Steel Degassing Steel degassing processes require robust and reliable vacuum systems. Our vacuum equipment lets you build a sustainable steel degassing plant.

Vacuum solutions for steel degassing processes

A steel degassing plant is a facility used in the production of high-quality steels. It is designed to remove elements such as carbon, hydrogen, oxygen, and nitrogen from the molten steel by a process known as vacuum degassing

During vacuum degassing the liquid steel is treated under vacuum which is created with a vacuum pump system.

The steel degassing process can have very specific requirements depending on the facility design, metallurgy routes, and desired quality of the final product.

Types of steel degassing processes can be split into three main groups:

VD – Vacuum Degassing
VOD – Vacuum Oxygen Decarburization
RH - Ruhrstahl-Heraeus process

VD – Vacuum Degassing

Vacuum treatment of molten steel where a vacuum is applied in a special chamber - degasser with a ladle of molten steel inside. The typically targeted operation pressures range from 1.33 mbar (1 Torr) to 0,67 mbar (0.5 Torr)

VOD – Vacuum Oxygen Decarburization

Vacuum process where pure oxygen is blown onto the surface of the molten steel in a pressure range of 50-200 mbar. The carbon content of the steel is oxidized, converted towards a gaseous CO/CO₂mixture which is then evacuated via the vacuum system. Typically, after the rough vacuum VOD process step, a VD process at low pressure follows, combining these two steps inside the same degasser design

RH - Ruhrstahl-Heraeus process

High productivity steel degassing process. The steel circulates inside a degassing chamberwhich is immersed into the steel ladle. Vacuum is used to lift up the steel into the degassing chamber and ensures the degassing itself (as in VD). The high circulation speed of the molten steel is ensured by an Argon flow into one of the suction snorkels. A RH-degasser can also be used for carbon reduction by blowing pure oxygen onto the circulating melt during a rough vacuum step, this is then called a RH(O) process.

VD – Vacuum Degassing

VOD – Vacuum Oxygen Decarburization

RH - Ruhrstahl-Heraeus process

The vacuum system is a critical component for the steel degassing process as it enables the creation and maintenance of the required vacuum level in the chamber. There are two rivalling types of vacuum solutions in steel degassing plants. Historically steam ejector vacuum systems (often with liquid ring vacuum pumps) are used while today mechanical vacuum systems consisting out of combinations or Roots blowers supported by dry screw vacuum pumps became a cost-saving and environmental friendly alternative.

Leybold offers an optimal portfolio of components for a modern and efficient steel degassing facility:

Forevacuum pumps – Dry Screw Pump DRYVAC DV 1200 – DV 1600
State-of-the-art dry screw vacuum pump with unprecedented robustness and highest level of reliability. DRYVAC vacuum pumps are the proven solution for many very harsh applications, and therefore perfectly suitable for the demands of steel degassing applications
Forevacuum pumps – RUVAC WH 7000
High-performance booster - fully hermetically sealed, without wearing shaft-seals, FC driven. The Roots blowers ensure the required pumping speed in combination with the DRYVAC fore-vacuum pumps.
Vacuum pump station concept – Vacuum skids
Leybold combines the individual pumps into modular systems with a scalable concept. The modular design of the system gives full flexibility for the best configuration of the individual degasser requirement: Typically 3 stage or 4 stage skids are chosen and depending on the required pumping speed several skids are installed in parallel.
Power and control system
Our intelligent control system allows to precisely tune the operation of all pumps by their frequency drives. The system gives the possibility for the master PLC to control all pumps inside one system as one virtual pump. The system provides several operation modes for the degasser to obtain the required pumping speed and to avoid slag foaming, always ensuring safe operation of all components even for continuous operation.
Gas cooler
Depending on the temperature of gases coming from the degasser during VD/ VOD or RH processes, the gases need to be cooled down to avoid overheating of dust-filters or vacuum pumps. Temperature sensors...