| 摘要 |
<p>PURPOSE:To attain cooling stop temperature control with high accuracy and with a simple equipment constitution by dividing a cooling zone into plural groups and changing the number of nozzles in a group in proportion to an acceleration rate or a deceleration rate without changing a water injecting nozzle flow and a cooling zone length. CONSTITUTION:A group 10 obtained when a multitude of cooling nozzles is divided into groups is composed of combinations of four control valves 11,12,13,14 having two nozzles each. Therefore, the cooling temperature of a steel sheet 1 can be changed by varying the number of nozzles of the cooling zone in proportion to variation in rolling speed of the steel sheet 1 without varying the length of the cooling zone to vary the thermal flux. Consequently, the cooling capacity of the steel sheet 1 is changed continuously corresponding to the variation of the speed without controlling a control unit by an interval between arranged headers like the cooling zone length changing method and the target cooling stop temperature can be obtained accurately without causing an error in the accuracy of the cooling stop temperature.</p> |
