As part of a two-stage modernization project completed at the end of 2008, Siemens VAI Metals Technologies increased the annual production capacity of Italian steel producer Ferriera Valsabbia to 750,000 metric tons of reinforcing steel. The prime reasons for achievement of this approximately 25 per cent increase in output were the installation of a hot-charging system for billets as well as a system for single-bar high-speed delivery that allows rolling speeds of up to 27 meters per second in two-slit rolling mode.
The aim of modernizing the rolling mill of Ferriera Valsabbia, which is located in Odolo in the province of Brescia, was not only to expand production capacity but also to increase the flexibility of the facility. The new rolling mill is designed to process billets with square cross-section of 150 x 150 millimeters and length of 9 meters. This results in rebars with diameters of between 8 and 40 millimeters. In two-slit rolling mode, the maximum bar diameter is 20 millimeters. The re-heating furnace, which has a capacity of 100 metric tons per hour if the billets are cold-charged, can be accelerated to up to 130 metric tons per hour with the help of the hot-charging system supplied by Siemens.
For the rolling line, Siemens supplied 14 new Red-Ring stands and modernized the existing seven stands. The rolling line now allows the rapid replacement of rollers and stands and thus a flexible changeover to different end products. Bar transfer to the new 64 meter-long cooling bed takes place by means of a lifting apron with magnetic brakes or alternatively by means of a high-speed bar delivery system. The latter is designed in such a way that individual steel bars can be transferred to the walking rakes even in two-strand rolling mode. This makes it easier to count and bundle the bars later. Thanks to the high-speed delivery system, rolling speeds of up to 27 meters per second are possible compared to the fifteen meters per second when lifting aprons are used. The scope of supply also included all the shears of the rolling line, the cold cutting area as well as machines for counting and bundling the steel bars. Siemens was also responsible for the lubrication and hydraulic systems and supervised the installation work and commissioning of the rolling mill. Siemens also supplied consulting services in order for Valsabbia to apply for the safety certifications of both individual machines and overall plant, as required by Italian / European regulations.
Siemens VAI had received the order to modernize the rolling mill in 2006. The project was carried out in two phases: during 2007 and during 2008. Existing equipment and spatial restrictions had to be taken into account in the project planning process in order to minimize down times and production outages.