ArcelorMittal mainly uses pots with inductors for galvanising flat steel products. We have been testing Atherm’s standard immersion heater (IH) technology in our conditions since 2021.
After completing successful laboratory trials with 24-kW IH, we moved on to industrial pots, and added 50-kW IH. We performed tests on five different hot-dip galvanization lines, and in several Al and Zn alloys baths.
We are happy with the overall results, which confirmed that IH could both add heating power and reduce energy consumption. As emergency heating, IH increased pot heating capacity by ~8% in the Aluminizing configuration tested. The quality of the coils produced during our tests was unchanged.
IHs are simple to implement and to use, as well as being truly flexible. In two years of operation, we have not had any failures.
The primary goal of our tests has been achieved. Indeed, IH provided greater heating power, for example avoiding the need to design new crucibles for sites developing novel products requiring a higher pot-heating capacity. Adding a few IH to the bath limits the cost of such adaptations.
The IH were also successfully used to pursue scheduled production in case of problems with some inductors on specific lines.
Finally, their flexibility allowed us to use the IHs for special operations – for example to prepare a new bath – and to provide more flexibility during maintenance operations.
Matthieu Didier
Senior scientist for Global Research and Development at Maizières-lès-Metz (France)