Patent ID: 8647182
Filing Date: 2014-02-11
Classification: B08B,F04D,F23L,F24F,Y10T

Abstract:
1. An exhaust fan assembly comprising: a substantially cylindrical outer enclosed wall having an air inlet and an air outlet, the outer enclosed wall including at least one elongated opening extending along the majority of a side between the air inlet and outlet; an inner enclosed wall being positioned within the outer enclosed wall and including at least one elongated opening; an annular space defined between the inner enclosed wall and the outer enclosed wall, wherein an upper end of the inner enclosed wall flares outward toward the outer enclosed wall so as to constrict the annular space to form a nozzle; a windband mounted to the outer enclosed wall, the windband having a tapered body defining an inlet having a circular opening; a roof and a bottom plate secured to the inner enclosed wall, wherein the roof, the bottom plate, and the inner enclosed wall define a bearing chamber; a fan disposed within the outer enclosed wall and upstream of the bearing chamber, the fan being configured to move exhaust air through the air inlet, the annular space and the air outlet, the fan being configured to move ambient air through an inlet of the windband to an outlet of the windband; a rotatably mounted shaft connected to the fan, the shaft extending through the bottom plate and into the bearing chamber; and a passage wall extending between the elongated openings of the inner and outer enclosed walls, the openings and passage wall together forming a service passageway for access from the exterior of the assembly to the bearing chamber and forming an air passageway for a volume of ambient air to be drawn into the air passageway, into the inner enclosed wall, and out of the windband substantially surrounded by exhaust air, without the volume of ambient air entering the bearing chamber, and wherein the service passageway and bearing chamber are configured to prevent exhaust air from entering the bearing chamber from the annular space.