Re: [PSUBS-MAILIST] CO2 Scrubbers

["D. Blake" <dblake@bright.net>]

Hello Suds:
Thank you!  This is a great post, and very informative.  Looks like you have
done your homework.
Interesting you should mention "infectious".  Seems like this is a very
important issue these days (especially in my line of work).  I may be giving
away my years, but it is unfortunate that everything has become so
complicated.  Jeez, I remember not so long ago we (friends...uh...everybody)
use to pass around a bottle and virtually everything else with no worries.
Nowadays it seems like you got to wash your hands every five minutes or else
catch something.
Still, a very good post.
Thanks,
Big Dave
-----Original Message-----
From: Paul Suds <paul_suds@hotmail.com>
To: personal_submersibles@psubs.org <personal_submersibles@psubs.org>
Date: Friday, August 04, 2000 6:10 PM
Subject: Re: [PSUBS-MAILIST] CO2 Scrubbers


>While doing my research on scrubbers, I came across this from a website and
>saved it. I used to do some training (volunteer) of firefighters, who used
>Bio-Marine Bio-Packs. I don't know whether they are still in business. One
>day while preparing for the class, I read the tech manual, and tore a unit
>down. I noticed that the absorbent material was called Sodasorb. I believe
>if you type "rebreathers" into your search engine, you will find more than
>enough information for a good design. As a long time scuba diver (since
>1974, double hose regulator days), I always keep in the back of my head a
>term that came out during my initial training "hypercapnia." Remember, It's
>not just the oxygen that you have to contend with, in addition to a good
>oxygen sensor, you better have a very good and sensitive CO2 sensor as well
>(maybe two of each). Usually, the CO2 won't build up very fast in a sub,
but
>that depends on free air space, metabolism, and time under water. Unless
you
>are staying down for a long time, it probably will not be a problem. For my
>sub design, I have a lot less air space, and calculated a little over 11.8
>hrs for it to get to .5% at 1 atm (.005 ATA). This is based on 60 ft3. With
>a safety margin of 4 on this, I would not stay down more than 3 hours
>without a good scrubber.  Here's the article. For you rebreather types,
>please correct me if I am wrong. And please, always do your own research.
>Get advise from other people, but never bet your life on it unless you have
>thoroughly researched it first and have talked to the experts (not me :).
>Oh, I think they are confused between partial pressures and percents. They
>tend to use them interchangably. They use .005% instead of .005 ATA
(partial
>pressure decimal units).
>.005 ATA would be .5% at 1 atmosphere.
>Suds