Siemens VAI Metals Technologies has received an order from the Steel Authority of India (SAIL) to supply an RH vacuum degassing plant to the Rourkela Steel Works in the state of Orissa.
The new plant will allow high-quality steel grades up to cold-rolled non-oriented types to be produced. The order is worth a total of some ten million euros. The RH plant is scheduled to come into operation by the middle of 2012.
Liquid steel after treatment in a Siemens RH degassing plant.
The main functions of the RH degassing plant in the Rourkela Steel Works are the removal of hydrogen, forced decarburization and the chemical heating of the liquid steel. The liquid steel is treated under vacuum conditions with argon as lift gas for circulation of steel. Twenty-four heats can be treated per day, which amounts to a production capacity of about one million tons of liquid steel per annum.
The Siemens RH plant has a capacity of 150 tons, and is designed as a Mono-block design vessel with welded snorkel tubes. The RH-vessel is raised and lowered by a winch system. The scope of supply includes a five-stage vacuum pump, an alloying system, a T-COB (Combined Oxygen Blowing) lance for producing low-carbon types of steel grades, and complete level II process automation. The pressure conditions in the RH vessel are continuously adjustable, which enables the vacuum conditions to be adjusted precisely to the particular requirements of each steel grade, and also reduces the energy requirement. Pre-evacuation shortly before the vacuum treatment accelerates the evacuation of the vessel so the actual metallurgical process can start more quickly. Siemens is also responsible for the design, configuration and construction, as well as for supervising the installation of the RH plant and the associated auxiliary installations.
Rourkela Steel Plant was the first integrated steel plant in the public sector in India and also the first in Asia to adopt the LD technology. This order is unique in the sense that it has re-started the relationship between Siemens VAI and RSP in bringing about further enhancement of technology for production of special grades of steel. The new RH plant is part of SAIL's modernization and expansion program for its Rourkela location, which is intended to increase raw steel production to around 4.2 million tons per year. A third BOF converter will be constructed in steel works II with secondary steelmaking facilities – including the Siemens RH plant, and a continuous slab caster.