Patent ID: 7665458
Filing Date: 2010-02-23
Classification: F23C,F23L

Abstract:
1. A damper and overfire air duct assembly in a combustion system having a combustion structure defining a flue gas passage, the damper and overfire air duct assembly comprising: an outer overfire air duct having an inlet and an outlet discharging overfire air into the flue gas passage, wherein the overfire air duct has a longitudinal axis extending through the inlet: an inner overfire air duct enclosed by and concentric to the outer overfire air duct, wherein the inner overfire air duct has an inlet and an outlet discharging overfire air into the flue gas passage, and a damper aligned with the longitudinal axis of the outer overfire air duct, and having an open position in which the damper extends axially outward of the inlet to the inner overfire air duct, and a closed position in which the damper is at least partially in the inlet to the inner overfire air duct, wherein the damper is movable axially along the longitudinal axis between the open and closed positions.