Engineering Steel Belgium (ESB) reports saving €45,000 per annum with three cooling pumps on one of its electrical steel furnaces, since installing WEG W22 132kW, IE2 high efficiency motors, controlled by CFW-09 variable speed drives.
The equipment was supplied by Leclercq Energy, to Process Automation, which supplied and commissioned the package, including control panel with drives, soft starters, PLC and process supervision via a Profibus-DP digital plant communications system.
Seraing, Belgium-based ESB, which produces steel for transport, energy generation and aeronautics industries, has been running an energy reduction programme focusing on its electric UHP (85MVA) arc furnaces.
These are cooled in a closed circuit system, which includes three large pumps driven by 132kW motors. Hence ESB's decision to replace the existing standard motors with three of Weg's new W22 high efficiency machines.
However, since the existing motor control system was controlled using contactors – meaning full speed operation – ESB also went for the drives, following an audit by specialist Process Automation.
That led to the Weg CFW-09 132kW inverter drives selected for the motor control task, equipped for self-tuning, which automatically matches the drive to the motor and load.
Now, normal weekday operation between 3pm and 8pm requires just one pump, running at 70%, while from 8pm to 11am, two pumps are in operation, running at 89.2%.
At weekends and shutdowns, when frost could be a problem, two pumps are still required, operating at 89.2%, but only for five minutes in every 30.
Hence the annual savings of €45,000, or 38.5%.
