METHOD FOR PREVENTING NEGATIVE PRESSURE IN PRESSURIZING CHAMBER OR COOLING CHAMBER OF CONTINUOUS VACUUM DEPOSITION PLATING LINE

摘要

PURPOSE:To prevent the negative pressure of a pressurizing chamber or cooling chamber without generating hunting by supplying gaseous nitrogen to a sealing roll chamber or cooling chamber which is a post stage of the pressurizing chamber. CONSTITUTION:A steel sheet 7 is conducted via the pressurizing chamber 1 and sealing roll chamber 3 to a vacuum deposited chamber. The gaseous nitrogen is filled in the pressurizing chamber 1 through a supply path 8. The gaseous nitrogen leaks between the pressurizing chamber 1 and the outside of sealing rolls 4 on passing of the weld zone of the steel sheet 7. A pressure fluctuation is detected by a differential pressure transmitter 10 when a differential pressure arises. A control valve 12 of the gaseous nitrogen supply path 8 is automatically released through the control valve 11 and the prescribed amt. of the gaseous nitrogen is replenished into the pressurizing chamber 1. A control valve 15 of the supply path 9 is opened at the same instant and the prescribed amt. of the gaseous nitrogen is supplied into the chamber 3. The generation of the negative pressure in the pressurizing chamber 1 is thus prevented.