Swift revamp of 6-strand billet caster increases productivity
Italian steel producer Feralpi Siderurgica (part of Feralpi Group) has granted the final acceptance certificate (FAC) to Primetals Technologies for a revamp of its 6-strand billet caster at the steel plant in Lonato del Garda, Italy. The revamped caster was implemented within just six weeks during the planned summer shutdown of 2023. The project took only 12 months from contract signing to the first cast – usually, similar projects take at least 1.5 years until completion.
The extraordinarily swift implementation was achieved through tailored design features specific to Feralpi’s needs, along with close collaboration and knowledge sharing between Feralpi’s and Primetals Technologies’ technicians. Primetals Technologies engineered the caster bow as a single piece for all six strands and preassembled the equipment before transportation to Feralpi’s location. Moreover, the molds and retractable oscillators were designed and built as a single unit, contributing to a smooth on-site implementation.
Mold Changes During Casting Sequences
Primetals Technologies installed retractable oscillators as part of the revamp, resulting in increased productivity. For conventional billet caster designs, changing a mold requires a complete production stop on all strands. However, the retractable oscillators are mounted on mobile carriages, allowing each oscillator to be detached individually for mold changes. This configuration allows operators to exchange molds on one strand while keeping the other strands operational.
Improved Center Quality of Billets
Primetals Technologies’ scope of supply included key mechanical equipment such as the caster bow, retractable oscillators, strand guiding units, drive adoption of the withdrawal strand unit (WSU), and a pinch roll. The comprehensive electrics and automation solution for the mold/oscillator, including the LevCon Autostart function, and implementation services, rounds off the scope.
Increased Mold Level Stability
As part of the project, Primetals Technologies’ automation experts collaborated with Feralpi engineers to identify optimization areas that could enhance production performance. The evaluation revealed that response times for the withdrawal drives could be improved. The team implemented a new set of LevCon parameters based on a numerical optimization approach.
The new state-of-the-art LevCon function for open stream casting enables improved mold level control, resulting in an average 34 percent improvement for the standard deviation of the mold level, i.e. the value indicating mold level stability. Feralpi has expressed satisfaction with the project, noting that the new technology has set a new standard for precise mold-level control. LevCon’s Autostart function has also become part of Feralpi’s ongoing operations, minimizing the risk of breakouts.
