Oxygen concentrator
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broncobowsher
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Craig's list search for "oxygen" will get a lot of results. Sometimes pretty cheap when the family is trying to clean out grandma's old stuff after she is gone.
Thought about them, but the Argon is what drives me away.
Thought about them, but the Argon is what drives me away.
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@jale if you check the thread I linked it shows a lot of what you're looking for. If you are in the US, the glass blowing forums are good places to check. I got my setup for under $200 on facebook marketplace and it included several of the tanks which are important to get the QD adapter. Those are very expensive to buy separately. The rest of it was about $200 for the fill whip and parts and got all except the DIN adapter at my local hydraulic hose supplier. ORB adapter, SS/Teflon braided hose, etc.
@broncobowsher if you are doing OC stuff, do not worry about the argon. It's not in any sort of concentration to have an impact on narcosis or decompression. It is the standard way of creating nitrox in most of the world but is done from much larger PSA machines. I have "real" O2 that I use with my rebreather for drive gas, but all of my offboard O2 is from the homefill
@broncobowsher if you are doing OC stuff, do not worry about the argon. It's not in any sort of concentration to have an impact on narcosis or decompression. It is the standard way of creating nitrox in most of the world but is done from much larger PSA machines. I have "real" O2 that I use with my rebreather for drive gas, but all of my offboard O2 is from the homefill
Educate me.... what are teh limits for argon such as in PP. For the amount you add for a 32% mix would bring argon up from 1% to about 1.6 % argon? My understanding of it may be wrong but argon should have no detrimental issues as such low pp argon.
here are a couple of statements i easily found on the net
Although argon is non-toxic, it is 38% denser than air and therefore considered a dangerous asphyxiant in closed areas. It is difficult to detect because it is colorless, odorless, and tasteless.
and
The effect of simple asphyxiant gases is proportional to the extent to which they diminish the amount (partial pressure) of oxygen in the air that is breathed.
not picking a fight just looking to learn.
I understand to a point a concern for using 96% deco gas with 4% argon in it. Maybe.
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@KWS argon is ~2.5x as narcotic as N2. You obviously don't need it so low is fine. As for high, it's an inert gas just the same as helium and nitrogen so there is a decompression factor, but since it's already 1%, the difference to 1.6% is essentially negligible, no different than ignoring half a percent of N2 when doing nitrox analysis. In nitrox or trimix mixes? It's irrelevant IMO. Not a physician, but it's been used around the globe for decades with no ill effects. If you have ever breathed nitrox made with a membrane, it does the same thing.
Now, as far as using it for pure O2? It's the standard for oxygen concentrators for breathing at the surface, and I have put plenty of hours on it as a deco gas and have never noticed any difference. I don't change my fO2 when using it for 100% O2 either as the argon is still displacing nitrogen and helium in the breathing mix which is what matters.
Now, as far as using it for pure O2? It's the standard for oxygen concentrators for breathing at the surface, and I have put plenty of hours on it as a deco gas and have never noticed any difference. I don't change my fO2 when using it for 100% O2 either as the argon is still displacing nitrogen and helium in the breathing mix which is what matters.
broncobowsher
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I don't know of any published limits for Argon. It is inert, like Nitrogen. For open circuit I could care less. It was something pretty much glossed over in my Nitrox class. Normal Nitrox is used relatively shallow, there is only a little bit blended into air. Running a little extra Argon, you might get 2%, doesn't really change anything. A Nitrox mix so strong that you have 2% will be so depth limited you are not close to getting narced.
But for a rebreather things get different. The oxygen is to replace what you metabolize. If you are putting 5% Argon in with your Oxygen (That is what you should expect as you remove the 79% (call it 80% for easy math) Nitrogen and you have Oxygen and Argon now 5X stronger). So 5% of your oxygen is Argon, you burn the Oxygen but leave the Argon. Add more Oxygen/Argon. Pretty soon the Argon in the loop can be a rather significant percentage. If you are running Helium as an anti-narcotic gas, but silently a heavily narcotic Argon into the mix, I am not comfortable with that. The flush every 15 minutes advise, hope you remember before you get narced and forget to. I would rather just use a 100% if I can. I only know of one rebreather (Liberty) that run helium sensors, everything else just uses a little math and you program the trimix in the Diluent bottle and Oxygen is the variable measured with Oxygen sensors. IF you start blending another gas into the mix, the rebreather still knows how much oxygen is in the mix but the computer doesn't know the Nitrogen/Helium/and now more then a trace of Argon in a variable amount that changes depending on how recently you have flushed the loop.
It isn't that it is heavy. There is plenty of velocity in the lungs to expel Argon you inhale. It isn't going to magicly settle and not be able to get it out. SF6 (Sulfur Hexafluoride) is really dense and there are plenty of YouTube videos of people breathing that in for the deep base voice (opposite of Helium) and they are not doing handstands to expel it when they are done. Couple of breaths and back to a normal voice, the gas is gone. Even Propane is a simple asphyxiant, just happens to be flammable. If it is a gas, it will vent out the lungs just fine. When you get into liquids in the lungs, that is a problem. Or if there isn't enough Oxygen in the gas.
But for a rebreather things get different. The oxygen is to replace what you metabolize. If you are putting 5% Argon in with your Oxygen (That is what you should expect as you remove the 79% (call it 80% for easy math) Nitrogen and you have Oxygen and Argon now 5X stronger). So 5% of your oxygen is Argon, you burn the Oxygen but leave the Argon. Add more Oxygen/Argon. Pretty soon the Argon in the loop can be a rather significant percentage. If you are running Helium as an anti-narcotic gas, but silently a heavily narcotic Argon into the mix, I am not comfortable with that. The flush every 15 minutes advise, hope you remember before you get narced and forget to. I would rather just use a 100% if I can. I only know of one rebreather (Liberty) that run helium sensors, everything else just uses a little math and you program the trimix in the Diluent bottle and Oxygen is the variable measured with Oxygen sensors. IF you start blending another gas into the mix, the rebreather still knows how much oxygen is in the mix but the computer doesn't know the Nitrogen/Helium/and now more then a trace of Argon in a variable amount that changes depending on how recently you have flushed the loop.
It isn't that it is heavy. There is plenty of velocity in the lungs to expel Argon you inhale. It isn't going to magicly settle and not be able to get it out. SF6 (Sulfur Hexafluoride) is really dense and there are plenty of YouTube videos of people breathing that in for the deep base voice (opposite of Helium) and they are not doing handstands to expel it when they are done. Couple of breaths and back to a normal voice, the gas is gone. Even Propane is a simple asphyxiant, just happens to be flammable. If it is a gas, it will vent out the lungs just fine. When you get into liquids in the lungs, that is a problem. Or if there isn't enough Oxygen in the gas.
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@broncobowsher correct, however when you are diving over seas, you don't always have the luxury of pure O2, most places in Asia are using PSA machines to get their "O2". The military also uses PSA machines for their rebreathers in a lot of locales which is why the Meg is set up to calibrate with less than 100% O2.
Is it a good idea to use? Depends on what is available at the time. If it means not diving and doing a 15 minute flush? No problem. Some rough math. Full loop volume is say 10l. You use 1lpm of O2, 0.06 of which is Ar. Diving at the surface, so you start out with .6l of Ar in the loop or 6%. After 15 minutes, you will have added 15*.06=.9l. 1.5l/10=15% which is worst case scenario since it would be proportionally less with depth. That's equivalent of 35% of N2 from a narcosis perspective so not going to be that bad of a narc. Say you were at 70ft breathing 50/50, if the same 15% of Ar was in the loop, added to the 50% of N2, that would be equivalent of 85% N2 which is marginally more than air. To get to 15% Ar in the loop at that depth would take well over an hour without a dil flush.
Is it enough to matter? Military doesn't seem to think so and you certainly won't be narc'd out of your mind before you remember to dil flush
Is it a good idea to use? Depends on what is available at the time. If it means not diving and doing a 15 minute flush? No problem. Some rough math. Full loop volume is say 10l. You use 1lpm of O2, 0.06 of which is Ar. Diving at the surface, so you start out with .6l of Ar in the loop or 6%. After 15 minutes, you will have added 15*.06=.9l. 1.5l/10=15% which is worst case scenario since it would be proportionally less with depth. That's equivalent of 35% of N2 from a narcosis perspective so not going to be that bad of a narc. Say you were at 70ft breathing 50/50, if the same 15% of Ar was in the loop, added to the 50% of N2, that would be equivalent of 85% N2 which is marginally more than air. To get to 15% Ar in the loop at that depth would take well over an hour without a dil flush.
Is it enough to matter? Military doesn't seem to think so and you certainly won't be narc'd out of your mind before you remember to dil flush
Someone educate a dumb plumber here please....
Why do you get argon when using a concentrator?
Why do you get argon when using a concentrator?
Air is partially argon and concentrates with the O2
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Air is composed roughly of 78% N2, 21% O2, and 1% Ar *all rounded obviously*.
The process used to "filter" out the nitrogen in these concentrators is called pressure swing adsorption. There is something called a zeolite which is a carbon structure that has an opening that will adsorb nitrogen under pressure, and release it when depressurized.
Air is pumped into the zeolite sieves and the nitrogen is adsorbed resulting in a mix which is ~4.55 parts O2 to 1 part Ar which is roughly 95%/5%.
If you put another type of filter to remove the argon, you could remove it in a similar way
A good overview of oxygen production here actually
http://www.ou.edu/class/che-design/a-design/projects-2007/Oxygen Generator-Presentation.pdf
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