| 摘要 |
<p>PURPOSE:To prevent perfectly adhesion of primary and secondary slag to a cutting slit at the time of cutting by providing nozzles for removing primary slag and a succeeding nozzle that moves with the nozzles of a cutting torch at a fixed distance on the back of a cutting slit in hot gas cutting of an extra thick steel ingot. CONSTITUTION:When gas-cutting an extra thick steel ingot at >=500 deg.C high temperature by a gas cutting torch nozzle 2, a part of molten metal adheres to the lower end of the cutting slit 3 as primary slag 72. To remove this slag, a pair of nozzles 5 are provided at the outside of the lower end of the cutting slit 3, and oxygen is blown to the primary slag 72. The primary slag is melted and pushed back into the cutting slit 3, and removed while blowing off by cutting gas flow 8 from the nozzle 2 of cutting torch. At this time, the secondary slag 102 generated by blowing of oxygen from the nozzle 5 is blown off by high pressure current 12 of air, etc. from a succeeding nozzle 11 that follows the nozzle 2 of cutting torch. Thus, gas cutting free from adherence of the primary slag and secondary slag can be performed.</p> |
