| 摘要 |
PROBLEM TO BE SOLVED: To provide a plasma torch for heating molten steel which prevents a melting loss brought about by the heat developed at a torch electrode of the plasma torch for heating molten steel and wear owing to splash, so that it can develop a long life of the plasma torch and improve the casting operation and the quality of a piece of a cast. SOLUTION: In the plasma torch 10 provided with an outer tube 12 where the bottom is closed and cooling water flows inside, and with a tube-type torch electrode 16 that holds a space where argon gas goes through inside the outer tube 12, has a covered bottom, is provided inside with a cooling water supply route 20, and moreover, makes its low end part constitute a discharge electrode part 15, a distance L and an average diameter D satisfy a following equation, in a case that an average diameter over distance L from the bottom surface 15b, where the discharge electrode 15 contacts with cooling water flowing inside, to the tip 15a, is D. 0.5-11=L/D. |
