Oxygen concentrators

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Vigilant1

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At >>some<< point, if the need is great enough and money is available, surely LOX starts to make sense. Simple ( in theory) and not too heavy if the duration is not great.

And re the discussion about O2 augmentation for the engine:. Of course, that's what the street racers do with nitrous oxide. It's not practical to carry enough to run it for a long time, but 30 seconds is do-able. I see folks posting here all the time about the supposed practicality of making double the stock HP with RPMs, tuning, magic coatings, high CRs, etc. Well, if that's true, just fit a nitrous kit and use it whenever you need it.
 
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blane.c

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Well you know when these Briggs things start being run-O-the-mill some almost human type is going to take em' up were you can barely breathe. Someone should have something figured out first.
 

blane.c

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Honestly methanol won't give you any more power it will give you less. Look at the BTU's.

http://www.smokemup.com/tech/fuels.php

Ok it'll burn at more btu's (10%) but at over twice the amount of fuel to do it. Methanol also weighs 10% more than gas so you are taking a double hit. Basically you will go half as far on methanol for the same tank volume as gas. And of course it is a pain in the * to tune for.
 
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Aesquire

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Booze for fuel permits higher compression ratios or more boost. Methanol, isopropyl, ethanol, it's not that it has it's own oxygen, it's detonation resistance. Many modern hot rodders use E85 in their supercharged or high compression engines, cheaper than 100+ octane race fuel.

My father uses an Oxygen concentrator. A large suitcase 115 volt home unit and a battery powered portable. The portable is quite pricey, and has the same approx. time limits as a small portable bottle. I'll check to see if a car's 12 volt system can run it indefinitely. I think so. But can't swear to it.

https://www.inogen.com/support/faqs/
 

Aesquire

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As to using one to boost an engine? Nope. Not enough flow and too expensive in energy use. Gaseous O2 bottle weighs far too much. LOX is better, but still stupid.

Nitrous is stored as a liquid, and was used in WW2 German aircraft, but only good for a few minutes... Which since no one here needs to catch or escape enemy fighters... It IS useful for take off power. And reasonable in cost for short periods.
 

AdrianS

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...
Nitrous is stored as a liquid, and was used in WW2 German aircraft, but only good for a few minutes... Which since no one here needs to catch or escape enemy fighters... It IS useful for take off power. And reasonable in cost for short periods.
Wives, ex-wives, debt collectors, reporters, bail bondsmen... still plenty of reasons to desire a fast take-off.
 

Aesquire

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I checked, and t he portable concentrators will run on 12 volt auto power, but are only rated to about 15,000 feet before the system is considered not good enough for supplemental medical use. Check the specs for the specific model you're interested in.
 

pictsidhe

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I checked, and t he portable concentrators will run on 12 volt auto power, but are only rated to about 15,000 feet before the system is considered not good enough for supplemental medical use. Check the specs for the specific model you're interested in.
If you hooked one up to a rebreather, they would go a lot higher. Have a constant air flow through the rebreather, run the scrubbed exhaust and some make up air through the concentrator.
 

blane.c

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I checked, and t he portable concentrators will run on 12 volt auto power, but are only rated to about 15,000 feet before the system is considered not good enough for supplemental medical use. Check the specs for the specific model you're interested in.
15,000ft is more than enough. It is not to replace supplemental oxygen requirements and required equipment, just to make flying easier between say 8,000ft and 12,000ft. A good many people start sucking on oxygen at 10,000ft if not sooner. If you want to cruise at medium altitude it just might be "nice" and since oxygen is not required at these altitudes it isn't a regulatory issue.
 

rv7charlie

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Ethanol's issues are relatively easy to handle; lots of guys are running E-10 & E-15 in Lycs on a regular basis. Methanol... not so much. Most issues with E-gas are related to making sure that the 'soft' stuff in the fuel system is compatible with ethanol, and not letting the fuel get old before use. Corrosion with ethanol is mostly old garage tales, but it's a very real issue with methanol.
https://www.google.com/search?q=will+methanol+corrode+aluminum&oq=will+methanol+corrode+aluminum&aqs=chrome..69i57j0.8173j0j7&sourceid=chrome&ie=UTF-8

Nitros: This guy ran it for years, but I haven't heard anything from him in a long time. His web site is dead now; I had to pull an archive from the Wayback Machine dated about 15 years ago.
https://web.archive.org/web/20040202172859/http://homepage.mac.com/rotarycoot/
He had a 'special need'. But that's a lot of extra hardware weight to carry around all the time, if it'll only get used a couple of times a year.

Charlie
 

Aesquire

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A rebreather? So, a CO2 scrubber, basically a can full of chemicals, and an Oxygen tank! PLUS an Oxygen concentrator? That's over the weight and cost budget for a normal Oxygen system. Overkill meets not good enough.

Modern Scuba rebreathers are very pricy! Computers that are nigh 100% reliable and waterproof to boot aren't cheap. ditto heavy duty electronic mixing valves designed for multiple atmospheres of water pressure. The old WW2/Korean War surplus rigs are a known quantity. Better than having grenades tossed in the water you are in while you swim near the enemy. I've used one, in company with a buddy with an extra mouthpiece on his standard Scuba gear, in case it failed. An interesting history lesson but there's a reason they are most commonly used by military divers in hostile waters to avoid tell take bubbles. Heavy, dangerous, and expensive.
 

pictsidhe

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A rebreather? So, a CO2 scrubber, basically a can full of chemicals, and an Oxygen tank! PLUS an Oxygen concentrator? That's over the weight and cost budget for a normal Oxygen system. Overkill meets not good enough.

Modern Scuba rebreathers are very pricy! Computers that are nigh 100% reliable and waterproof to boot aren't cheap. ditto heavy duty electronic mixing valves designed for multiple atmospheres of water pressure. The old WW2/Korean War surplus rigs are a known quantity. Better than having grenades tossed in the water you are in while you swim near the enemy. I've used one, in company with a buddy with an extra mouthpiece on his standard Scuba gear, in case it failed. An interesting history lesson but there's a reason they are most commonly used by military divers in hostile waters to avoid tell take bubbles. Heavy, dangerous, and expensive.
You don't need a military grade rebreather to save a lot of oxygen. With a concentrator, you won't need an oxygen tank. There are simpler, lighter and more reliable ways to build rebreathers that aren't 100% rebreathe. Yes, you'll still need a scrubber and perhaps a fan or two. the scrubbers are consumables and easily available. A concentrator is appealling to those who have trouble obtaining or paying for oxygen. Or on extremely long flights when tanks start to get heavy.
 

Flow

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Yes. I've spoken to the folks who sell the portable ones at OSH a few times. Can't justify the cost (yet).

Small battery or 12V powered concentrators that weigh about 3 - 10 lb. exist, but they're a few thousand $$$. See:


There's a Long-EZ builder in Australia who's planning a round the world trip where some legs would be far longer than an O2 bottle would last, and has experimented with a concentrator in a friend's Mooney (IIRC) I BELIEVE that he told me that they went up to 18K ft. and were still able to keep their SpO2 levels above 90% breathing the O2 from the concentrator cannula. See:


So, if you have a need that O2 bottles don't fill, and you have the $$$ for a small concentrator, they can work well.
Very informative Marc!

It looks like he was using an Inogen One G2 weighing 12lbs with no 12V charging capability with the following flow rates as listed in the technical manual:

1588367763516.png

It looks like the the Inogen One G5 comes out top POC Comparison Oct 30 2019 in the current crop of Portable Oxygen Concentrators.

1588368867052.png

The G5 weighs in at 4.7lbs with 12V charging capability and conforms to all applicable FAA requirements for POC use on board an aircraft with the following flow rates as listed in the technical manual:

1588368237519.png

Note that POCs deliver ~90% O2 rather than 99.9% from a tank and that the delivery charges go down as your breathing rate goes up. Which is likely why Dave mentioned he got better results with proper breathing technique in the test in the Mooney to FL180

At $2400 new and around $1000 for lesser units on ebay in today's money with the bed sieves running around $150 and only needing to be replaced every 12-18 months (with regular home use) is not too bad IMO considering what I paid for my O2D2 CFFC 48 Mountain High system. I think POCs are the future for sure. Not having a bottle of compressed O2 on board in a crash is a second order bonus as well.
 
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Flow

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Good spot, did you find anything battery powered or 12V chargeable?

I have been looking at the refill stations coming down in price as well. They produce around ~93% pure O2.
DeVilbiss iFill Personal Oxygen Tank Refill Station - 535D ~$2200 today.
 
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