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Re: [PSUBS-MAILIST] life support method?
Steve:
At about 550 BTUs per occupant there is probably little need for a heater
especially in the confined spaces of a psub where only a few hours is spent
exploring the subsurface before a welcome break. I say this as a result of
what I have read from the experienced members of our discussion group.
I would say that navigating a psub would be not unlike driving a sports car,
or crotch-rocket motorcycle. Intense with a little paranoia handling
controls, looking at gauges, looking forward, side-to-side, and forward
again. At the same time keeping track of depth, air use, and power
available. In other words, very busy, and all the while wondering if the
thing is going to implode on you. How long do you expect keeping this up
without a break?
Vance and maybe a few others are veteran psub pilots, but no doubt used to
piloting subs with proven designs and track records of safety. I doubt thay
would enjoy the prospects of trying-out an amatuer built craft for more than
a little while and at shallow depth before taking a break.
A while back Nemo (Pat) informed me that his ass got sore, or he found
himself having to take a pause for the cause after a short time of covorting
with the fishies and so had to take a break before his vision turned a shade
of yellow (literary license?).
Still, I guess the point I'am trying to get across--from what I
understand--is that operating a psub is not an all-day exercise unless you
include transporting, preparation, launching, diving, retrieval, and washing
down the craft along with everything else imaginable. The amount of time
actually in the water operating the craft is only a few hours at a time.
Maybe I'm under the wrong impression, so correct me if I'am wrong guys.
TTYL,
Big Dave
-----Original Message-----
From: S W <stephenwhite20@yahoo.com>
To: personal_submersibles@psubs.org <personal_submersibles@psubs.org>
Date: Friday, August 04, 2000 8:49 PM
Subject: Re: [PSUBS-MAILIST] life support method?
>Im not sure how much the air within the submarine is
>going to cool since (given we are talking about a
>small PSUB) there is a human within it who is
>constantly giving off body heat and breathing out
>warm, moist air. I don't know for sure, but I would
>guess that the pressure differences attributed to the
>cooling of the air are probably negligable. The
>pressure would have to REALLY drop to cause enough O2
>to be released to be toxic. Another reason why a good
>O2 and CO2 measuring system is important. The idea is
>sound I think. Just curious though,has anyone use or
>contemplate a small, electric onboard heater with a
>little thermastat?
>
>--- Greg Teiber <wolfe19@megsinet.net> wrote:
>> but there is a problem, as the hull cools so will
>> the air, and the air will shrink.. and then you'll
>> end up with excessively high 02..... you'd need
>> somethign to compensate for air temprature
>> changes... so that throws this idea out the
>> window.... unless you want to setup a computer to
>> add n2 to compensate for temprature.
>>
>> *********** REPLY SEPARATOR ***********
>>
>> On 8/4/00 at 9:54 AM Alan D. Secor wrote:
>>
>> >You are right, I just didn't follow though with my
>> explanation...the
>> >bottom line is your body uses O2 and expels
>> CO2...if the CO2 is removed
>> >and the O2 isn't replaced, the net result is a
>> reduction of cabin
>> >pressure.
>> >
>> >Al
>> >
>> >>
>> >>> 2.) If no supplemental O2 were added, the cabin
>> >>> pressure would gradually
>> >>> decrease due to the O2 in the air being
>> metabolized
>> >>> by your body. You
>> >>> are correct in assuming that if O2 were released
>> >>> into the cabin at the
>> >>> rate our body metabolized it, the system would
>> >>> remain fairly balanced.
>> >>
>> >>Actually,
>> >>
>> >>The decrease in pressure in the cabin is NOT
>> caused by
>> >>the "metabolism" of 02 by the body, but rather by
>> the
>> >>conversion of the CO2 to a non-gasous state in the
>> >>form of a chemical compound formed between the
>> >>absorbant and the CO2 (hence the heat/H20
>> emitted).
>> >>Respiration requires 02, but yields as a product
>> CO2,
>> >>which results in no net change in air pressure. It
>> is
>> >>the scrubber which is decreasing the air pressure,
>> not
>> >>the person.
>> >>
>> >>FOR INSTANCE: (Boring Biology stuff for most)
>> >>If you lock a person such as yourself in an
>> airtight
>> >>room, they will eventually die because their
>> bodies
>> >>expel C02 (a product of catabolic metabolism) and
>> >>convert oxygen to H20 by dumping electrons onto it
>> at
>> >>the end of the electron transport chain within the
>> >>mitochondria of their cells. When you open the
>> door of
>> >>the room, the air will be saturated with CO2, but
>> the
>> >>pressure will still be at or very, very near 1
>> atm.
>> >>Most people think that the CO2 a person breathes
>> out
>> >>is the oxygen they breathed in with a C attached
>> to
>> >>it. Actually, it is a completely different oxygen
>> that
>> >>was stripped of a carbohydrate during a catabolic
>> >>reaction.
>> >>
>> >>
>> >>__________________________________________________
>> >>Do You Yahoo!?
>> >>Kick off your party with Yahoo! Invites.
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>> >>
>> >
>> >--
>> >Alan D. Secor
>> >e-mail: secor@btv.ibm.com
>>
>>
>>
>
>
>__________________________________________________
>Do You Yahoo!?
>Kick off your party with Yahoo! Invites.
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>