Metix has developed air cooled stack dampers for the non-ferrous industry to mitigate the risk of water leaks in to the furnace. The SO2 containing off-gas typical of non-ferrous processes increases the likelihood of sulphidation on water cooled components. Air cooling allows the damper surfaces to run above the dew-point temperatures, whilst still ensuring the structural integrity of the mechanical components. Air flow is balanced during the design phase, using computational fluid dynamics simulations to ensure even cooling air distribution. Cooling air is provided by two stack-mounted fans, each sized to deliver sufficient cooling air. Using a electric rotary actuator, the blade can be rotated through a full 360° to alternate the leading edge and control accretion build up.