Advanced Propellant/Additive Development for Fire Suppressing Gas Generators
Stephen Fallis, Russell Reed, Paul Wierenga, Gary Holland, Yue-Cherng Lu
The Advanced Propellant/Additive Development for Gas Generator project is a collaborative effort between Primex Aerospace Company (PAC) and the Naval Air Warfare Center-Weapons Division (NAWCWD) at China Lake, CA. The objective of this NGP project is to develop new highly efficient, environmentally acceptable, chemically active fire suppressant capabilities based upon solid propellant gas generators; improve understanding of propellant and additive effectiveness in fire suppression. Cooled propellant formulations were developed based upon novel high-energy, high-nitrogen fuels in order to reduce overall combustion temperatures while maintaining ballistic robustness. These fuels included 5-amino tetrazole and the new high nitrogen compound BTATZ (C4H4N14) (courtesy of Mike Hiskey, Los Alamos National Laboratory), and were formulated with oxidizers such as potassium perchlorate or strontium nitrate, and an elastomeric binder added to facilitate pressing of pellets and increase abrasion resistance. Chemical additives are incorporated into the propellant formulations, and take advantage of the high combustion temperatures to volatilize reactive agents and/or produce them directly via the propellant combustion process. A variety of additive candidates have been identified and subsequently categorized as combustion additives (e.g. decabromodiphenylether or metal compounds such as K(acetate) and ferrocene) which take an active role in propellant combustion, and inert additives (e.g. alkali metal halides or carbonates) which undergo no substantial role in the combustion process other than to decompose thermally. Some of the identified chemical agents have been tested in a fire test fixture to evaluate their effectiveness in fire suppression for a controlled JP-8 fire. The agents were vaporized and delivered into the fire zone by high-temperature exhaust gases produced by a neutral-burning solid-propellant gas generator producing a blend of CO2, N
, Reed, R.
, Wierenga, P.
, Holland, G.
and Lu, Y.
Advanced Propellant/Additive Development for Fire Suppressing Gas Generators, Special Publication (NIST SP), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=909449
(Accessed October 6, 2022)