Fans of saving energy
When Hanson Cement’s GGBS factory in Purfleet, UK, was looking to achieve energy savings, it chose to upgrade the fan of Mill 3 with Siemen’s Integrated Drive Systems concept. The new drive and motor has enabled the plant to reduce drive speed and power consumption, thus saving 4.5Wh/t on its overall process with this one fan drive. By Siemens AG, Germany.
Hanson Cement’s factory in Purfleet, UK, produces 1Mta of Regen ground granulated blastfurnace slag. The plant operates two closed-circuit ball mills as well as a vertical grinding mill.
The fan of Mill No 3 used a 1MW, 11kV slip-ring machine operating at around 980kW. The fixed-speed fan was continuously running at 350,000m3/h, with a damper used to bring it down to approximately 241,000m3/h.
At such unnecessarily-high operating volumes, the fan proved very energy inefficient and expensive to run and Hanson Cement therefore decided to implement an upgrade. “We were looking to achieve energy savings around the plant, and a survey had recommended a new drive and motor for this mill,” explains Dave Jackson, Hanson Cement’s electrical engineer.