Mill fan upgrade cuts energy use

A fan upgrade at the Purfleet Regen works in Essex has resulted in a 50 per cent reduction in energy on one of the grinding mills, reducing CO₂ emissions by 1,487 tonnes per year.

The works uses two closed circuit ball mills and a vertical grinding mill to make Regen. Electrical engineer Dave Jackson said: “We were looking to make energy savings around the plant and a survey recommended a new drive and motor for one of the mill fans. It was running at a fixed-speed at 900 kilowatts with the airflow controlled by a damper. The new Siemens equipment allows us to run with the damper open all the time, yet energy consumption has dropped to around 430 kilowatts.

“It took about a month before we could clearly identify all the changes in running costs, but we were very pleased with the whole system, and the savings were greater than we originally anticipated.“

Other benefits of the upgrade include greater productivity through optimised speed and process performance, and reduced maintenance.