CO2 and Fire....

[BiG BoB]

It seems that quite a few members here run around with CO2 cylinders for pumping up tires and running air tools.

Just a thought, but as we all (should) know, CO2 is a very good fire suppressant/extinguisher (not sure on the correct term here).

Why not set up some copper/ steel pipes in the engine bay, with holes drilled down one side. Have these mounted around the outside of the bay with the holes pointing in. Set them up with a line off the CO2 tank (before the reg?) and some sort of electicaly operated solenoid. In the event of an engine fire, it should make an effective remotely operated system for extinguishing the fire.

Nobody seems to use these CO2 systems here, but it is something I thought of in my sleep last night (keep a notepad by your bed)

Sean

 

[madizell]

If you really want fire suppression under the hood, there are several professionally made systems available. Try your local fire extinguisher dealer. I priced one once for the race Jeep, and it was not all that expensive.

 

[sandalscout]

cool idea. One thing to possible explore (I simply don't know) is whether the majority of fires start under the hood, or perhaps under the dash? What about the majority of fires offroad?

You might be able to run a line under the dash (any bad side effects to activating while seated still?) and then into the engine bay.

 

[BiG BoB]

Yeah, I'm aware of the proper systems, the ones on our equipment at work are foam based and deploy either automaticaly or via a manual lever.

I've got an old diesel cruiser, so fire is less of a risk for me than someone with a petrol/gas vehicle.

Sean

 

[ntsqd]

Those systems use a dedicated nozzle in each location. I wonder how effective the holes would be?

FWIW those nozzles are available individually from places like Pegasus Auto Racing and the plumbing is usually dead soft aluminum tube, easily sourced from most home plumbing shops.
Though not technically correct, since the nozzles are AN fittings you can gently flare the tube with the more common 45* flare tool, and then form the correct flare on a steel fitting bought for use as a mandrel.

 

[obscurotron]

The only problem I see with this idea is the electrical actuation. Assume for a moment that your fire is electrical in origin - you may not have battery power now right when you need it. A manual release system (like the ones I see over exhaust hoods in restaurant kitchens) would make more sense.

Just plumb the line such that the release sits somewhere out of harms way, but within easy reach, like in a center console or even the dashboard. And whatever you do, it should be accessible while the vehicle is upside down to allow for activation in a rollover event.

All that said, I think that's a really good dual-purpose idea you came up with.

It seems that quite a few members here run around with CO2 cylinders for pumping up tires and running air tools.

Just a thought, but as we all (should) know, CO2 is a very good fire suppressant/extinguisher (not sure on the correct term here).

Why not set up some copper/ steel pipes in the engine bay, with holes drilled down one side. Have these mounted around the outside of the bay with the holes pointing in. Set them up with a line off the CO2 tank (before the reg?) and some sort of electicaly operated solenoid. In the event of an engine fire, it should make an effective remotely operated system for extinguishing the fire.

Nobody seems to use these CO2 systems here, but it is something I thought of in my sleep last night (keep a notepad by your bed)

Sean

 

[BiG BoB]

Yeah, my idea is that if you have a few pound cylinder of CO2, then it should be enough to displace the oygen from the engine bay if it was being dumped in un-regulated.

Might not stop the vehicle from going up in flames once the gas run out, if it was still hot enough to ignite vapours, but might give a short amount of time to get out, and grab survival gear

Sean

 

[ntsqd]

FWIW those systems that are electrical have their own battery. They're not dependent on the vehicle for power.

 

[madizell]

Even if the fire is electrical in source, a fire rarely compromises electrical power. That's why disconnecting the battery under the hood of an auto after a collision is important. But a mechanical actuation would not be dependent on power, and presumably the suppressant bottle will have pressure enough to do the job once activated. I didn't get that far into the systems when I looked at them, but they are intended for race vehicles and other such applications, and the dynamics will have been worked out, or they would be of no value. Anyway, the thought was that it was not necessary to reinvent the wheel when well thought out systems are available for a reasonable cost.

As for CO2 under the dash -- not if you still occupy the vehicle and can't get out. CO2 is not all that nice to breathe. I think it was Dave Letterman who one time decided it would be fun to wear a suit with Alka Seltzer tablets stuck all over it, then jump into a tank of water. A human fizzy if you will. Someone was not thinking. He nearly died from asphyxiation before he could be rescued. The tablets release CO2.

 

[devinsixtyseven]

It actually sorta hurts to breathe CO2...I wouldn't recommend it at all.

Along the same lines as what you guys are suggesting, how about a nozzle on a quick-disconnect to use the bottle like a regular fire extinguisher? I figure that's gotta be pretty easy? Can you just use a squirter-style nozzle or does it need to be a specific shape for dispersion?

-Sean

 

[ntsqd]

The big problem there would be the phase change. CO2 going from liquid to gas would freeze-burn you if you had your hand on a thermally conductive nozzle. Solve that issue and you've got a reasonably viable system.

 

[madizell]

Wouldn't it be easier and cheaper just to buy a few fire extinguishers?

 

[ntsqd]

I'm thinking that if the right parts were sourced and kept handy that this could be the back-up plan rather than an outright replacement.

 

[devinsixtyseven]

Not squirter as in liquid, squirter as in directed gas flow. I use one of these things to get dust off stuff...

 

[ntsqd]

Using CO2 to run impacts & what-not in the Locos Mocos Baja pits we always had 2 bottles set up and ready to go. Was common to freeze up a regulator and have to swap the hose. That is what is fueling my concern over the phase change from liquid to gas. Even if the actual change is happening in the bottle, the gas coming out of the bottle will be really cold and has the potential to cause freeze burns.