A Rotary Air Lock is a mechanical device used to regulate the flow of materials between different pressure zones while maintaining a sealed airlock. It has a rotating drum or vaned rotor that allows materials to pass through while preventing air leakage between system components.

Rotary Air Locks are commonly installed in the ducting after the fan. They manage the movement of particulate pollutants, such as ash or dust, from the fan to system components like cyclone separators and bag filters. Rotary Air Locks improve overall system efficiency and reliability by maintaining constant pressure and avoiding air leakage.