NLMK boosts French coil galvanizing line productivity

NLMK France is investing in process management at its 400,000 tonnes/year coil galvanizing line in Strasbourg, to boost productivity and prevent human error.

The producer has installed a predictive furnace control solution designed by French equipment maker Fives called “VirtuoTM”. The digital system has been customised according to the furnace features and the need to boost quality as well as limit losses, Fives says.

While modern lines are equipped with gradual temperature rise features, the line in Strasbourg featured a furnace that generated rapid temperature increases over short distances. A better temperature variation control avoids rejects as well as financial losses.

“Conventional control methods proved inadequate due to latencies, downtime, and non-linear process effects … The deployment of VirtuoTM-L began with simple modelling based on physical equations and complex parameters to adjust to the atypical furnace. Later, it transformed into a hybrid model, combining recorded data with automatic coefficient calculations,” Fives tells Kallanish.

“This transformation allowed the furnace to compensate for physical phenomena not captured by the initial model,” it adds.

The adapted solution is now capable of reading the furnace’s response to temperature variations. Thanks to a gloss metre at the furnace’s entrance measuring strip brightness, it allows furnace readjustments to resolve quality issues related to the surface condition of incoming coils.

The customised system has resulted in continuous improvement of product quality, reduction of downgraded coils, and simplification of the operators’ work, NLMK says in a joint statement.

Natalia Capra France