PURPOSE: To perform an effective preliminary treatment of hot metal by inserting a vertical tube while preventing a pretreatment slag from intruding into the tube by keeping hot metal within a vessel capable of freely being sealed, and by injecting the preliminary treatment agent of hot metal into the hot metal within the tube while pressurizing the inside of vessel.
CONSTITUTION: The bottom end of immersion tube 4 is dipped into hot metal 3 by pouning out the hot metal 3 into the vessel 2, which is sealed by attaching a cover thereto. The surface of hot metal 3 in the immersion tube 4 is caused to rise by pressurizing the vessel 2, and a lance (6) for injecting the treatment agent is inserted into the immersion tube 4 when the bath surface reaches a fixed height. Thereafter, the preliminary tretment agent of hot metal is injected into the hot metal 3.
NOZAKI TSUTOMU
TAKEUCHI HIDEJI
HARA YOSHIAKI
