A novel hot aerosol extinguishing agent with high efficiency for Class B fires

A novel hot aerosol extinguishing agent (HAEA), which is the combination of pyrotechnics and flame retardant technology, was found to have great efficiency in extinguishing Class B fires. A mixture of P and P₃N₅, referred to as P90x, was chosen as the reductant, and phase stabilized ammonium nitrate was chosen as the oxidant. This paper describes a study of the effectiveness of this agent in extinguishing n-heptane fires (ie, Class B fires). We determined that the best efficiency was 15 g/m³ for extinguishing n-heptane fires, four times more efficient than a traditional agent. The efficiency increases as the mass fraction of P90x rises. We also identified the key difference between the novel extinguishing agent and the traditional agent. The former consists of an inorganic phosphorus compound, while the latter is mainly comprised of KOH. Consequently, their extinguishing mechanisms are different. The phosphorus oxide of the novel HAEAs is the leading component to extinguish fire, which is more effective than alkali salts.