Abstract: A damper for controlling fluid flow may include a main body, a stator that includes a plurality of stator blades, and a rotor moveably connected to the stator and including a plurality of rotor blades. The damper may also include a rotation mechanism mounted to the main body to move the rotor between an opened position and a closed position. The shape of each of the plurality of stator blades and rotor blades may combine to form a shape such that the velocity of the fluid is increased thereby reducing or eliminating back pressure when the rotor is in the opened position.

Abstract: A damper for controlling fluid flow includes a main body, a stator and a rotor. The stator may be carried by the main body and include at least one blade having a predetermined shape. The rotor may be moveably connected to the stator and carried by the main body. The rotor may include at least one blade having a predetermined shape and may be moveable between an opened position and a closed position. The predetermined shape of the at least one stator blade and the at least one rotor blade may form a converging-diverging nozzle, and the stator and the rotor may be carried by the main body so that fluid flows through the main body substantially perpendicular thereto. The opened position may be defined as the at least one stator blade being aligned with the at least one rotor blade, and the closed position may be defined as the at least one stator blade being offset from the at least one rotor blade.

Abstract: A damper for controlling fluid flow includes a main body, a stator and a rotor. The stator may be carried by the main body and include at least one blade having a predetermined shape. The rotor may be moveably connected to the stator and carried by the main body. The rotor may include at least one blade having a predetermined shape and may be moveable between an opened position and a closed position. The predetermined shape of the at least one stator blade and the at least one rotor blade may form a converging-diverging nozzle, and the stator and the rotor may be carried by the main body so that fluid flows through the main body substantially perpendicular thereto. The opened position may be defined as the at least one stator blade being aligned with the at least one rotor blade, and the closed position may be defined as the at least one stator blade being offset from the at least one rotor blade.