Drives replace dampers to achieve immediate energy savings

摘要

Two modular ac drives from Control Techniques have not only produced immediate energy-savings on a previously mechanically damped fan application, but also rnpaid for themselves in under a year.rnCivil and Marine's Middlesbrough plant imports blast furnace slag from the nearby Corus steelworks and grinds it into a fine powder to produce ground granulated blast-furnace slag (GGBS), a very useful by-product that is used to enhance the properties of concrete, replacing between 20 and 80% of the cement content. Concrete containing GGBS is less permeable and chemically more stable than conventional concrete, and offers superior resistance to sulphate attack and cracking caused by alkali-silica reaction.rnHowever, GGBS is a highly abrasive material and excessive wear and tear on dampers prompted engineers at the site to find an alternative means of controlling the airflow that extracts the product from the ball mill and Sepol separator. Site electrical engineer and assistant works manager, Rob Thwaites takes up the story.