MMK rolls first coil on two-stand Compact Cold Mill modernized by SMS group

The two-stand four-high Compact Cold Mill supplied by SMS has been successfully in operation since 2002. In February 2020, MMK decided to reconstruct and upgrade the mill. After a thorough assessment of the equipment jointly with SMS, MMK had decided to integrate future-proof technological features of the latest state of the art.

The ambitious goal to be ready to produce the first coil in only twelve months has been successfully accomplished. Both on the entry and exit side of the CCM®, a new reversing reel was installed. These reels are equipped with a gear stage and a hollow shaft to enable quick mandrel changes.

While the existing mill housings were reused, key mechanical and actuating equipment was renewed.

The bearings of the back-up rolls were converted to anti-friction design. To this end, the chocks of the back-up rolls and the oil/air lubrication system were completely renewed. In addition, further essential actuating systems were completely renewed: the cylinders of the hydraulic roll adjustment system, the cylinders and the bending block cassettes of the work roll bending system, the CVC®plus (Continuously Variable Crown) work roll shifting system and the wedge adjustment system for the passline control.

For the mechanical drives of the stands, SMS supplied new gearboxes, brakes and drive spindles, complete with new spindle head supports.

In order to make the mill fit for future quality requirements, in particular in terms of strip flatness, additional quality-enhancing systems and components were included, as multi-zone cooling at both stands, two X-Shape flatness measuring rolls and strip tension measuring systems, for example.

All valve stands for the high and low-pressure systems were replaced. Even a new mill stand platform and new piping in the proven AIO (All In One) design were installed.

The emulsion system was equipped with new filter units to assure consistent emulsion quality and excellent cleanness of the strip surface. Specifically, vacuum filters, chain-type magnetic separators and additional backflush filters were installed.

The scope of mechanical supplies was completed by new Dry Strip systems, installed at both rolling stands for the removal of emulsion residues from the strip surface, and roll shop equipment.

“Given the current, global COVID-19 crisis, we were faced not only with technological challenges in this project. My special thanks go to MMK’s and our teams. Thanks to their strong commitment, dedication and pragmatic approach, it has been possible – even under the restrictions due to the pandemic – to complete this project according to schedule with the production of the first coil after only twelve months,” says Marc Hoffmann, Executive Vice President Flat Products of SMS group.