You could either have it run continuously filling a buffer chamber you breathe from via a regulator or simply compress the thin available air into a tank and tap into it as necessary.
Route the exhaust through some kind of heat exchanger to make the thickened air you breathe warmer as well. You could then route it through your boots before blowing it out.
I would think the additional weight of the fuel would be more than offset by the fact that you'd be breathing warm sea level pressure air all the way up.-- doctorremulac3, Apr 30 2010 Gamow Bag http://www.chinookm...,-Government-Model- [MisterQED, Apr 30 2010] Atmospheric pressure model http://en.wikipedia...tmospheric_pressure [MisterQED, Apr 30 2010] Portable oxygen concentrators http://www.oxygenconcentrators.org/ [arvin, Apr 30 2010] What my search for "air mask" came up with on youtube http://www.youtube....watch?v=nnaoONhxMfIIgnore the dumb latex outfit, check out the mask, tank and regulator. (Viewer warning: girl in latex suit. Fully clothed but may be suggestive to some pervo types) [doctorremulac3, May 01 2010] Mr Creosote blows up http://www.youtube....watch?v=rXH_12QWWg8 [doctorremulac3, May 05 2010] Wiki on partial pressures http://en.wikipedia...ki/Partial_pressureRequired reading [Custardguts, May 05 2010] Happy food http://www.nbc.com/...kin-chicken/229063/ [doctorremulac3, May 06 2010] Well you'd calculate how much fuel you'd need for the trip obviously.-- doctorremulac3, Apr 30 2010 Don't you want oxygen-enriched air up there, not compressed air?
I mean you take a lungful of air from the tank of compressed air. Your lungs expand to equalise with the outside pressure. Your lungs still struggle to extract oxygen because the partial pressure of oxygen is so much lower than at sea level. You carried up the heavy engine and tank for nothing.
Now if this thing had some kind of osmotic membrane oxygen-concentrating thingy on it I'd be more convinced.
Next issue: getting your little engine to run at altitude.... Maybe it needs an oxygen bottle.....
Lastly, calculating how much fuel you need doesn't rank very high on my list of "things I'd trust to save my life when SHTF".-- Custardguts, Apr 30 2010 Well, I don't think the engine would weigh much, a couple of pounds at most. I would think even a leaf blower sized motor would be overkill.
I know piston engine aircraft can get to very high altitudes using superchargers and they breathe air to well over 30,000 feet which is higher than Everest. That's using oxygen extracted from the atmosphere obviously, not carried onboard in bottles. Funny line though.
Not sure I get what you're saying about the lungs struggling to extract oxygen, I would think lungs expanding with air is a good thing since that's the whole idea.
Are you saying that the percentage of oxygen at higher altitudes is less because the mixture changes the higher up you go? If so that would certainly be a problem but I couldn't find anything about that doing a quick web search, maybe you're right.
At any rate, it seems to me that even if you ran this thing only part of the trip, maybe 10 minutes every hour while you rest and warm up, you could get some potentially life saving benefits.
I wouldn't be totally suprised if there were some reason this wouldn't work though, mainly because I would think somebody would have thought of it already.
If there's a fatal flaw, let me know. That's what this forum's all about.-- doctorremulac3, Apr 30 2010 // If there's a fatal flaw, let me know. That's what this forum's all about.// Well, I would say you are missing a crucial piece of the puzzle, a space suit or at least a partial pressure suit. Superchargers work on ICE but if you pump the air in to a person, what will pump the air out? Your lungs can't work against any significant differential pressure, it would just blow you up like a balloon. If you add in a space suit/partial pressure suit you'd have a hyperbaric suit. Climbers commonly carry hyperbaric chambers at high altitudes called Gamow bags (link). So the rough idea is baked.
Making that into a suit isn't impossible, but it is hard to keep it flexible.
[CG] I don't think there is significant oxygen depletion by percentage at climbable attitudes, just low pressure so low oxygen.-- MisterQED, Apr 30 2010 Oh, I get it, I didn't make clear that it goes into a buffer chamber of some sort before you breath it. You don't hook a high pressure air hose up to your mouth and have your eyes bug out of your head. LOL. I should have said "run continuously or SIMPLY compress the thin air into a tank"
Yea, a high pressure hose in your mouth wouldn't work too well.
Thanks for the link MQ, My thing would be a little along the same line of but tapping into a high pressure chamber with a regulator you breath from just like on a scuba suit. Instead of the foot operated pump you've got a little lawnmower engine doing the work compressing the air in the buffer chamber or tank.-- doctorremulac3, Apr 30 2010 //Oh, I get it, I didn't make clear that it goes into a buffer chamber of some sort before you breath it// Sorry, but that doesn't matter, unless you are raising the partial pressure of the oxygen while decreasing the partial pressure of one of the other components, which you have not mentioned, you need to raise the total pressure of the air that the climber is breathing. That means raising the air pressure in the climbers lungs over the ambient pressure, thus inflating the climber. ICE engines don't have this problem because they are not built like balloons, but we are. If you expose your lungs to higher than ambient pressure, you better apply a reasonably equivalent pressure to the outside of the lungs if you want to continue breathing.
SCUBA systems work because they apply pressure equivalent to the ambient pressure the diver is experiencing. If it provides less, the divers lungs will not expand, if it provides more then the excess pressure will just bubble away leaving just enough to balance pressure as your lips will not hold it in.
Climbers experience lower than normal pressures instead of the excess pressures that divers experience, but the same rules apply. Any excess pressure over ambient will have to be released. If you enclose enough of the climber in a suit you can alter the effective pressure that the climber experiences which will allow you to increase the air pressure feeding to their lungs and thus raise the quantity of oxygen as you raise the pressure of the air the person breathes.
Since climbers only go so high, and you only need to keep their experienced pressure to <8000ft for airplane like comfort or at least <25000ft to stay out of the death zone, you will need to have a helmet with a pressurized inlet connected to a bladder that is strapped around the wear's chest to provide an artificially high ambient pressure inside and outside the lung wall.
The link shows you probably need about 3psi (boost from .3atm to .5atm) differential for someone on Everest to experience passable oxygen levels. Multiply that by the area of a persons chest, say 144 sq.in., you will DEFINITELY need a chest bladder or that ~450lbs of force will blow you up like a balloon.-- MisterQED, Apr 30 2010 I don't think you can breathe air that is significantly higher pressure than the atmosphere outside - it would probably cause decompression sickness. Mountaineers breathe pure oxygen, but at more or less the same pressure as it is outside.
The idea could work if you could attach an air separator to increase the concentration of oxygen, which could be then powered with a portable IC engine.
Edit: seems to be baked, at least as battery- powered portable oxygen concentrators for medical applications. See the link.-- arvin, Apr 30 2010 //I don't think you can breathe air that is significantly higher pressure than the atmosphere outside// Sure you can, astronauts do it all the time. Yes, one way is to raise the specific oxygen level, but the other is to create an artificial high pressure area for your lungs.-- MisterQED, Apr 30 2010 So what happens if this gal takes this contraption up a mountain? (see link) This is my idea only it's got a gas engine refilling the tank.
Plus mine doesn't include the latex bondage suit.-- doctorremulac3, May 01 2010 It does have the high heels option though.-- doctorremulac3, May 01 2010 //So what happens if this gal takes this contraption up a mountain?// Gas masks weren't designed to hold positive pressure, so if pressure exceeds ambient, it will burp out the sides. So per my Atmospheric pressure link, say you are above 25000 feet in the death zone, the air pressure is 1/3atm and your brain cells are dying. You run your gas powered pump and it pressurizes the atmosphere from 1/3atm to 1/2atm, as soon as you connect that feed at 1/2atm to your mouth the higher pressure air will fill you like a balloon as there is only 1/3atm pressing on your stomach and now >1/3atm inside your lungs. Once your lungs completely inflate the air pressure in your lungs will start to rise and one of two things will happen, the mask will release the over pressure or the mask will contain the over pressure and you will start to stretch your lungs possibly all the way to the full 1/6atm differential. Once there is any significant pressure differential you will not have the strength to exhale, the CO2 will pool in your lungs and you will not like it. If you can get a good enough seal and can get the air in your lungs to 1/2atm, you will probably burst, though I have no proof of that.
As a point of comparison, I have a Zodiac and it is designed to be inflated to 1/6atm, at which point it is firm and deforms only slightly when I sit on a tube. So expect your lungs to act much the same, if they can hold the pressure.-- MisterQED, May 02 2010 Obviously, the scheme could be arranged to release pressure when you want to breathe out. This could be arranged by monitoring the back perssure, which could be used to stop the filling lung process, and then allow bleed off until bleed off finishes.
At best, it would be an "assisted breathing" system, where less energy would be required to simply breathe. If the pressure is too much above ambient, then I think the mountain would be littered with Alien-type mountaineers, with exploded rib cages*.
* exaggeration, of course.-- Ling, May 02 2010 [MisterQED]: //Gas masks weren't designed to hold positive pressure, so if pressure exceeds ambient, it will burp out the sides.// There exist gas masks designed to hold positive pressure without burping: they're used in the treatment of sleep apnea.
[Ling]//release pressure when you want to breathe out// this is how modern versions of sleep-apnea systems and endotrachial ventilators do it.
//exploded rib cages// Ruptured alveoli, actually. About 40 cm H_2O is (so I gather) the point at which lung damage ("barotrauma") begins, with endotrachial positive pressure ventilation. So, less than 0.04 atmospheres maximum pressure differential between ambient and mask. That's less than 4% increase in oxygenation available with this technique. Assuming I haven't messed up the arithmetic somewhere.
//less energy would be required to simply breath// Work of breathing is negligable compared to the work of mountain climbing. Maybe this would be useful for pulmonary edema cases, though.-- mouseposture, May 02 2010 [doc], a space suit or partial pressure suit is like being inside a body-shaped balloon. Inside the balloon there's a pocket of atmosphere-pressure air that you are breathing. Scuba is different, as the diver is being compressed by the water, and the air he is breathing is being compressed as well. When you take a breath at 20 feet under water, you're breathing 3 times as much air as at the surface (if I remember correctly, it's 1 atm/10 feet). That's why you have to exhale as you ascend, or the air in your lungs will expand, and you'll pop.
Obviously, air tries to become whatever ambient pressure is around it. Like [MrQED] is explaining, your lungs are breathing ambient pressure air, and when the higher pressure air is introduced to them, it tries to become ambient pressure, and inflate you, unless you breake the seal to exhale. Something's got to take the pressure, like the walls of a balloon you're in. In that case, the balloon is containing the pressure, and you're just existing inside a high-pressure cocoon.-- CaptainClapper, May 02 2010 //Gas masks weren't designed to hold positive pressure, so if pressure exceeds ambient, it will burp out the sides. ... as soon as you connect that feed at 1/2atm to your mouth the higher pressure air will fill you like a balloon//
If the air is spilling out of the side of the mask how does it blow you up like a balloon? You've just got a rush of high pressure air blowing in your face that you can breathe from before it spills out the sides of your mask.
Like drinking from a water hose, you don't stick it in your mouth but that doesn't mean you can't drink from the stream.
There's no need for a seal here, you can breathe from a stream of gas being blown freely through the ambient atmosphere especially if it's loosely contained in a mask before being leaked out. There's a high pressure air flow from the tube to the mask outlet that can be tapped into. Like the scene in Platoon where they're smoking weed by blowing it through a shotgun, they didn't have to put the thing in their mouth to get stoned.
Only example I could think of.
Whether or not you'd get enough additional oxygen out of it to be worth it, not sure. But blowing up like an Mr Creosote (see link) wouldn't be a problem.-- doctorremulac3, May 05 2010 //Like drinking from a water hose, you don't stick it in your mouth but that doesn't mean you can't drink from the stream.//
True, true - but that doesn't mean your stomach gets pressurised to the 40-ish PSI that the municipal water supply is regulated at, either.
This is becoming a fairly belaboured point, I'll see if I can summarise. The percentage oxygen in the air at altitude isn't less, however at low atmospheric pressure, your lungs can't do anything with the oxygen in the air (because 21% oxygen at 0.5 Atm is to your lungs just like 10.5% oxygen at 1 Atm - get it? The oxygen solubility and permeability is lower becasue the partial pressure is lower).
The thing about the mask seal is a red herring. Regardless of whether the mask seals on you face or not, your lungs won't hold an internal pressure of 1 Atm whilst outside your ribcage it's 0.5 Atm, or whatever. The gas pressure will expand your chest (possibly to the detriment of your health) until you equalise.
So - you don't have trouble filling your lungs at atmosphere. The biochemistry of your lungs and the way gasses behave depends on the phenomenon of partial pressure. Which means at altitude, you need a higher concentration of oxygen in the air you're breathing, or you need to enclose yourself in a bubble of higher pressure air. Or maybe train for months to survive at lower oxygen partial pressures...
Why not use the gas engine to power an oxygen concentrator instead?-- Custardguts, May 05 2010 I gather it's not hard to get a small engine to run at lower atmospheric pressure, although I'm not as familiar as some...
Maybe a very high compression head could be used (where the engine won't work without pinging below a certain altitude) - or maybe use variable compression, or use a small turbine (less sensetive), or use a turbo-or-super-charged engine.
Probably pretty expensive, though.-- Custardguts, May 05 2010 //The gas pressure will expand your chest (possibly to the detriment of your health) until you equalise.//
If there's a seal, but if it's just air blowing in your face there wouldn't be any pressure to blow your lungs up. Without a seal, there's no back pressure, I think it's called "gauge pressure" in plumbing to stick with the hose analogy. When you put the hose in your mouth and seal it with your lips, you're going to direct all that pressure into your mouth and it'll blow you up, but if you hold the hose an inch away from your face, the back pressure is dissipated and you're simply drinking from a stream of water traveling as a result of velocity only. Same thing happens with air.
And the pressure of the air coming out of a compressed air tank doesn't dissipate immediately, it needs to travel from it's confined space to the space it wants to equalize, the lower pressure ambient, and that takes some measure of time. So why not have it blow into your face and breathe it on it's way? The cavities in your lungs are at the same atmospheric pressure as their surroundings except slightly less when they inhale, so that compressed air would rather go into your lungs than the outside when you breathe in. That freed stream of air will travel to the lowest pressure area, and that's your lungs when you inhale.
I'll put it another way. You've got a tank of air on a mountain top. You open it and stick it in your face so it feels like you're in a strong wind, but nothing is pumping up your lungs. Can you breath without your lungs blowing up? Sure. Is it worth the trouble? That's the question.
As far as the oxygen concentrator, that's a good question. Why don't they do that?
Some kind of gas powered concentration device of some sort seems like such an obvious way to alleviate one of the biggest problems of mountain climbing, I really don't see why it hasn't been done. Plus the bonus of that waste heat from the engine being able to warm your air before you breathe it.
Put it this way, till somebody comes up with one of these, I'm staying off Everest.
In fact I'll stay off until they put in a heated elevator leading to a heated, pressurized restaurant on top.-- doctorremulac3, May 05 2010 Fairly simple solution. The storage tank is a vest with a semi-rigid outer shell (easy enough to make one that will handle 15 PSI without inflating, but still be flexible enough to move) and flexible inner shell. As it inflates to pressure, the inner shell provides back pressure against the abdominal cavity, limiting expansion. An extension of the tank to cover ears and nose may be neccesary to maintain pressure on all internal spaces.
However, I am less convinced that this is a massive problem. The risk in explosive decompression is the rapid change in pressure. It seems to me that this would produce a repeated, gradual change in pressure (with proper valving) that might not have the same effects. The human torso can support most of 1atm differential between internal and external pressure anyway.-- MechE, May 05 2010 I worked up an idea slightly like this many years ago, but never built it. The design was simply a small axial turbocharger with attached mouthpiece. The user blew out strongly to spin up the turbine, then inhaled air compressed by the the compressor. I was working out ways to store momentum or air, but gave it up when I realized that compressed air in the lungs and ears was a bad thing.
In all the discussions above, some folks seem to ignore the dangers of lung inflation. Others seem to think that compressing the air, then letting it expand again through a regulator before inhaling somehow takes all the danger out--it also takes all the compression out, and is a complete waste of time. If the air isn't still compressed, it isn't doing anything toward bringing in more oxygen. If it is still compressed, it will inflate and kill the user.
Try going up or down hill without popping your ears. Hurts, don't it?
Now, try to imagine any air-breathing apparatus or use that does NOT take extreme precautions to avoid inflating the user.
Then, try to name any air-breathing apparatus or use that does inflate the user even the tiniest bit.
Breathing air at over atmospheric pressure is never done. That part of this idea is bad, I say, and the idea that running it through a regulator will make it all okay isn't a solution. Regulating the compressed air down to a safe level of pressure means taking all the pressure out of it entirely.
Powering a compressor with a gasoline engine is a whole 'nother matter. Weight of fuel, weight of engine and need for a turbocharger at high altitude are all big problems.
Oxygen bottles have few moving parts and do not overpressure the user. That's why climbers use them, and build them as light as possible.-- baconbrain, May 05 2010 Perhaps an electrically powered oxygen concentrator. To save weight, use a hydrogen fuel cell instead of batteries. The oxygen for the fuel cell could come from air that's been exhaled by the user -- this also keeps the fuel cell from freezing.-- goldbb, May 05 2010 //Oxygen bottles have few moving parts and do not overpressure the user.//
Why would compressed air overpressure the user any more than compressed oxygen when they're both at the same pressure? Compressed air is just the same thing with 80% nitrogen. Not as effective, but it doesn't blow you up just because it has nitrogen in it.
By the way, apparently compressed air has been used in mountain climbing on an early Everest expedition, it just makes a lot more sense to carry oxygen. Unless possibly if you compress it yourself with a small gas engine.
Maybe.
So, like I said, I'm not sure if you could get enough oxygen to make it worth your while but the assertions that you'd blow up breathing air any more than you would breathing oxygen are in error.-- doctorremulac3, May 05 2010 "Compressed" oxygen is not supplied to the lungs at high pressure. It's stored compressed, and allowed to expand before breathing. It works by increasing FiO2.
Of course, you *could* allow compressed air to expand before breathing, but the result would be -- exactly the same as breathing ordinary air.
The only way compressed air could do any good is if it's breathed at the elevated pressure -- that would increase PO2, without increasing FiO2.
Unfortunately, positive pressure ventilation is a very well- studied area of physiology. We know how much of it the lungs can tolerate without damage, and it's about 40 cm H2O. That's H2O, not Hg, got it? So you can increase PO2 by -- maximally -- 4% with this method, while bottled oxygen increases it by over 400%.
I'm becoming frustrated. One of us is overlooking something. If it's me, please point out my error.-- mouseposture, May 05 2010 //The only way compressed air could do any good is if it's breathed at the elevated pressure//
Right, but it's at some level of elevated pressure in the time between being under containment and leaving the tank and equalizing with the atmosphere. It's fluid in that conversion, can't you tap into it before it's dissipated? Yea, you wouldn't catch all of it but you'd be breathing from a high pressure air stream, at least higher pressure than the air around you.
At least we're beyond the lungs blowing up thing.
I'm certainly at fault for not making it clear from the beginning that I'm not suggesting you stick a high pressure air hose in your mouth any more than you'd try to suck on a wide open fire hose.
But I am suggesting you take a high pressure air hose, aim it towards your mouth and breathe from the high pressure stream before it equalizes with the air around it because that equalization doesn't happen immediately. There is a column of high pressure air moving out of that tube. It isn't high pressure for long, a fraction of a second, but since it's a continuous flow it is a high pressure chunk of air you could potentially breathe from.
Maybe.-- doctorremulac3, May 05 2010 //At least we're beyond the lungs blowing up thing// Maybe, but we're not past the barotrauma thing.
You *are* proposing to stick a high pressure hose in your mouth. A *leaky* hose, so the pressure drops before it reaches your lungs, but doesn't drop all the way to ambient. If it drops too much, it does no good. If it drops not-enough, it damages your lungs. The therapeutic window is extremely narrow (40 cm H2O), and, for some reason, to stay in that window, instead of a pressure regulator, you've chosen to hold the hose a few inches away from your mouth, and try to get it right by guess and by golly.
And, supposing you get it exactly right, we know what the theoretical maximum performance is: two orders of magnitude inferior to the conventional approach.
But not zero. So, if you find yourself stranded halfway up Everest, and all your oxygen's fallen down a crevasse, but you still have the gasoline-powered air compressor you brought along to inflate your air mattress, and you're trying to stay conscious a few minutes longer so you can signal the rescue party then yes this is a good idea.
Edit: which, if you subtract out the snark, means "You're right."-- mouseposture, May 06 2010 Fair enough.
Now let's have a sandwich made with dolphin safe tuna and all be friends.-- doctorremulac3, May 06 2010 Or tuna safe dolphin sandwiches. Either one's good.-- doctorremulac3, May 06 2010 "Friendly Dolphin Tuna" is my favourite brand.-- Custardguts, May 06 2010 I'm partial to any meat product that shows the animal that's been processed really happy about the situation on it's advertising. (see link)-- doctorremulac3, May 06 2010 why not just bring up a battery and use it to for osmosis to crack water. Pure h20 is the result-- metarinka, May 06 2010 random, halfbakery