Patent ID: 7509968
Filing Date: 2009-03-31
Classification: A62C,B64D,B65D,Y10T

Abstract:
1. A method of controlling oxygen content within and aircraft fuel tank ullage, said method comprising the steps of: (a) determining a rate of change in oxygen content within the fuel tank ullage based on atmospheric pressure and temperature of an environment outside of the aircraft and external of the fuel tank ullage, wherein the atmospheric pressure and temperature of the environment outside of the aircraft and the fuel tank ullage are measured by sensors disposed outside of the fuel tank ullage; (b) determining a desired flow rate of nitrogen-enriched air required to minimize oxygen content within the fuel tank ullage based on the atmospheric pressure and temperature of the environment outside of the aircraft and external to the fuel tank ullage; and (c) controlling an actual flow rate of nitrogen-enriched air responsive to said determination of said desired flow rate of nitrogen-enriched air by modulating a control valve disposed between an air separation unit and the fuel tank ullage.