N00工法是一种节约资源并能降低开采成本的长壁采煤工法,快速无伤定向切割顶板岩石使采空区顶板垮落是该工法的关键。基于水射流理论与技术,提出了利用磨料射流定向切割顶板的新思路,研究了磨料射流定向切顶系统的结构组成及工作原理,设计了水射流喷嘴、切割喷头、定向器、输送机、磨料供给系统等关键部件的结构与尺寸,实验优化了磨料射流定向切顶的最优工作参数,并于陕西某矿S1201-II工作面进行了顶板切割试验。结果表明,在射流压力25MPa,喷嘴直径1.5mm,磨料类型黄沙/石英砂,磨料浓度3.5%,切割速度4.4mm/s条件下,系统可在1个循环时间(50min)、1个步距(840mm)范围内对7000-8000mm长度的4孔同步定向切缝,实现对留巷顶板的快速高效定向切割。

The N00 method is a highly efficient and resource saving mining method, witch a key step is to quickly separate the gob roof and the roadway roof by making a slit between them. Based on the water jet theory and technology, a new idea of using abrasive jet directional cutting roof is proposed. The structural composition and working principle of the abrasive jet directional cutting system are studied, and the water jet nozzle, cutting nozzle, orienter, conveyor, abrasive are designed. Through experiment, the working parameters of the abrasive jet directional cutting has been optimized, and the roof cutting test was carried out on the S1201-II working face of a mine in Shaanxi. The results show that under the conditions of jet pressure 25MPa, nozzle diameter 1.5mm, abrasive type yellow sand / quartz sand, abrasive concentration 3.5%, cutting speed 4.4mm / s, the developed system is able to make slits at the same time in 4 holes of 7000-8000mm deep within a cycle time (50min).

TD 431

长江学者和创新团队发展计划资助项目(IRT17R112)