In a paper that was presented to a meeting of the American Chemical Society, Harvard scientists said that they have successfully used an electric wand to put out a fire. This leads to hopes that firefighters could some day be able to carry a power source in a backpack and fight with electricity rather than water.
In one scenario, if a wall of flame prevents getting from one place to another, the beam of electricity could be used to part the flames and pass through. The new method would be able to give the flames a good zap of electricity rather than drenching the contents of a room with the highly destructive water that comes from traditional fire sprinklers.
It has been known that electricity can change the shape of flames, by bending, twisting, or even moving them away from their source of fuel and thus, snuffing them out. This is how the new technology could work. Now that hand held tasers can produce power, it is conceivable that the power of a car battery can be carried in backpacks. This way, electricity would become portable enough to shoot beams at fires in strategic ways.
But up to now, there has not been enough research into using electricity to alter the conduct, connection to the fuel source, or shape flames. The scientists who carried out the study were led by Ludovico Cademartiri, Ph.D., and his colleagues.
The scientists are in the group of George M. Whitesides, Ph.D., at Harvard University. The study was funded by the Defense Advancement Research Projects Agency and the US Department of Energy. The American Chemical Society is a nonprofit organization that is chartered by the US Congress.
Current technology involves starving the flames by eliminating oxygen. This requires the use of water, foam, powders or other materials and is done up close. Using electricity, firefighters could work from a distance or use command and control systems to conduct remote firefighting.
The study produced immediate effects and worked again and again to snuff flames. A wand device was connected to a 600 watt power amplifier and aimed at a foot high flame. The flame was successfully moved away from its power source and repeatedly extinguished. Dr. Cademartiri believes that much could be done with as little as a tenth of that power, or 60 watts.
The workings of this incredible discovery are based in the carbon soot particles that are produced by fire. It is the soot particles that are easily charged with electricity and that cause flame movement or changes to the flame structure. In other words, electrically charged soot particles change the structure of the flames.
Such study could lead to the opposite of extinguishing fire: making fire more efficient in controlled and desired combustion such as welding, car engines, jet engines, power plants and possibly even open flame cooking and baking!
The fire fighting and suppression possibilities are far more promising for fighting fires in smaller or enclosed areas or for parting walls of flame in order to move through and save people or to escape. Large fires like forest fires are, of course, not as well suited for such fire suppression.
But there are many more complexities to the chemical nature of fire and combustion. Dr. Cademartiri and his colleagues feel that much more needs to be done by the chemistry community in order to better understand the chemistry of combustion and fire.
