Bill, you are way too sensitive! Vance is trying to help,
not insult you. Please accept his comments in the spirit they were given.
Further to the discussion: Batteries vent hydrogen all
the time. They off-gas most when charging, next most on deep discharge, next
most on normal discharge, and the least when just sitting. But they do
off-gas all the time. If you let your sub sit for a long time, an amount of
hydrogen gas will collect in your pod and perhaps your motors. The longer you
leave hydrogen gas, the more it gets everywhere.
The hydrogen gas molecule is small enough that most check
valves do not prevent it from passing by the check valve. Hydrogen gas will
also easily pass up the inside of a wire jacket.
Hydrocaps are great, so long as you do not
produce hydrogen gas faster then they can recombine it. Yes that can be
determined and the correct hydrocaps used.
Using a hydrolator has limited value as it will only
recombine the hydrogen gas that passes by it. They are not a magnet for
hydrogen gas causing some kind of convection, beyond the point of trying to
maintain a balance in the quality of the air in your pod. If I was going your
route, I would mount that hydrolator right at the entrance to the motor tube.
All this to say that hydrogen gas is highly explosive and
extremely dangerous anywhere, but especially in a sub. Back to Vance's
comments; please be cautious that you are not overly confident in your design.
When dealing with hydrogen gas, a mistake can be more expensive than just the
cost of the sub.
Dear Vance.
I never claim to have all the answers Vance. For
you to infer that my attitude is one of such is insulting to me. I do not
insult people here and do not appreciate it being done to me. I am always
polite and would never dream of saying something like that to
you.
I never said "I got to die sometime", what I said
was submarines and diving in general are not particularly safe in
themselves.
Neither sport are as safe as sitting and watching
t.v. now are they? I have said many times that I am no expert. But I do have
some knowledge also.
I never minimize risks and I too believe risks
are to be managed. That is why I am going to use BOTH hydrocaps on ALL my
battery cells as well as hydrolators in my battery pod.
I am totally familiar with George Peroni and the
hydrocap corporation's products. Both their hydrocaps and their hydrolators
that you mention as being bracket mounted. I may have to build a sliding
battery tray that allows me to
slide my 4 batteries out of the battery pod for
charging rather than charge the batteries while encased within the battery pod
and using a forced air system to vent the hydrogen while charging. I was
thinking of doing this quite some
time ago before I even considered a forced air
system for recharging. Yes, I may have to replace my O ring seal a bit more
frequently because of this, but that is minor. One thing that will do is
minimize penetrations thru the hull of my
battery pod that would have to be made for a
forced air system. The less holes I have to make leakproof the better I like
it.
In so doing I will be able to check on my
hydrocaps while they are charging. And if one is bad replace it. If one of the
hydrocaps happened to go bad while i was submerged, then the hydrolator would
take up the slack and when I got home
and slid the batteries out to recharge I would
find the bad one and replace it. Also each time I recharged the batteries I
can check the acid level and replenish it if necessary. By putting disposable
diapers in the bottom of the battery pod
I can collect any small amount of water that the
hydrolators deposit into the bottom of the battery pod and preclude that small
amount of water from splashing by the diapers absorbing them.
I am sorry but you are in error when you say you
use oxygen from the surrounding atmosphere to combine with the hydrogen to
create water. The oxygen you need is already in the water in your battery as
is the hydrogen also.
The water acid mix in the batteries contains the
oxygen in the water already that you need to recombine with the hydrogen to
create water. You do not need any oxygen from the surrounding atmosphere. I
remember the science project in
school where the teacher ran an electrical
current thru the water and collected the oxygen in one test tube and the
hydrogen in the other, and then lit the hydrogen test tube with a match and we
all heard it go POP. Then he blew the match out
and dropped it into the test tube of oxygen and
it burst into flame again.
That hydrogen was created by electrically
seperating hydrogen and oxygen which is what water is. Therefore when you
create the hydrogen you also create the oxygen and do not need an outside
atmosphere oxygen source. The hydrocaps and hydrolator
simply recombines the two that were seperated
electrically and turns them back into water.
Therefore there would not be a vacuum on the pod
at all. But even more than this, with my pressure equalization system even if
what you said were true about a vacuum in the pod, my scuba regulator would
sense any vacuum within the pod and vent air into it until there was no longer
a vacuum just as it would normally do since if there were a vacuum within the
pod the water pressure on the outside would be more than within the pod and my
scuba regulator would vent air into the pod to compensate. So in any event
there would never be a vacuum in my battery pod.
But as I said that would not be necessary because no vacuum would exist because no
oxygen from the pod itself would be used up in the recombining of the two
gases to reform water. Just the oxygen and hydrogen that were seperated
electrically from the battery water and recombined.
To further the safety margin, my battery pod and
motor will be getting fresh inputs of air from my scuba regulator as I dive
and the expanding air will be exhausted thru the scuba regulator as I accend.
Thus further diluting and or purging any possible very, very small
trace
amounts of hydrogen that could only form
in the battery pod if BOTH my hydrocaps AND my hydrolators failed which
is highly unlikely. By using this system and paying careful attention to my
batteries during their charge cycle, there should not be a problem and I
believe safety should be at a maximum..
Of course I could always get swallowed by a whale
or attacked by a giant squid.
If my posting here somehow makes people think I
believe I have all the answers, then I can just stop posting. I have my wetsub
and my knowledge and I can always leave if people get insulting or things
cease to be fun. So if you think I am of any value at all, please be polite as
I always am. I take a great deal of time to post and try to help out here.
Most of my posts are time consuming for me and I do this for fun. When it is
not fun anymore, I will not do it.
Guarded Regards,
Bill Akins.
----- Original Message -----
Sent: Thursday, January 27, 2005 4:07
AM
Subject: Re: [PSUBS-MAILIST] Wetsub
carrier water transport systems
Bill,
There's a problem with having all the answers, old bud. You'll miss
one of the questions. That Gaelic shrug and the "I got to die sometime"
thing will get you killed, given the opportunity. Risks are to be managed,
not taken.
The Hydrocaps are great. But they get poisoned when
splashed from underneath with acid and lose efficiency. And the only way to
tell if they are working is to put your hand on them while charging. They
warm up. A cold one isn't making it. And you can't do that in the battery
pod.
Towing the sub will rock the pod, generate some splash, and
potentially posion the caps. Unless the folks in Miami have redesigned it,
that is. They also have caps that are bracket mounted. These return water to
the pod, rather than the battery, so don't rejuvenate the acid. Also, you
use oxygen from the surrounding atmosphere in combination with hydrogen to
make the water, so the pods will be under a slight, but noticeable vacuum
after heavy use. You have to vent.
DC motors make sparks for a
living, so you might want to think about putting a baby blow torch in there
with your hydrogen generation unit. Potting each wire might not be necessary
if you just packed RTV or something into some part of your tubing around
them. Then supply air from the same source as your pod equalization, but use
dedicated tubing.
Vance
Vance
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