METHOD AND APPARATUS FOR CONTROLLING COATING WEIGHT IN CONTINUOUS GALVANIZING PROCESS

摘要

A method and an apparatus for controlling coating weight in a continuous plating process are provided to effectively control a coating deviation between left and right sides of a steel sheet, a coating amount deviation between front and rear faces of the steel sheets, and a coating amount deviation with a target coating amount that can be generated by various disturbances based on a simplified coating amount predicting model. In a method for controlling coating weight in a continuous plating process, in which the coating weight of the steel sheet is controlled by adjusting an ejection pressure of air ejected from air knife nozzles on front and rear faces of a steel sheet and a gap between the air knife nozzles on the front and rear faces in accordance with a preset pressure value and a preset gap value, the method comprises the steps of: checking whether a target coating amount is changed or not; calculating a deviation between a previous target coating amount and a present target coating amount when the target coating amount is changed; changing the set gap value in accordance with the target coating amount if the calculated deviation of the target coating amount is smaller than a first reference value; and simultaneously changing the set pressure value and the set gap value in accordance with the target coating amount if the calculated deviation of the target coating amount is not smaller than the first reference value.