Siemens Metals Technologies GmbH (Willstätt-Legelshurst, Germany):

Pezza A., Product Lifecycle Manager VD/VOD, andrea.pezza@siemens.com

Abel M., Senior Expert Electric Steelmaking
Hein M., Head of Process and Metallurgy
Wieting T., Senior Sales Manager Steelmaking & Secondary Metallurgy

Vacuum plants are increasingly being installed in so-called mini mills in addition to integrated steelworks and stainless steel production. This article deals with the design and results achieved with the recently commissioned VD plant at SSAB in the USA, the VOD plant at Tisco in China and the RH plants at CSA in Brazil and Zhangjiagang in China. 185-t VD vacuum pump performance is examined as well as filter unit characteristics of the 185-t VTD. The results of hydrogen removal at ladle refining furnace and nitrogen removal in a tundish of continuous casting machine during the first test phase are analyzed depending on number of heats. Copper-clad ladle roof and 3-D model for Tisco’s 180-t VOD are presented. Decarburization rate, content of residual elements and pump performance data of two 180-t RH-OB in Shagang are shown with investigation of VP full steam, pressure and suction capacity. As well, decarburization results, main performance test results (including treatment cycles, chemical heating, skull removal and temperature accuracy) and vacuum pump performance data are displayed for the 220-t RH-OB of ThyssenKrupp CSA in comparison with contractual data. A perspective is provided on secondary metallurgical vacuum processing in the light of current trends in the market.