Investigation of a Self-Excited Pulsed Water Jet for Rock Cross-Cutting to Uncover Coal
LU Yi-yu
GE Zhao-long
LI Xiao-hong
CHEN Jiu-fu
LIU Yong
Abstract：Safe production and procedures at the driving face are restricted in mines of south-west China by the long periods required for uncovering coal by rock cross-cuts.A new idea is proposed to solve this problem using self-excited oscillations of pulsed water jets.This is pro-posed to improve the permeability of the seam and increase the gas desorption rate,which will shorten the cycle of rock cross-cutting and coal uncovering.The properties of a self-excited os-cillating pulsed water jet were studied.The hydraulic parameters of the jet and the nozzle structure were optimized by investigating how pump pressure and flow rate effect the depth and width of slotting.Application at the Fengchun coal mine shows that the jet may penetrate 1.5m or more into the coal seam and that the gas desorption rate increases by 4.4 times.Produc-tion efficiencv is increased by reducing the number of holes drilled(by 60%)and reducing the construction period for uncovering cross-cut coal by more than 70 days.
Keywords：self-excited pulsed water jetslottingrock cross-cut coal uncovering
Publication Date：2010-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 55-58,69 )