RE: [PSUBS-MAILIST] Co2 removal, without disposables.

[Alec Smyth <Asmyth@changepoint.com>]

Sorry to burst the bubble, but I'm afraid 900 psi is equivalent to a depth
of over 2,000 fsw. At that pressure, you would not be around to enjoy the
nice scrubbed air. 

-Alec

-----Original Message-----
From: Nero Wolfe [mailto:wolfe19@megsinet.net]
Sent: Tuesday, January 23, 2001 1:05 AM
To: personal_submersibles@psubs.org
Subject: [PSUBS-MAILIST] Co2 removal, without disposables.


Well, I was sitting drawing idly in class today, and figured if I had a sub
that could stay down a few days, how would I deal with co2.  I'm into
paintball, and most of the low end guns run off of co2.  Co2 behaves funny
in comparison to most gasses I know of.  Co2 is a liquid at room temprature,
given it's at 800psi.  (dry ice is what you get when you relive the pressure
on a volume of liquid co2)  

What came to mind was, if you compressed cabin air, to say... 900psi, and
gave a small vertical chamber to let gravity filter liquid co2 from other
compressed gasses, you could make a renewable co2 removal system.

>From the work i've done with paintball, you wouldn't need a large volume of
equipment, and heck, you could even run a regenerator off the exhaust gas
from the compressed air chamber, to help reduce energy useage.  The chamber
could be as small as 6"x2."  Just big enough to put a small partition at the
top, and a small enough diameter at the bottom to allow easy draining off of
liquid co2.  Heck, with a diameter that small, you could easily rig up a
float and a solonoid to facilitate the venting off of liquid co2.  

The only quipment this would need to function other than the chamber, is a
compressor, and a condensor.  The condensor is easy.  A small bottle of
water, slowly exchanged with seawater (our infinte heatsink, tee hee hee)
And a coil of tubing inside to cool the air coming from the compressor.  And
then the chamber afterwords to seperate out the liquid from the gas, and out
the other side.

The compressor is a little more difficult.  though, with a 3 stage
compressor, it would still be fairly simple.  Because you can essentially
suck all the co2 out of the atmosphere, and not harm yourself, you can let
it run constantly.  So, for power to turn the compressor you can just run it
off the propulsion motor.  AND you could runa regenerator off the air coming
off the "settling chamber."  Basicly you could run a small compressed air
motor off of it, which will both dampen the hiss/wistle of gas coming off
the settling chamber, and recoup some of the losses from the system.

Again, the side benifit of this, is lack of recouring cost.  at most you'd
need to replace o-rings in the system, and maybe the drive belt :)
depending on design this can be a VERY simple task.  Welp, nuff ranting for
now.

-Nero