Inventors:
Jason Thomas Stoll - Rochester MN
Maurice Francis Holahan - Lake City MN
Dale Lidberg - Alexandria MN
Assignee:
International Business Machines Corporation - Armonk NY
International Classification:
H05K 500
Abstract:
A fan check valve is formed from plastic film having an outer edge and a central region. The valve also has a number of slits that define flaps in the film. The flaps are symmetrically arrayed in a spiral-like pattern between the central region and the outer edge. The valve mounts to the outer surface of a tube axial fan. Under normal operating conditions, the fan moves a helical flow of air in a generally axial direction toward through the valve. The flaps are blown open and align with the oncoming flow at low angles of attack to minimize dynamic losses. The flaps are in the closed position and lie flush on the outer surface of the exhaust plate mounted on the fan at all other times to prevent airflow back through the fan in the opposite direction once the fan has failed.