Hydraulic AOD tilt system boosts production at UGITECH France

The UHT team installed and commissioned the hydraulic drive for the AOD converter during the summer maintenance stop at UGITECH, France.

In August this year UHT installed a hydraulic drive for the AOD converter at UGITECH, France. The drive replaces the earlier electromechanical solution with gearbox and electrical drive. UGITECH estimates that with the hydraulic drive an average capacity increase of 4 tonnes per work shift is now possible in their 57 tonne capacity AOD vessel. The capacity increase is based on the fact that there is no longer any need for reduced blowing or tonnage limitations for the first charges in a newly relined vessel. This was previously necessary due to the severe vibrations and shocks during processing with the now replaced electromechanical drive.

Measurements made by UGITECH show vibrations to have been reduced by as much as 1000 times. Better control of the rotation and tilting of the vessel has also been achieved, since the hydraulic motor provides rapid and direct response with full torque from zero speed. These features save further operation time and minimize costly metal losses during deslagging.
In a hydraulic system, the oil serves as a built-in damper to vibrations and shocks. UHT has further improved this by applying an adjustable counter balance valve solution to the drive to handle severe vibrations which typically occur during converter refining. Wear and maintenance is minimal since all moving parts of the hydraulic drive are always in contact and are embedded in oil.

AOD Hydraulic Drive

Jean-Francois Muller, steel plant manager at UGITECH, concludes:
“The UHT hydraulic converter tilting solution enables us to maximize our AOD refining performance while minimizing any downtime and need for maintenance. With the short delivery time, 7 months in total, the hydraulic solution made it possible for UGITECH to schedule the revamp during our 2012 summer maintenance stop.”

The correct hydraulic drive solution is selected and adapted by UHT for each customer application and assembled for delivery. The solution comprises one hydraulic motor fitted on the trunnion ring with shaft and with a torque arm fixed to the foundation. The hydraulic drive enables rotation as well as maintaining the position of the vessel during charging, tapping and deslagging. A disc brake provides an additional possibility for mechanically locking the converter positions, typically during maintenance. Hydraulic pressure is generated in a power pack unit, placed in an adjacent location. The UHT solution is both cost and time efficient. The startup at UGITECH was performed within 7 months from the date of order.

UGITECH in Ugine, France has an annual steel production of 200,000 tonnes and is part of the SCHMOLZ + BICKENBACH group, the world’s largest manufacturer, processor and distributor of special steel long products.
UHT is a Swedish engineering company, prior to 2008 known as UDDEHOLM Technology, active in the area of AOD converter refining of stainless steel and ferroalloys. Complete new converter deliveries are possible as well as revamping and upgrading. Deliveries include gas mixing stations and full automation, both PLC and level 2 where the real-time UTCAS® process control system handles all aspects of modern AOD operations. UHT is the inventor and has the know-how, equipment and process control for the use of superheated steam as an additional process gas, the CLU® process.