旋转射流破岩成孔规律研究

在前期对旋转射流结构特性及流动特性研究的基础上，利用试验的方法研究了射流压力、喷距、岩石的渗透率及强度、添加剂的浓度等因素对旋转射流破岩效率的影响。同时，研究了岩石渗透率对旋转射流和普通圆射流影响的区别。研究结果表明：在同喷距同射流压力条件下，破岩效果随着岩石强度的减小、岩石渗透率的增加而增加；相比而言，岩石的渗透率在射流的破碎效果中起着主要作用；在相同射流压力条件下随着添加剂浓度的增大，岩石的破碎深度、破碎直径和破碎体积都表现出增大后减小的变化趋势。本试验条件下的最优浓度为200－300mmp，随着渗透率的增大，旋转射流破岩成孔的效果明显优于普通圆射流的破岩成孔的效果。

STUDY ON ROCK DRILLING BY SWIRLING JET

Based on the previous research on structural and flow characteristics of swirling jet. the testing study is made to analyse the factors affecting rock breaking efficiency of swirling jet, such as pump pressure, jet distance, rock permeability and intensity, consistency of additive, etc. Meanwhile the distinction of the effects of rock permeability on swirling jet and straight jet is studied. The results show that rock breaking efficiency by swirling jet apparently increases with the decrease of rock strength and the increase of rock permeability at the same standoff distance and pump pressure. The rock permeability plays important role in the rock breaking effect of jet. The effect of rock permeability on the swirling jet is greater than that on the straight jet. Meanwhile the results show that the depth, diameter and volume of the hole drilled by swirling jet apparently increase at the beginning and decrease afterwards with the increase of consistency of additive. The most excellent consistency of additive is 200~300 mmp in this experiment.