RZ
Fire Extinguisher That Uses Low-Frequency Sound Waves
Two engineering students at George Mason University invented a fire extinguisher that uses sound waves to put out fires. The basic concept is that sound waves are also pressure waves that can displace oxygen as they travel through the air. At a certain frequency, the sound waves separate the oxygen that is in the fire from the fuel.
The pressure waves go back and forth, which agitates where the air is. That space can
keep the fire from reigniting.
They started off setting the extinguisher at a high frequency, but it didn't put out the fire.
Then they lowered the frequency to around 30 to 60 hertz, and the fires extinguished in
seconds.
The extinguisher uses an oscilloscope to measure the sound waves.
A frequency generator is connected to a small amplifier which is linked to an electric
power source. They are hooked up to a collimator that is made out of a large cardboard
tube with a hole at the end, which narrows the sound waves to a smaller area.
It cost around $600 for the students to make.
Their original goal and vision was to create a portable and affordable fire extinguisher that could put out kitchen fires and maybe even fires in confined areas such as a spacecraft. But because it was so quick and effective in putting out a fire, a local fire department has asked them to test their device on
a structure fire because it could replace the toxic chemicals (such as monoammonium phosphate) involved in commercial fire extinguishers.
They are now hoping the extinguisher could be attached to a drone to fight bigger outdoor fires, like forest fires. Not having to use water or foam would be helpful in many cases.
The fire extinguisher has great potential in stopping fires quickly in a variety of situations, whether it is indoors or outdoors, big or small.
It is still being tested, but it is expected to be available soon.