钻孔中煤体割缝的高压水射流装置设计及试验

本文针对矿井煤层瓦斯抽放及防突中煤层透气性差，瓦斯抽放率低等问题，按照高压水射流技术应用的原理，设计了应用于抽放钻孔中切割煤体的高压水射击流装置，并在现场对喷嘴和射流器进行了试验。试验结果表明，水射流方向采用+100，喷嘴直径为1.5mm，切割速度为0.2m/min，泵压为30MPa时，水射流切割钻孔中煤体效果最佳；煤层采用高压水射流切割缝后，钻孔预抽瓦斯的抽放率提高了18.8%，抽放时间相对缩短90%以上。因此，该项技术对于煤层瓦斯抽放和防治煤与瓦斯突出具有重要作用。

Design and experimentation of high-pressure water jet set applied to incising coal seam in boreholes

In allusion to the problems of the low gas-penetration and low ratio of gas drainage during draining gas and prevention outburst,it is designed the high-pressure water jet installation of cutting coal which is installed in the draining bore,and tested the nozzle and the ejector in scene.The result showed that the effect of the coal cut by high-pressure water jet is the best when the angle of water jet is +100,the diameter of nozzle is 1.5mm,the cutting speed is 0.2m/min and the pressure of the pump is 30MPa;it is showed that the draining ratio is raised about 18.8% and the draining time is shorten over 90% when the coal is cut by the high-pressure water jet,too.Therefore,the technology is very important to the draining gas and preventing outburst.