November 22, 2008
CSN to modernize CR tandem CR mill No 3 at Volta Redonda
Companhia Siderúrgica Nacional has awarded Siemens VAI Metals Technologies a contract to modernize its five stand tandem cold rolling mill No 3 in Volta Redonda. The aim is to further improve product quality and to increase output. The modernized plant will start operating in the second half of 2009.
The project also includes replacement of the automation system, renewal of the drive and process equipment as well as modification of the rolling stands, the in feed and out feed areas and the emulsion cooling systems.
Under the project, Siemens will modernize the drive controllers, the entire automation system, the technological control systems and the operator control system. The new equipment, which will be based on the Siroll CM concept for cold rolling mills, will see the plant fitted with a thickness control system in accordance with the advanced mass flow concept and new process models, which enable fully automatic adjustment of the rolling line to the different operating modes. Simplified operator control, integrated diagnostic systems and fully automatic rolling sequences are designed to increase the productivity of the facility.
In addition to all this, Siemens will carry out extensive renovation work on the mechanical equipment. This includes new hydraulic cylinders for all rolling stands, including servo valve stands, modifications of the mounting parts on the work rolls and on the roll changing system to ensure automatic roll change, plus additions in the infeed and outfeed areas. This will enable optimization of strip movement and further improvements in the quality of the strip surface. Comprehensive modernization of the emulsion plant rounds off the project.
The plant will be revamped as part of a scheduled shutdown in the second half of 2009. Pre assembly and pre-commissioning of some of the functions will reduce non-productive time to a minimum. Customer training will be conducted in the context of an expanded system test in situ and customer specific requirements can also be integrated.
The project is being handled with the support of Siemens Brazil. The contract was awarded to Siemens based on the positive impressions left with the customer during the recently completed changeover of the drive systems of tandem line No 2 to digital controllers and thyristor supply units. Siemens also made a positive impression with its ongoing preventive and corrective maintenance work in the Volta Redonda Continuous Casting plants.
