Using low-frequency sound waves to put out flames, this experimental fire extinguisher is the work of George Mason University engineering seniors Viet Tran and Seth Robertson. Watch as they Pump Up the Bass to Douse a Blaze. From The Guardian:
The basic concept, Tran said, is that sound waves are also “pressure waves, and they displace some of the oxygen” as they travel through the air. Oxygen, we all recall from high school chemistry, fuels fire. At a certain frequency, the sound waves “separate the oxygen from the fuel. The pressure wave is going back and forth, and that agitates where the air is. That specific space is enough to keep the fire from reigniting.”
So the trial and error began. They placed flaming rubbing alcohol next to a large subwoofer and found that it wasn’t necessarily all about that bass, musically speaking, at least. “Music isn’t really good,” Robertson said, “because it doesn’t stay consistent.”
They tried ultra-high frequencies, such as 20,000 or 30,000hz (hertz, or cycles per second), and could see the flames vibrating but not going out. They took it down low, and at the range of 30 to 60hz, the fires began to extinguish.
While the technology isn’t yet consistent or thoroughly tested, there’s potential for this concept to be a game changer: Imagine keeping firefighters safe when sound wave-equipped drones can put out a burning building. Imagine not having to use the toxic chemicals that are currently in fire extinguishers. Imagine waterless extinguishers for stopping forest fires during droughts. Are solutions like these possible?
The Defense Advanced Research Projects Agency (DARPA) was pursuing instant fire suppression as early as 2008, but the 2011 machine, above, was not practical for everyday emergencies. Now preliminary patent application holders, Robertson and Tran are continuing to improve on their portable and potentially low cost firefighting invention.
Watch these next: The Fire Lab and the Mysterious Science of Fire, ExpeRimental Candle Chemistry, and Science + music = audio frequency visualizations.
“Engineering is really just finding solutions for complicated problems… Engineering is about finding a way to make the impossible possible…”