缩短近1/2,瓦斯抽采量提高了1.67倍。

At present,most of the mature mechanical cavitation permeability improving devices in gas extraction need to use highpressure water(gas),connecting rod or hydraulic cylinder as the power to drive the opening and closing of the knife arm,which requires higher power equipment in long boreholes.This paper develops a centrifugal mechanical knife which uses the centrifugal force generated by the rotation of the drill pipe as the opening power,and controls the opening angle of the tool arm by adjusting the rotation speed of the drill pipe.According to the preliminary test and mechanical numerical simulation analysis,the overall structure of the tool,internal rack,shaft pin,tool arm and other weak parts are optimized.The industrial test was carried out in the N1100 return air lane of a mine in Shanxi Province,and the construction time of mechanical cavitation and hydraulic cavitation and the pure amount of extraction were compared.The mechanical cavitation test hole achieved good cavitation and extraction effect,which verified the rationality and reliability of the centrifugal mechanical knife structure design.The equipment can reduce the dependence of cavitation reflection improvement on high pressure equipment,and the operation time of single hole is shortened by nearly 1/2,and the gas extraction amount is increased by 1.67 times compared with hydraulic cavitation.