Flammable liquids: those that are soluble in water can be extinguished with water, while others cannot
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There are two liquids: they have similar properties and similar flash points; both are flammable liquids with medium flash points. Their densities are lower than that of water, and they are soluble in water. However, when it comes to choosing fire extinguishing agents, for one of these liquids water cannot be used to put out the fire. What is the reason for this? What other factors determine whether water can be used to extinguish a fire?
When using water to extinguish fires, the key consideration is that water should vaporize above the flame, thereby separating the flammable liquid from air and achieving the effect of extinguishing the fire; therefore, misty water must be used for firefighting, as a stream of water will not work； The two liquids have similar properties; one works while the other does not. Is there perhaps a type that can react with water and cause secondary hazards?
This post was last edited by singer.h on 2012-3-13 at 12:53. If I remember correctly, the mechanism by which water is used to extinguish fires is through cooling, right? Fogged water is probably used to ensure thorough contact between the water and the flammable liquid, thereby facilitating dilution and other purposes. I don’t think water vapor and things like that are the real cause. As for the harm to this life you mentioned, I think it’s possible indeed. It might be related to the solubility of water in flammable liquids, or perhaps to the speed of dissolution. For example, Dingtong can dissolve in 4 times its weight of water, as well as in ethanol and similar substances; both are stated to be soluble in water. But I think there must be differences between these two when it comes to their use as fire extinguishing agents. Ethanol may stop burning once diluted with a large amount of water, but butane requires a different amount of water and time to be diluted to a concentration at which it no longer burns. Hehe, it’s just my personal guess; if it’s not true, don’t blame me. I also hope to see the correct answer.
Which two liquids are they? Making it so mysterious. If you don’t tell us, how can we help you resolve your doubts? Extinguishing a fire also depends on the size of the burning area and the conditions under which the fire is occurring; for example, when only 100 grams of flammable liquid is on fire, it’s certainly possible to use a large amount of water to put it out. But when 1 ton of flammable liquid catches fire, you can’t use water to put it out. Generally speaking, water-soluble flammable liquids (such as alcohols and similar substances), although theoretically they can be extinguished by dilution with water, require a high proportion of water in the solution in order to lower their flash point enough to allow this method to be effective. This not only requires a large amount of water but also makes it easy for the liquid to spill over. Moreover, ordinary foam can be damaged by water-soluble liquids (while increasing the strength of ordinary foam can help reduce the intensity of the fire). Therefore, it is best to use flame-retardant foam for extinguishing the fire. When using dry powder or halons, the effectiveness of fire suppression depends on the size of the burning area and the conditions of the fire; it is also necessary to use water to cool the tank walls.
Tell me what these two substances are called.