Provided is a blade stabilization apparatus for a relief damper, and more specifically, to a blade stabilization apparatus for a relief damper which can stably maintain an opening angle of a damper blade at any angle when the damper opens or closes after the center of gravity is always aligned with a centerline of a rotating shaft in a perpendicular direction to the damper blade.

Provided is a blade stabilization apparatus for a relief damper, and more specifically, to a blade stabilization apparatus for a relief damper which can stably maintain an opening angle of a damper blade at any angle when the damper opens or closes after the center of gravity is always aligned with a centerline of a rotating shaft in a perpendicular direction to the damper blade.

A boot loadable air damper includes an actuator, a support base supporting the actuator, and a foldable sheet member attached to the support base for securing the damper device to an inner surface of the ductwork. The air damper device also includes a foldable damper blade that is foldable at first and second tensioned hinges which bias it towards an unfolded state and, when fully unfolded into the unfolded state, at least one stop member acting against the first and second tensioned hinges restricts further unfolding of the foldable damper blade.

Shutter structure includes rotary shaft provided in duct line, shutter plate rotated about the rotary shaft and disposed to switch between open state and a closed state, and upper rib and lower rib provided on an inner wall of duct line. Shutter plate has a peripheral edge portion constituted by an upper shielding plate and two lower shielding plates, a curved portion, and shutter plate shaft portion. The lower shielding plates are located at positions symmetrical to each other with respect to a center line perpendicular to the shutter plate shaft portion, and the upper shielding plate is located on the center line. When shutter plate is in the closed state, the upper shielding plate comes into contact with the upper rib from an upstream side, and the lower shielding plates come into contact with the lower rib from a downstream side.