Siemens Metals Technologies, Austria, has completed a vacuum oxygen decarburization (VOD) plant with a capacity of 50 metric tons at Voestalpine Giesserei Linz GmbH. The Austrian company is thereby adding to its equipment for secondary metallurgical treatment of steel castings for sophisticated applications in the energy and mechanical engineering industries. The plant features electrically driven mechanical vacuum pumps instead of steam injectors and therefore does not require a steam generator.
Siemens handled the configuration and supplied all the core components. These included, for example, a special ladle hood made of copper-plated sheet. This minimizes the occurrence of baked slag on the upper edge of the ladle and on the vacuum lid. The scope of supply also included the vacuum lid, an oxygen-blowing lance system, a gas cooler and a filter system, mechanical vacuum pumps and the hydraulic system. The order also included a water management system matched to the overall plant as well as the complete automation technology and instrumentation.
As one of the first VOD systems worldwide, the plant in Linz uses a combination of electrically driven, mechanical vacuum pumps to generate a vacuum. This includes roots blowers and screw compressors. Unlike the conventional steam injectors used in secondary metallurgy, these do not require any process steam, so there is no need for any external steam or the installation of a separate boiler to generate steam.
