METHOD AND APPARATUS OF ABRASIVE JET TYPE UNDERWATER CUTTING

PURPOSE:To improve cutting operability in a deep underwater depth with high speed fluid containing fluid having abrasive grains floated in a medium having viscosity larger than water when the high speed fluid containing the abrasive grains is jetted to an object in the water to cut the object. CONSTITUTION:Slurry containing abrasives in an underwater slurry tank 7 connected through a hose 13 to a slurry supply device 6 provided on the water are boosted by a pump 6 to be supplied to a nozzle 1 disposed in a nozzle shifting device 2. While the nozzle 1 is shifted along the peripheral surface of an object to be cut, the slurry (high speed fluid) mixed with high pressure water supplied from a super-high pressure pump 3 is jetted from the tip of the nozzle to cut the object. Then, the high speed fluid contains fluid having the abrasive grains floated in a medium having viscosity larger than water, for example high polymer solution to facilitate the grasp of cutting situation even during cutting operation in a deep depth of poor visibility.