Plugging device

摘要

Disclosed is a plugging device which comprises a plugging orifice having in a passage for a liquid metal a conical portion spreading out toward the upper-course side and a straight pipe portion extending from a small-diameter part of the conical portion at the lower-course end thereof to the lower-course side, whereby plenty of impurities in the liquid metal flowing supersaturated through the straight pipe portion are precipitated at the straight pipe portion, and a cooler so controlled as to stop a driving motor of a blower for cooling the liquid metal when the flow rate of the liquid metal is below a predetermined level and to rotate the motor in proportion to the deviation between the flow rate by actual measurement and the predetermined level of flow rate when the flow rate of the liquid metal is at the predetermined level or above.