| 摘要 |
PURPOSE: To produce a good double-layer plated band-shaped metal by detecting the surface condition of plating on the downstream side of a spraying device and controlling a spraying rate for plating and the temp. of the band-shaped metal by this detection signal. CONSTITUTION: The band-shaped metal 1 is made to travel from below to above and is passed successively in plural plating chambers 3 where the hot dip coating metal is sprayed in the form of particulates 5 from respective spray nozzles 4 and the band-shaped metal is plated by lamination of different metals thereon. At this time, the respective spraying stages are previously provided with band- shaped metal heating (cooling) devices 6 before and behind these stages and the downstream side of the respective spraying stages is provided with plating state detectors 7. The plating states in the respective stages are detected by these detectors 7. The optimum spraying rate of the plating metal and the temp. of the band-shaped metal are determined by an arithmetic processor 11 in accordance with the detection signals 12. The spraying rate from the nozzles 4 and the temp. of the band-shaped metal are controlled by control signals 13, 14. As a result, the good double-layer plated steel sheet is obtd. |
