Application of Water Jet Assisted Drilling and Slotting Technology in Top Coal Softening and Gas Drainage
It is the results of the field trials of high pressure water jet assisted drilling with slotting and benchmark monitoring of conventional rotary drilling without slotting at the Chenjiashan Mine that are analyzed. The field trials followed the previously trial using high pressure water infusion to soften the top coal for block caving longwall face conducted at the Chennjiashan Mine. The monitoring program was aimed at determining the benefit of water jet assisted drilling in terms of increasing in borehole depth and gas drainage efficiency due to low torque and thrust required, opening the bore wall cleats by water jets, and slotting for top coal softening of longwall face. The field trials utilized the underground HP water pump with 200l/min flow rate at pressure of 45MPa, high pressure drill rods of 63.5mm in diameter, high pressure water jet assisted drill bits, MK-5 drill rig and high pressure water swivel with seal pressure of 130MPa. The depth of slots achieved are about 600mm each side and the drilling rate is increased up to 30％ with high pressure water jet assisted drilling. In additional to the field trials, a series of laboratory tests were also conducted to determine the water pressure required for deep slotting and to optimize the jet nozzles. The depth of slotting achieved in laboratory tests was above 740mm.
coal mining mining safety water jet assisted drilling top coal softening gas drainage
LIU Yuzhou LU Tingkan
School of Safety Science and Engineering, Henan Polytechnic University, Jiaozuo 454000, Henan, China School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo 454000, Henan, China
国际会议
The 2007 International Symposium on Safety Science and Technology(2007采矿科学与安全技术国际学术会议)
河南焦作
英文
1448-1452
2007-04-17（万方平台首次上网日期，不代表论文的发表时间）