Sound and Electricity for Putting Out FiresCategory: Science & Technology
Posted: July 16, 2012 11:51AM
There is a reason we are told not to play with fire; because it can destroy and damage many things and be very hard to stop. Despite this for about 50 years, no new ways to control and put out fire have been developed. Researchers at DARPA decided that was too long a time back in 2008, so they started the Instant Fire Suppression (IFS) program to create new ways to control fire and increase our understanding of it.
Modern fire-suppression technologies operate on the chemistry of the flames, such as removing oxygen from the area to stifle the combustion. Physically though fire can be thought of as a cold plasma, so the researchers decided to target it that way by using an electrode to suppress flames. The electrode ionizes the gases around it, creating a wind that blows out the flame.
The researchers also used two large speakers to disrupt flames by spreading them and the fuel out over a larger area. Spreading the flames like this causes the area of combustion to thin, which makes it more susceptible to other disruptions. The sound also causes more of the fuel to vaporize, which widens the flame and drops the temperature of the fire. Essentially the same amount of heat has to ignite more fuel, which causes the temperature to drop until it is too low to maintain combustion.
While the IFS program has definitely learned more about fire from these experiments, it is not clear exactly how they could scale these methods up. However, we can still benefit from these findings as others can use them to create new ideas to not only suppress fires, but possible improve their efficiency as well.