Blade damper with extensions to reduce boundary leakage

摘要

A blade damper for use in fluid flow control devices having damper blades mounted on an axle and having extension ears mounted at opposite ends of the damper blades. The extension ears are mounted in a 90 degree relationship to the damper blades and are semi-circular at their boundary to allow for rotation with the damper blades. The extension ears prevent fluid leakage through boundary planes perpendicular to the axle when the damper is open thereby providing near linear side blade opening versus fluid flow characteristics.