| 摘要 |
PURPOSE:To perforate a high temperature wall body without separating cutting edges by injecting low temperature nitrogen gas from in a core cutter and cooling the cutting edges of the core cutter. CONSTITUTION:Nitrogen gas with a pressure 5kg/cm<2> is supplied from a nitrogen gas cylinder 2 to a core cutter 10 through a control valve 6. At this time the tip temperature of the core cutter is cooled at -20 deg.C to +20 deg.C. The valve 6 is opened, low temperature nitrogen gas is supplied to the core cutter 10, a motor 12 is rotated in a state where cutting edges 26 are cooled and a high temperature wall body 14 in contact with the cutter is perforated. Though the cutting edges 26 are heated by the heat from the high temperature wall body 14, the cutting edges are cooled through grooves and are not separated. |
