Investigation of Extinguishment process of Liquid Hydrocarbon Flames by Aqueous Suspensions of Astralenes

Abstract

The extinguishing properties of aqueous suspensions with carbon nanoparticles (astralenes) used for extinguishment of liquid hydrocarbon flames were investigated. The extinguishment time (τ) was found to decrease by 75–80% with increasing of astralene concentrations (φ) from 0 vol.% to 0.5 vol.%. As the concentration is further increased above 1.0 vol.%, the value of τ also increases. Such changes are caused by the dependence of the latent heat of vaporization and heating rate of suspension to the boiling point on astralene concentration. The effects of nanoparticle concentration and size on nanofluid permittivity were determined. For nanofluids containing 1.0–1.5% astralenes, the permittivity was found to enhance with increasing the distances between nanoparticle agglomerates. Ultimately, these physical processes negatively affect the transport characteristics and extinguishing properties of the suspension.