PURPOSE: To permit the cooling corresponding to the change of a strip width by operating the spacing of a slit of a slit nozzle to adjust the width of a cooling water film.
CONSTITUTION: The cross relations among the spacing of the slit 4A, the flow rate of the cooling water and the contraction are preliminarily stored in an arithmetic unit 22 and the necessary width of the cooling water film and the contraction corresponding to the strip width are determined. Next, the spacing of the slit 4A of the slit nozzle 2A to adjust the width of the cooling water film is determined. A moving member 18 is moved by actuating a driving control unit 24 and a driving device 20 to adjust the spacing of the slit 4A. On the other hand, the result obtd. by calculating the total flow rate of the cooling water by the arithmetic unit 22 is inputted to a flow rate control unit 28 which in turn operates a cooling water flow rate regulating valve 26 to inject the cooling water at the prescribed flow rate to a strip 21. The cooling corresponding to the strip width is thereby permitted and the excessive consumption of the cooling water is prevented.
NAKAHARA HISANAO
SATO KUNIAKI
ARAI MAKOTO
