AVS 61st International Symposium & Exhibition
    Plasma Science and Technology Thursday Sessions
       Session PS+SE-ThA

Paper PS+SE-ThA4
A Novel Atmospheric Pressure Plasma Application for Fuel Tank Inerting

Thursday, November 13, 2014, 3:20 pm, Room 308

Session: Atmospheric Pressure Plasma Processing; Fundamental and Applications
Presenter: Matthew Price, Interspace, Inc.
Authors: M. Price, Interspace, Inc.
A. Srivastava, Interspace, Inc.
Correspondent: Click to Email
Aircraft fuel tanks have traditionally been protected from ballistic threats caused from explosive vapors by filling the area above the fuel with suppressant foam or inert gas. More recently fuel tank inerting systems have been developed for commercial transport aircraft. Inert gas is the preferred method since foam is heavy, reduces fuel tank capacity and is expensive to maintain. Current solutions consist of Onboard Inert Gas Generation Systems (OBIGGS) to reduce oxygen content in fuel tanks through the use of nitrogen-air separators. These membrane-based separators require high-powered pumps to flow air through small pores in the membranes. OBIGGS systems are bulky and too power hungry to be practical for smaller aircraft with multiple fuel tanks and limited electrical power. INTERSPACE has developed an innovative and efficient inerting system that does not rely on a pre-stored inerting agent or bleed air and is scalable to support multiple independent tanks. The system requires minimal electrical power and is capable of inerting to trace oxygen concentration levels without contaminating the fuel.

Our solution uses a getter material to readily sequester oxygen as surface oxides. A non-thermal, atmospheric pressure plasma then combines hydrocarbons in the tank with the getter to reduce the oxide and reverse the process to form water vapor. No consumable inerting product is used. Experimental data shows the getter absorbs 20 times its volume in oxygen before saturation. Scaling up this reaction would inert a 500 gallon fuel tank in 11.4 minutes with one liter getter at standard temperature and pressure conditions. Time-to-inert decreases at higher altitudes due to lower pressure. Time-to-inert curves were calculated for the typical aircraft flight envelope based on this model. We have successfully demonstrated the feasibility of our inerting system in a laboratory environment. Our inerting system is highly selective to oxygen, and eliminates the membranes and high power pumps used in existing systems. The next step will be to evaluate a prototype system through demonstration testing on the replica of a military aircraft fuel tank system. A customized plasma source will be developed optimized in size and weight competitive with aircraft applications.