Green credentials complete for cement works

Two final variable speed drives are being fitted in a cement works in Derbyshire to complete its energy efficiency programme. All major axes within the plant are now speed-controlled, reducing total power consumption by 15 per cent or more.

Lafarge Cement UK’s cement works in the Hope valley, the centre of the Peak District National Park, is fitting Mitsubishi 132kW drives to two fans used for cooling the clinker as it exits the kiln. Previously they were damper controlled, which is to say they ran constantly at top speed, with the air-flow controlled by partially closing the dampers or baffles.

The Mitsubishi drives mean that the motors can now have their speeds turned down to provide the exact air-flow required. Energy savings are expected to be significant because the air-flow is proportional to the cube root of the motors’ energy consumption. For instance 50 per cent flow requires one-eighth or 12.5 per cent power!