Vacuum Decarburization Ordered for Austrian Foundry

Aug. 1, 2012
Siemens supplying system that uses electrically driven mechanical vacuum pumps; no need for a steam source

Voestalpine Giesserei Linz GmbH, an Austrian steel and iron foundry, has ordered a 50-metric ton vacuum degasser from Siemens VAI Metals Technologies. The new equipment will handle secondary metallurgical treatment of specialty steel alloys, particularly steel grades required for the cast products supplied to power-generation system developers and heavy equipment builder.

The value of the contract was not announced. The new vacuum decarburization plant should be in operation by the end of this year, Siemens indicated. The installation will expand the Linz plant’s current secondary metallurgical processing options, allowing it to expand its product portfolio, and it “will make a significant contribution toward cost-efficient production,” the contractor announced.

Siemens VAI Metals designs steel plant equipment, from blast furnaces to oxygen furnaces, to continuous casting machines. The former Voest-Alpine Industrieanlagenbau was taken over by Siemens AG in 2005.

Voestalpine Giesserei Linz GmbH is a subsidiary of Voestalpine Stahl Linz GmbH, an integrated steelmaker, and has two production units in Austria for ferrous (in Linz) and nonferrous (in Traisen) castings. The ferrous foundry casts engineered components (10 to 200 metric tons) for specialty manufacturing equipment, including hammer heads and housings for forging machinery; rolling mill housings; slag ladles; castings for steam turbines, gas turbines, and gas pipeline compressors; and other products for petrochemical and oilfield installations.

The foundry also has plants in Yinchuan and Shanghai, China. It produces approximately 35,000 metric tons/year of steel, ductile iron, and nonferrous castings.

Siemens will engineer the installation and supply the core components for the new vacuum decarburization plant. This will include a special ladle roof in copper-clad sheet steel that will minimize the skull formation at the top of the vessel and the roof. The scope of delivery also includes the vacuum roof, an oxygen-blowing lance, a gas cooler, filter system, mechanical vacuum pumps, and the system’s hydraulics. Also included in the order is a water management system tying into the Linz Works infrastructure, and all the process controls, instrumentation, and automation for the vacuum system.

The engineering group explained this will be one of the world’s first VOD systems to create a vacuum using electrically driven mechanical vacuum pumps, including Roots blowers and screw-type compressors. “In contrast to the conventional steam ejector pumps used in secondary metallurgy, these do not require any process steam,” Siemens VAI reported. “There is therefore no need for an external source of steam or for installing a separate boiler to generate steam.”