Condensed aerosol fire suppression is a particle-based form of fire extinction.
It employs a fire-extinguishing agent consisting of: very fine solid particles as well as gaseous matter. The condensed aerosol microparticles and effluent gases are generated by the exothermic reaction; the particles remain in vapor state until the process of being discharged from the device. Then, it is “condensed” and cooled within the device and discharged as solid particles.
Compared to gaseous suppressants (which emit only gas) and dry chemical suppression agents (which are powder-like particles of a large size – 25–150 micrometres), the National Fire Protection Association defines condensed aerosols as those that release finely divided solids of less than 10 micrometres in diameter.
The solid particulates have a considerably smaller mass median aerodynamic diameter (MMAD) than those of dry chemical suppression agents. The particulates also remain airborne significantly longer and leave much less residue within the protected area.
Condensed aerosols are flooding agents. They are effective regardless of the location and height of the fire. This can be contrasted with dry chemical systems, which must be directly aimed at the flame.
The condensed aerosol agent can be delivered by means of mechanical operation, electric operation, or combined electro-mechanical operation.
Condensed aerosols’ primary extinguishing mechanism involves the fourth element of the fire tetrahedron by means of chemical reactions with the free radicals of the flame, therefore interfering with the combustion process of the fire. Typically, condensed aerosol particulates consist of potassium carbonate (K2CO3)) that are produced from the thermal decomposition of a solid aerosol-forming compound that includes potassium nitrate as an oxidizer. As the aerosol particles surround and come into contact with the flame, the particulates absorb the flame heat energy, breaking down and releasing large concentrations of potassium radicals (K+) (ions with an unpaired electron). The potassium radicals bond with the hydroxide (OH+), hydrogen (H+) and oxygen (O+) free radicals that sustain combustion, producing harmless by-product molecules like potassium hydroxide (KOH) and water (H2O).
K• + OH• = KOH
KOH + H• = K• + H2O
The potassium radicals are propagated since they are both consumed and produced by reaction with the fire radicals. Disrupting the reactions necessary to sustain the flame’s combustion, the cycle continues until the combustion’s chain reactions are terminated and the flame is extinguished.
Features:
• Fast acting
• No Ozone depleting Potential (ODP)
• No Global Warming Potential (GWP)
• Requires minimal storage space
• Cost Effective
Applications:
• Archive stores
• Lithium Ion Battery Containers
• Electrical Cabinets
• Generator /CHP Enclosures
• Petrochem facilities
• Offshore
• Gas turbines
• Power generation
• Industrial Machinery