Vacuum Degasser (VD/VTD/VOD)
The increasing demand for high quality steel makes the vacuum treatment an essential step in secondary metallurgy process. Tenova Vacuum Degasser units (VD) feature effective removal of hydrogen, oxygen and/or carbon, based on proven technology and experience.
Overview
Vacuum Degasser (VD) allows to degas and decarburize the melt and provides the best conditions for desulphurization and inclusions removal. During the VD treatment, the liquid steel ladle is placed in a vacuum tank that can be of stationary or movable design according to the specific layout needs. Vacuum condition is achieved with a vacuum pump system, formed by mechanical pumps or steam ejectors. In order to promote stirring, inert gas is injected through porous plugs. VD can be equipped with an additional oxygen lance (VD-OB process) and further benefits, such as forced decarburization or chemical heating, can be obtained. Tenova's VD can be designed as a twin unit, in order to maximize productivity without sacrificing process quality, using a single vacuum pump system.
The VOD unit is mainly used for the production of stainless steel, it provides the most suitable condition for extensive decarburization and achievement of high-purity and cleanness. The unit is basically a tank degasser equipped with an oxygen lance, but specifically configured to withstand the heat load from an intense CO emission
It is normally used for deep decarburization of high alloy steel grades, usually to remove carbon without affecting chromium content in the production of stainless steel grades. The VOD unit can be operated as the sole decarburization unit after the furnace (DUPLEX process) or as a refining stage after rough decarburization with an AOD unit (TRIPLEX process).
All the units can be equipped with either mechanical pumps or steam ejectors.
Technical data
VD:
- Hydrogen and Nitrogen removal
- Natural and forced decarburization
- Improved conditions for desulfurization with proper slag management
- Improved conditions for inclusion flotation
- Adjustment of temperature and composition
VOD:
- Extensive decarburization with low chromium losses
- Use of less expensive high-carbon alloys
- High rate of chromium recovery with proper additions
- Chemical heating of liquid steel Hydrogen and nitrogen removal
- Improved conditions for desulfurization with proper additions Improved conditions for inclusion flotation
Innovation
Low operation & maintenance cost
Own vacuum pump design
Own top lance technology
Own level 2 process automation system
Safety & Automation
Safety
Highest safety standards and continuous condition monitoring of the equipment and process
Automation
Depending on the various steel grade and quality demands as well as pre- and post-process cycle times, Tenova automation systems handle all types of process variants and operational procedures for ladle treatment facilities and furnaces, as well as vacuum degassing plants (RH, VD, VOD).
Beside the elementary functionalities, such as basic automation (Level 1 and 2), heat tracking and operator guidance, our process models feature dynamic online optimization for consistent and flexible production.
Environment
Latest Gas cleaning solutions, minimized media consumptions, compact design
Process and environment consulting
Digital
Tenova is pushing the digital transformation and Industry 4.0 and develops innovative solutions that boost your business. Benefiting from state-of-the-art development methods, our software solutions for predictive plant condition, product quality, production planning and energy management contribute in saving operational cost and increasing profitability.
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