Simply upgrading fans inside a grinding mill at a UK cement factory was enough to save the company more than $269,000 per year.
The Purfleet Works of Hanson Cement is located on the River Thames in Essex, England, and has the capacity to produce about a million tons per year of Regen, a special type of cement that is made of ground-up blast furnace slag.
The slag is ground within two closed circuit ball mills equipped with vertical grinding mills. In one of the mills, Hanson Cement replaced a fixed-speed fan with a more energy efficient fan produced by the German equipment manufacturer Siemens. Not only does the new fan require substantially less power, but it also has reduced the plant’s CO2 emissions by 1,600 tons per year, according to Dave Jackson, the plant’s electrical engineer.
“We were looking to make energy savings around the plant and a survey had recommended a new drive and motor for this mill,” Jackson said. “The Siemens solution means we are now running with the damper open 100 percent of the time, yet actual energy consumption has dropped by around 360 to 400 kilowatts.”
The fixed speed fan was replaced with a Siemens 1,000 kW Sinamics Perfect Harmony 11,000/4,160 V medium voltage converter, installed and commissioned to link with existing Siemens process control systems at the plant.
The concrete replacement made at the plant is ready-mixed and pre-cast concrete.