Abstract:
In order to solve the problems such as high density of gas drainage hole, small influence range of single hole drainage, little amount of drainage, frequent carrying of drilling rig and low working efficiency, using high pressure combined water jet technology, we optimize the design of front and back nozzles and steering gear. On the basis of the axial hole, the technology of multiple radial branch holes extraction is realized. The results of the study show that with multi-combination high-pressure nozzle and hose combined with coal rock breaking and small radius turning of steering device, the dynamic kinetic energy load is applied to the coal body to realize dynamic damage and fracture of coal and rock mass, and the gas permeability of coal seam can be rapidly improved.