Tata Steel plant knocks £10k off its energy bill

Stocksbridge, UK – Tata Steel has reduced energy bills on the finishing process at its steel plant in Stocksbridge, south Yorkshire, which supplies industries including aerospace and oil & gas.

The finishing process, called the scarfer, uses a propane burner to remove impurities from lengths of steel ingots/blooms up to six metres long and weighing up to five tonnes. The impurities, in the form of waste gases, are then removed by an exhaust fan, run by a 132 kW motor.

This was wasting a lot of energy and was identified by Patrick Frain, Tata’s electrical section engineer for the billet mill, as a prime candidate for a variable-speed drive. “Halcyon Drives – an ABB Drives Alliance member – was recommended to us,” says Frain.

Halcyon Drives proposed a 132kW ABB industrial drive. This is set to run at two speeds, 30% on standby duty and 100% during scarfing. Running at 30% means there is minimum delay when the motor is ramped up to full speed to extract the gases from the scarfer.

Tata needed the drive panel to be housed outside near the scarfer, as the distance to the existing plant room would mean a prohibitively long cable run. To protect the drive from the weather, Halcyon constructed a panel to IP55, incorporating internal thermostatically controlled heaters to prevent condensation.

The panel features a side mounted air-to-air heat exchanger, for dispersing heat generated from the inverter and protection from high summertime ambient temperatures.

Originally, the fan was run constantly at full speed, with its output constricted by a damper. This was controlled by a PLC that signalled the damper to open when more air flow was needed, when scarfing was in progress.

Following the installation, Tata Steel cut energy use on the process by 165,000kWh – reducing energy costs by around £9,700 per annum and CO2 emissions by 82,500kg. Payback on the project was estimated at less than one year.