CO2 Fire Prevention Safety: Invisible Dangers of CO2 Discharge

Posted by ORR Protection on Dec 4, 2020 12:00:00 PM

During the MCFP Virtual Conference series, Rick Reynolds, Vice President of Engineering and Training at ORR Protection Systems, discusses CO2 discharges with a video showing the process. Part 2 of 4.

CO2 Fire Suppression Safety

Video Transcript:

That's the reason and why NFPA 12 was reorganized or was fitted for today's time, and the refitting had to happen. And unfortunately that number continues to be there, and it continues to rise. And if you see two thirds of those deaths is probably because of the would-be rescuers, you know, and, and those would-be rescuers are the folks that see a man down or a lady down. And they ran in to try and rescue them. And that's the problem. And so we all have to be very cautiously aware of, you know, knowing that, hey, there's somebody down, I'm going to go get him. Well, CO2 is an invisible agent. So once it discharges, then the temperature comes up and the, and the atmospheric temperature of those molecules get, and it dissipates to tent room temperature. Then you can't see CO2. So you don't know what the concentration is in that space.

You may run into a highly concentrated area and you're not knowing it. And then all of a sudden you can become overcome with that same high level of concentration to CO2. So really, really gotta be careful with CO2. It's an awesome agent, good firefighting, good ability to suppress. Remember, it'll take out all three sides of the fire triangle, but we have to be very cautious in doing that. So, the proficiencies. ORR put together this little chart, and if you'd like a copy of this and you want us to send it to you, we'd be happy to. All of our PowerGen customers, we try and give this to them, to post on their bulletin board. Just as a reminder, it's not a bad thing to have it out there. As a reminder, it's not a scare tactic. It's a reality that CO2 is a reality.

1%. Do you see the chart? The correlation 3%, 5% and above 8%, let's be honest. There's some really, really—things that happen there, the unconsciousness and so forth. And so now we're going to actually show you a complete discharge. And during this discharge sequence, we're going to show you the electronic audibles and you'll see the strobe in the background. And then we're also going to be able to hear the pneumatic siren, which is part of that NFPA 12. And then we'll hear the, um, discharge. You'll be able to see the discharge coming out of a nozzle, and then we'll be able to watch the entire cycle.

Now, of course at ORR we, you know, we've shortened this discharge for time sake, but there are numerous folks, when I've done interviews across the actual portfolio of ORR, that have had CO2 protected zones and protected hazards, what we call hazards for many, many years that have never seen a CO2 discharge and video in real live form. So being able to see this is really impactful, and there's some key elements that I'll point out along the way, but let's watch this together because I think you're going to be able to see some things that will also enhance the idea of why NFPA actually went to the extreme of doing some of the safety enhancements on the standard that they needed to, because of what I've actually showed. You are shown all of the safety enhancements that are required now. So let's, let's watch this together. So this is, like I said, it's a lube oil skid, and it's the discharge test that we actually provided for a customer of ours.

So that is the audible circuit of the electronic audible. You see that strobe in the background that's going off. So I'm going to turn it up just a little bit. So in that you can hear that the audible circuit is, and the reason why you'll hear a pneumatic siren start up in just a second. Think of this, where if the audible circuit was shorted out, or it did not work, then all of a sudden you would have CO2 coming into the space unprotected. So that's why they want this pneumatic siren in there. So now that pneumatic siren is powered by CO2 or even by nitrogen. So it's a very loud sound in the space. So that siren needs to be inside the space, according to the code, as it says, it typically runs for about 30 seconds or however long it takes for somebody to evacuate that space.

So it's running for 30 seconds now, and that's the actual time that we're, we're being able to witness it. Now we have CO2 discharge. So you'll see in that back nozzle back there, here it comes. And it will actually, as it discharges within the space, then we have a complete visual obscuration within about 12 seconds. And so as the system discharges, complete whiteout, complete obscuration, and if you were in the space, that concentration just went up to beyond the, we would have displaced all the oxygen in the space by now, or it got the oxygen level well below flame front of what it can actually sustain flame front.

So at this point, this particular lube oil skid required, three minutes initial and a 40 minute extended discharge. So we're adding a little bleeder nozzle in there that would have been actually bleeding CO2 into this space for 40 minutes to maintain that concentration. That's what's so unique about CO2. We can extend that discharge for that duration. Now we'll also what you'll start seeing is CO2 will start dissipating in visualization where you'll think, okay, well, I'm okay to go into that space, but remember CO2 visualization or CO2 gas, once it comes up to temperature, it's an invisible agent. So you don't know what the concentration of agent in that space really is. And that's where that, that hazard really starts coming into play. That's where those would be rescuers come into play, where they're actually going down. So, and then on the screen, you'll see in just a second, where we actually bring up that of course toxicity chart, where we really want to remind folks about that toxicity.

And then of course the versatility of CO2. But again, when we're talking about CO2 and we're talking about migration of CO2, if we, you were discharging for 40 minutes and that extended discharge, think about how much CO2 could be migrating outside of that, those leak and closable openings, those leak areas where it may leak into the next little compartment. And if you were walking up to that zone or into that area, you could be walking into a highly enriched or an enriched concentration of CO2. So that's why it's very important for oxygen monitors and making sure that you understand, man, that, "Hey, am I in a oxygen in deprived environment?" So this video has been very, very useful to a lot of training classes. And if you would like a copy of this video please reach out in the question and answer session. I'd be happy to share this with you and with your team. So that way you may be able to share that with your onsite personnel as well at your leisure. So very good, very good data there.

So NFPA, 2012, the impact of changes, let's talk about that. What has changed, and why did it change, and how is it developing for you as the CO2, maybe a CO2 system owner, or maybe as the EH&S personnel at the plant or, somebody that's actually a responsible person at the actual company or you're the authority having jurisdiction. And what do I need to be looking for in these systems that are already installed? Remember NFPA 12 is retroactive. So that means that any system that was installed from point 0.0 all the way until 2009 and 20, this is all retroactive.

What do I need to be looking at as well as the authority having jurisdiction? So, and the reason for change, again, life safety, I cannot stress that enough. It's about the life safety of personnel and the life safety of the folks around that could actually be impacted by this CO2 being discharged. So it was for both new systems and existing systems. Like I said it's retroactive. I can't stress that enough. So how are we going to accomplish this? We're going to look at all, all types of systems, the system, actuation devices, we're going to look at modifications that have been done to the system. So what types of systems are affected while the total flood systems? And that's just like the lube oil skid that you see those are total flood, we're totally engulfing, or totally flooding that space. Total flood systems applied to normally occupied and non occupiable spaces. So those are very, very key words to know about.

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