A NOVEL APPROACH FOR CUTTING OF SUBMERGED OBJECTS:

ABRASIVE SUSPENSION JET ENHANCED BY VENTILATION

抄録

Focused on cutting of submerged objects an experiment investigation is performed on the cutting ability of water abrasive suspension jets (WASJs) under different working conditions. An in-house WASJ device with working pressure of 30MPa is used for experiments and the abrasive weight concentration is set to be 22.5 % approximately. The processing ability of the WASJ system is evaluated by cutting tests of aluminum alloy specimen both in-air and underwater conditions. Under submerged condition cutting tests are conducted by ventilating to the WASJ at different flowrates. Experimental results show that the kerf depth of air-ventilated WASJs depends on the standoff distance of cutting object and varies greatly with the ventilation flowrate. When the ventilation flowrate is increased to the range of 60~90 L/min the kerf depth of submerged cutting reaches to its maximum. Within the area of X/d 36 the relative kerf depth reaches to 1.0 and the cutting ability of air-ventilated WASJs is enhanced to the same level as that in atmospheric condition. The effectiveness of air-ventilation to submerged WASJ on its cutting performance is verified. Therefor, the feasibility to apply WASJs to dismantling of radiological structures of nuclear power plant under submerged environment is demonstrated.