Blower exhaust backflow damper methods

Abstract

Methods for preventing exhaust backflow into a blower are disclosed. Embodiments may include a blower system with an invertible blower chassis having a blower exhaust to direct airflow from the blower chassis at an airflow angle. The system may also include a backflow damper frame attached to the blower chassis and positioned to receive airflow from the blower chassis and one or more vertical damper vanes rotatably attached to the backflow damper frame. Each damper vane may freely rotate between a first, closed position and a second, open position. The damper vanes may block airflow into the blower exhaust when in the closed position and may freely rotate to a position where the damper vanes are substantially parallel to the airflow from the blower exhaust. The damper vanes may each include a vane pin to rotatably attach to frame holes of the backflow damper frame.

1  A method for preventing exhaust backflow from a blower, the method comprising:
 directing airflow through a blower intake fan having a rotational axis to a blower exhaust substantially perpendicular to the blower intake fan rotational axis, wherein the airflow is directed through the blower intake fan substantially along the rotational axis of the blower intake fan;   receiving angled exhaust airflow from a blower exhaust, the blower exhaust airflow being angled at an airflow angle between an axis perpendicular to the blower exhaust and an axis parallel to the blower exhaust, wherein the airflow angle is at an acute non-zero angle from the axis perpendicular to the airflow area and wherein further the airflow angle is substantially large such that the airflow angle is non-perpendicular to the airflow area;   rotating one or more damper vanes freely in the blower exhaust during operation of the blower; and   in the event of failure of the blower, rotating the damper vanes to a closed position via a pressure force applied to the damper vanes resulting from a lower pressure inside the blower than ambient pressure outside the blower.   
   
   
       2 . The method of  claim 1 , further comprising blocking rotation of the one or more damper vanes past a vane centerline perpendicular to the blower. 
   
   
       3 . The method of  claim 1 , wherein rotating the one or more damper vanes freely in the blower exhaust airflow comprises rotating the one or more damper vanes freely about a vertical axis substantially parallel to the gravitational axis. 
   
   
       4 . The method of  claim 1 , wherein rotating the one or more damper vanes freely in the blower exhaust comprises allowing the one or more damper vanes to rotate to an angle parallel with the angled blower exhaust airflow.