O2 Concentrator instead of O2 tank

"Jim Macklin" wrote in message
...
If you don't increase the concentration of oxygen, but are
merely removing N, the partial pressure of the oxygen will
not increase.

Ummm, yes it does. You ARE incresing the concentration of oxygen by
removing the nitrogen and using what is left. Partial pressure is based on the
concentration of a given gas and a higher concentration of oxygen means a higher
partial pressure if all else stays equal.

Oxygen concentrators are nothing new. Only the concept of making them
truly portable is new. My wive needs oxygen for the duration of our frequent
trips to Denver, and I can tell you from experience that either pure oxygen or
oxygen from a concentrator serve equally fine to increase her oxygen sats.
Flying would be no different.

By the way, this concentrator technology is becoming so common that even
tire shops are rapidly getting it, so they can charge you more for putting
nitrogen in your tires rather than ordinary air.


Vaughn

Looking a bit more, I still don't see these units being recommended for
civil aircraft, but the specifications look fairly good. They more
typically require 40 to 60 watts to get 5 liters per minute flow of 80%
to 90% oxygen at several psi. Prices vary from $500 for reconditioned
units to $1000 to $4000 for new ones. Some of them are even designed
to fill high pressure tanks at home, if you prefer to stick with a
tank. If I were a frequent high flyer, I would persue this some more.

tom

This is done in military helicopters--oxygen for the crew and dry nitrogen
for the air space in the fuel tanks. By now, it is almost certainly done in
some other aircraft as well.

I have believed for some that this would be a good primary method to supply
oxigen in light civil aircraft--with "candles" such as the airlines use as
emergency backup.

Try a Google or WebCrawler search with the argument: oxygen + concentrator
(or) oxygen + concentrator + aircraft

Peter

If you evaporate water from a salt+water solution, does the
concentration of salt increase? Sure it does.

Think of nitrogen as the water, and the oxygen as the salt.



Jim Macklin wrote:
If you don't increase the concentration of oxygen, but are
merely removing N, the partial pressure of the oxygen will
not increase.

Pure O2 in a tank, delivered to a mask to displace some of
the ambient air and replace the displaced portion certainly
raises the O2 partial pressure. But an O2 concentrator
doesn't seem to have a pressure function or am I missing
something?



"Vaughn Simon" wrote in
message
news |
| "Bill Denton" wrote in message
| t...
| O2 Concentrators work by removing nitrogen from the
ambient air, leaving the
| oxygen, which comprises 21% of the air.
|
| At altitude, the air still contains 21% oxygen. But
since the air is
| "thinner", it contains less oxygen than does the air at
sea level.
|
| So removing the nitrogen doesn't actually provide any
additional oxygen at
| altitude.
|
| So, would a concentrator even provide any benefits?
|
| Yes, because you are breathing air with a higher
concentration of oxygen,
| wich will result in higher blood oxygen saturation levels.
My wife has used
| one of those battery operated concentrators for commercial
air travel with great
| results. They are a fairly new product, and cost around
5 AMUs.
|
| To solve the power problem, it would be theoretically
possible to build a
| concentrator with a belt-driven compressor as a permanent
installation in a
| aircraft. It would not be cheap, but it would be far
cheaper than
| pressurization. Perhaps some clever engineer could build
a dual vacuum
| pump/compressor to bolt on the same engine pad as your
vacuum pump. With an
| installation like that, you could afford to fly with
oxygen always and enjoy the
| better eyesight and quicker thinking that comes with 100%
blood oxygen
| saturation.
|
| Vaughn
|
|

There certainly won't be any cost advantage unless the system receives a lot
of use.

Peter

Looking a bit more, I still don't see these units being recommended for
civil aircraft, but the specifications look fairly good. They more
typically require 40 to 60 watts to get 5 liters per minute flow of 80%
to 90% oxygen at several psi. Prices vary from $500 for reconditioned
units to $1000 to $4000 for new ones. Some of them are even designed
to fill high pressure tanks at home, if you prefer to stick with a
tank. If I were a frequent high flyer, I would persue this some more.

tom

This is done in military helicopters--oxygen for the crew and dry
nitrogen
for the air space in the fuel tanks. By now, it is almost certainly
done in
some other aircraft as well.

I have believed for some that this would be a good primary method to
supply
oxigen in light civil aircraft--with "candles" such as the airlines use
as
emergency backup.

Try a Google or WebCrawler search with the argument: oxygen +
concentrator
(or) oxygen + concentrator + aircraft

Peter

"Peter Dohm" wrote in message
...
There certainly won't be any cost advantage unless the system receives a
lot
of use.

Peter

If you're an O2 user, think of the convenience. No more having to pick FBO's
and airports based on O2 availability. Also, consider that you'd probably
use the concentrator on many flights in the 6-12k ft region, and will feel
better after those flights than if you had a bottled O2 system and didn't
use it because you were hoarding O2 for when you "really" need it.

"Jim Macklin" wrote in message
...
If you don't increase the concentration of oxygen, but are
merely removing N, the partial pressure of the oxygen will
not increase.

You can't remove N without increasing the concentration of O, unless you
intentionally replace the N with something other than O. So, yes...you're
right that if you don't increase the concentration of O, the partial
pressure of O will stay the same. But you'd have to go to extra trouble to
do that. Simply removing N will necessarily increase the concentration of
O.

Pure O2 in a tank, delivered to a mask to displace some of
the ambient air and replace the displaced portion certainly
raises the O2 partial pressure. But an O2 concentrator
doesn't seem to have a pressure function or am I missing
something?

The cannulas and masks used in general aviation don't "have a pressure
function". They work simply by adding O to the stream of air being
breathed.

If you have a mix of N and O, you can increase the concentration of O either
by adding O or removing N. Conventional oxygen systems work by doing the
former, while the concentrator discussed here does the latter. In either
case, the result is the same.

Pete

There certainly won't be any cost advantage unless the system receives a
lot
of use.

Peter

If you're an O2 user, think of the convenience. No more having to pick
FBO's
and airports based on O2 availability. Also, consider that you'd probably
use the concentrator on many flights in the 6-12k ft region, and will feel
better after those flights than if you had a bottled O2 system and didn't
use it because you were hoarding O2 for when you "really" need it.


I agree.

Peter

Hmm ... if oxygen concentrators are (or will become) sufficiently
efficient and economical, they could offer an alternative to cabin
pressurization, on both GA and commercial aircraft.

The main reason for cabin pressurization is to provide enough oxygen
for crew and passengers without the need for individual oxygen
systems. However, if you can economically enrich the cabin atmosphere
with oxygen using oxygen concentrators, you could keep the cabin
pressure much lower--possibly even at the ambient outside pressure, up
to certain altitudes. This might be a lot less expensive to engineer
and maintain than full pressurization systems. American astronauts
have long used this type of system.

You could also use the nitrogen from the system to fill fuel tanks, to
reduce the risk of fire, evaporation, condensation, etc.

--
Transpose mxsmanic and gmail to reach me by e-mail.

Recently, Larry Dighera posted:

On Sat, 02 Dec 2006 11:42:08 GMT, "Neil Gould"
wrote in
:

At 12v, 100w = 8.3 amps; 400w = 33.2 amps (half those for 24v
systems). That's a lot of juice to draw.

I thought about that too, but IIRC cigar lighters are fused at 10A,
and the pilot alone can operate on oxygen up to 15,000' for thirty
minutes without oxygen for passengers:

As a rule of thumb, the safety margin in many electrical circuits is
around 66% (2/3) of the fuse/breaker rating. A cigar lighter using the
heating element draws a certain amount of current for a relatively short
time. Putting a 80% full-time load on that circuit would not be wise,
IMO. I haven't run accross any 50 amp breakers on the panels in the GA
plane that I fly.

Another consideration, your alternator will have to carry that load *plus*
everything else in the plane and still supply regenerative power to the
battery to be practical and reliable. So, if someone wants to go this
route, several aspects of the plane's electrical system might need some
attention.

Neil

But we aren't discussing the concentration of O2...

What we are providing is a constant stream of pure O2. It may come from a
tank, or it may come from a concentrator.

Think of a Mason jar...

At sea level, we take an open jar and put the lid on it. The jar now
contains "X" amount of air, of which 21% is oxygen.

We take another open jar to 20,000 feet and put the lid on it. The
concentration of oxygen remains at 21%, but because the air is thinner, the
amount of air in the jar is LESS than the "X" amount in the "sea level" jar.

If we extract the nitrogen from both jars, the "sea level" jar will contain
more oxygen than the "20,000 feet" jar.

You would not net any additional oxygen from the concentrator...







"Peter Duniho" wrote in message
...
"Jim Macklin" wrote in message
...
If you don't increase the concentration of oxygen, but are
merely removing N, the partial pressure of the oxygen will
not increase.

You can't remove N without increasing the concentration of O, unless you
intentionally replace the N with something other than O. So, yes...you're
right that if you don't increase the concentration of O, the partial
pressure of O will stay the same. But you'd have to go to extra trouble
to
do that. Simply removing N will necessarily increase the concentration of
O.

Pure O2 in a tank, delivered to a mask to displace some of
the ambient air and replace the displaced portion certainly
raises the O2 partial pressure. But an O2 concentrator
doesn't seem to have a pressure function or am I missing
something?

The cannulas and masks used in general aviation don't "have a pressure
function". They work simply by adding O to the stream of air being
breathed.

If you have a mix of N and O, you can increase the concentration of O
either
by adding O or removing N. Conventional oxygen systems work by doing the
former, while the concentrator discussed here does the latter. In either
case, the result is the same.

Pete