ACOUSTIC FIRE SUPPRESSION
September 12, 2023
On July 2, 2013, in response to some devastating wildfires in the news, I wrote the following in another forum: "I know there has to be a bright chemist out there with the resources and know-how to develop a substance to help douse wildfires. A substance that's non-toxic in its original state and biodegradable in post-application, and that can outpace the flames when necessary." But in retrospect, perhaps the future of firefighting isn't a chemical substrate. Heaven knows certain man-made concoctions have already done enough harm to people throughout the years from all walks of life.
ACOUSTIC FIRE SUPPRESSION On April 2015, multiple outlets including physicsworld.com broke the news of two talented George Mason University students who developed an acoustic fire extinguisher for their senior research project.. Seth Robertson and Viet Tran discovered that using low audio frequencies (30-60 Hz) can actually separate the oxygen from the other components of a fire! And Lisa Wirthman on Dell.com reported on March 10, 2020 that Suchinder Paul Dhillon has been working to expand this concept with a force multiplier to serve as a non-chemical protective barrier for neighborhoods against incoming wildfires.
While this technique has an abundance of advantages (no refills required, no toxic chemicals…), as well as its limitations (some doused fires can restart due to leftover heat in the combustible materials), I'm wondering if perhaps someday we could possibly reduce the size of these acoustic devices and implement them in corporate buildings. The Speed of Sound: Mathisfun.com states that sound travels more than 4,000 meters per second through glass and almost 6,000 meters per second through steel! (…By comparison, sound travels through air at a rate of only around 350 meters per second, depending on the temperature.) What if we took advantage of that fact and juxtaposed a version of these acoustic fire extinguishers to reverberate right through such solid materials at key locations? I don't know if the physics of audio waves change when sound passes through these types of solid materials into the air. Does the frequency change? Does it decrease in intensity? Is there any resulting acoustic dispersion? And would ongoing emission of any of these frequencies adversely affect human hearing or disrupt surrounding wildlife in any way? Clearly, this type of sonic device and any side-effects would need to be studied and tested thoroughly. But since businesses often have important papers & electrical equipment that can be damaged in the event that overhead water sprinklers are activated, perhaps acoustic fire suppression can be an alternative option to at least control an unexpected fire until human help arrives. (Apart from that, acoustic speakers enclosed within walls would also have the added benefit of boosting audio quality for in-house dance parties during special events. 😂)
