PURPOSE: To wash away the refrigerant sticking on a steel wire rod to a permissible value or below in the stage of washing away the refrigerant sticking to the steel wire rod by determining preliminarily the lowest flow rate of the washing water meeting an operating condition and controlling the flow rate to the lower limit value or above.
CONSTITUTION: The detection signal of a refrigerant concn. detector 14 disposed in a washing tank 4 is inputted to a concn. controller 13 in the stage of washing the refrigerant sticking to a steel wire rod. The controller 13 feeds the output therefrom to a lower limit operator 16 so that the output signal from the detector 14 meeting the balance value corresponding to the permissible value of the final amt. of the refrigerant sticking to the wire rod is obtd. A lower limit operator 16 controls a signal 15 for the set value of the flow rate of the washing water so as not to fall below the lower limit value of the flow rate of the washing water determined by the operating condition. A controller 10 for the flow rate of the washing water controls a control valve 12 by receiving the set signal 15 and the signal from a flow rate detector 11 interposed in the washing water flow passage. As a result, the flow rate is controlled while the limit value of the flow rate of the washing water is maintained under said operating condition by the operator 16.
ABE MITSUHIRO
HANASAKI MIKI
SADANO YUTAKA
ITOU KATSUTO
NIPPON STEEL CORP