| 摘要 |
PURPOSE:To permit uniform contact of a mold and the solidified shell in the mold and to prevent cracking and deformation by measuring the temp. of a mold wall and controlling water volume in such a manner that the temp. is kept within a specified range. CONSTITUTION:The control unit for spray water is bisected in a longitudinal direction and is provided with respectively independent water flow rate control valves 5, 6 in the respective units. The control of the water volume is executed with lower spray pipes 4 of a 2nd zone in the lower stage. On the other hand, the 1st zone of the upper stage is the liquid contact zone of the mold 1 and a molten steel 11. Since the change in the quantity of heat transmission is small in this zone, the upper spray pipes 3 are preset at the optimum rate determined by the kind of the steel and casting speed to spray the cooling water at the specified flow rate. The mold temp. is measured by thermocouples 9, 10 embedded in the mold in the position near the meniscus and at the prescribed distance from the meniscus. The measured values are inputted to an arithmetic unit 7 to control the flow rate control valve 6. The breakout by which the shell is broken right under the mold is thereby prevented and the casting speed is increased. |
