| 摘要 |
PROBLEM TO BE SOLVED: To reduce cost of gas needed for gas sealing and gas wiping arranged above the plating bath in hot-dip Mg-containing zinc plating, and to simplify a gas feeding device. SOLUTION: This method is characterized by employing a low-purity nitrogen gas provided by a nitrogen-gas manufacturing method of a PSA(Pressure Swing Absorption) type, which adsorbs and removes oxygen from compressed air, for a sealing gas and a wiping gas. An oxygen content in the wiping gas is preferably 1 ppm or lower, and the oxygen content in the sealing gas is preferably 8 ppm or lower. The low-purity nitrogen gas is supplied from a low-purity nitrogen gas feeder having an air compressor (11), an air tank (12), and an adsorption tower (13) for adsorbing and removing oxygen from compressed air, to a gas wiping device (3) and a seal box (4) of a hot dipping device, through a buffer tank (14).
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