FYFD

Tag: fire suppression system

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    How Fire Sprinklers Work

    Most of us have probably never given much thought to how a fire sprinkler works, but fortunately, the Slow Mo Guys have used their high-speed skills to answer that question anyway. Sprinkler systems of this variety are constantly pressurized by a full pipe line of water that’s held back by a thin metal disk and a colored glass ampule containing a fluid like alcohol. The color of ampule indicates the temperature at which the system is designed to activate. As the ampule heats up, the fluid inside expands, breaking the ampule at or near the critical temperature. That allows the metal disk to fall away and releases a torrent of water, which falls onto the gear-like disk at the bottom of the sprinkler and gets flung out over a wider area. Despite appearances, that bottom disk is stationary, not spinning; its shape alone is what distributes the water. (Image and video credit: The Slow Mo Guys)

  • Putting Out Fires

    Putting Out Fires

    Fires in large, open spaces like aircraft hangers can be difficult to fight with conventional methods, so many industrial spaces use foam-based fire suppression systems. These animations show such a system being tested at NASA Armstrong Research Center. When jet fuel ignites, foam and water are pumped in from above, quickly generating a spreading foam that floats on the liquid fuel and separates it from the flames. Since the foam-covered liquid fuel cannot evaporate to generate flammable vapors, this puts out the fire. 

    The shape of the falling foam is pretty fascinating, too. Notice the increasing waviness along the foam jet as it falls. Like water from your faucet, the foam jet is starting to break up as disturbances in its shape grow larger and larger. For the most part, though, the flow rate is high enough that the jet reaches the floor before it completely breaks up. (Image credit: NASA Armstrong, source)