I’ve been thinking about integrated fire suppression. Not for leaving the machine unattended! Not for replacing a dedicated CO2 fire extinguisher! But I have a 24oz CO2 canister sitting around unused, and see some potential benefits. I probably won’t ever get around to it, but it’s fun to think about.
Could be two-stage. If I monitor flare-ups, I could dump CO2 into the air assist alone to put out a fire before it spreads; could also have a second stage that floods the whole enclosure with CO2.
Can keep a lid on it: Don’t need to open the unit and provide more O2 before setting off a CO2 extinguisher.
If I can find a reasonable price on 1000 psi solenoids, could be triggered automatically; first stage could be triggered by IR camera seeing more pixels light up than expected; second stage could be triggered by temperature sensor at exhaust, which if it triggered would also turn off the exhaust fan (and close a blast gate, if configured) to stop feeding the fire.
I see that paintball CO2 regulators take 4500psi canisters down to 800psi; probably an inexpensive small orifice downstream of that would be fine for the first stage for flare-ups, and a much larger orifice through a manifold and out through a network of copper pipes to flood the box.
This seems to me obvious enough that it must have been done before, or at least talked about before, but search terms I can think of aren’t helping me much. A full-sized CO2 extinguisher intended for open fires is often 5 lbs. I’d think that in an enclosed space, 1.5lbs of CO2 would be sufficient in most cases, and might avoid needing to recharge a full-size extinguisher some day.