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89 triple drill bit is installed at the bottom of the drill pipe, the top of the drill bit is inlaid with alloy, which is convenient for drilling the drill pipe. There are two nozzles on both sides of the barrel of the drill bit, the diameter of the nozzles is 1.6~3.0mm earlier, and the annular gas nozzles are installed around the nozzles to ensure coaxial injection of slurry. Three single nozzles are installed on the tool body to spray high pressure water. For some soft geological structures to the end, no need to replace the drill, can be slowly lift rotary jet, improve work efficiency.