Development of a novel liquid fire extinguisher with film formation of silicate polymer and fire extinguishing properties

Water glass, which is a kind of the silicate compound, is relatively cheap material and is widely used as a raw material of fertilizer, synthetic detergent and binder of corrugated cardboard and so on. However, there is few research on the application of water glass for fire extinguisher using excellent function of thermo-sensitivity and polymer formation of water glass. In this study, in order to search the most suitable composition of a novel fire extinguisher using water glass and other inorganic compounds, fire extinguish experiments by the free angle splaying method was carried out to extinguish wood crib fire. The operation coefficient under these experiments was determined by the preliminary experiment using water as fire extinguisher. The fire extinguisher was prepared by dissolving aluminum silicate in water glass at optional concentration, and by dilution with water until various viscosities. The fire extinguisher splayed to fire was changed to a solid foam and/or a solid membrane on the surface of the burnt wood crib by dehydration condensation of silicate compounds caused by combustion heat. The formation of solid foam and membrane of silicate polymer on the combustibles by fire heat could be controlled by the viscosity of the fire extinguisher. The fire extinguishing ability was high at low viscosity of the fire extinguisher and high concentration of aluminum silicate in it. At this condition, it could form silicate polymer on the combustibles surface by fire heat. The cooling time until the crib temperature reached at 50 C after fire extinguishing decreased with decreasing the viscosity of the fire extinguisher.