Coating weight control on ArcelorMittal’s galvanizing line at Florange Works

ArcelorMittal’s hot dip galvanizing line at Florange has developed and commissioned its own coating weight control system. This system automatically controls air-knife pressure and position to give a constant and uniform zinc coating in accordance with customer-order specifications through a model-based feedforward controller and two feedback controllers. Moreover, continuous adaptation of the knife-to-strip distance allows a fast and accurate response to process fluctuations under the entire range of operating conditions. Due to speedy acceptance of this system by line operators, large and rapid benefits, i.e. quality improvement and zinc savings, have been achieved immediately after it was put into production.