The aqueous film-forming foam fire extinguishing agent can prevent the spread of the fire and achieve the purpose of extinguishing the fire. In firefighting, everyone must have a certain understanding of aqueous film-forming foam liquid, so let us introduce his fire-fighting principle and his brief introduction in detail.
Aqueous film-forming foam is also known as light water foam fire extinguishing agent, abbreviated as AFFF in English. Fluorocarbon surfactants are mainly used, and foam stabilizers, preservatives, high molecular polymers, etc. are added. Fluorine-containing surfactants can significantly reduce surface tension, and have high heat resistance and chemical resistance. When used in combination with hydrocarbon surfactants, they show a good synergistic effect and can effectively reduce the surface tension of the solution. , reduce the oil interfacial tension. The mixing ratio of foam plastic fire extinguishing agent and water is AFFF3% type and AFFF6% type.
Fire fighting principle
The water-forming foam fire extinguishing agent is foamed in an aqueous solution, and its water solubility is lighter than water, so it can float on the surface of the burning liquid, so it is called "light water foam fire extinguishing agent". Environmentally friendly aqueous film-forming foam fire extinguishing agent is better than protein foam and fluoroprotein foam in extinguishing oil and Class B fires. Its extinguishing principle, in addition to the function of general foam fire extinguishing agent, also precipitates liquid cooling liquid surface at the same time as the surface of the burning liquid spreads, and forms a layer of water film and foam layer on the surface of the burning liquid to jointly seal the surface of the burning liquid and isolate the air. It forms a heat insulation barrier, and the heat-absorbed liquid evaporates to dilute the oxygen content in the air on the burning liquid surface, and suffocates the burning liquid, so that the burning liquid cannot continue to heat up. Evaporates and burns. The fundamental difference between it and other fire extinguishing agents is that the "aqueous film-forming" foam fire extinguishing agent has dual fire extinguishing effects of foam and water film, which is the reason for its high fire extinguishing efficiency and short time.
