|
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.
From: owner-personal_submersibles@psubs.org [mailto:owner-personal_submersibles@psubs.org] On Behalf Of Akins Sent: Wednesday, January 26, 2005 3:17 AM To: personal_submersibles@psubs.org Subject: Re: [PSUBS-MAILIST] insults and incorrect hydrogen/vacuum assumptions on pressure equalization of battery pods and trolling motors. 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.
-- -- |