Re: [PSUBS-MAILIST] Propane sub

["Karl Fuller" <fullerk@voyager.co.nz>]

Craig,
I imagine you entered this site with the intention of sounding out you ideas
and getting feedback. I have given my opinion and quite frankly won't again
in regard to you. If your ideas are  successful as your communication
skills, you have a very long way to go. I'll tell you something you don't
know, in your opinion we may be funny/nannies/handwringers but you are
simply  ignorant !
Karl
----- Original Message -----
From: <CWall@swri.edu>
To: <personal_submersibles@psubs.org>
Sent: Thursday, November 09, 2000 4:55 AM
Subject: [PSUBS-MAILIST] Propane sub


> (*chuckle*)   You guys are funny...;-)
>
> 1) I don't know where the comment about having to use pure oxygen comes
> from...that's a strange one.
>
> 2) A "backfire" into a ballast tank filled with propane does....nothing.
> Propane needs air to burn, and as long as the air is purged- an operator
> controlled situation- it might as well be filled with argon.   (Of course,
> you'd have to be pretty damned stupid to not include a checkvalve and
flame
> arrestor in the plumbing. Filling and isolating a separate header fuel
tank
> would obviously be a good backup to prevent failure propagation.)
>
> 3) "Have" to burn the ballast tank propane in the engine before
submerging?
> Please.  It's an option.  Venting will still be possible; you just don't
have
> to *waste* the propane if you don't want to.
>
> 4) Turbo compounding is not turbo charging.   It is energy recovery by
spinning
>  an exhaust turbine attached to an energy recovery device, in this case a
PM
> alternator.  I can't think of a good reason to turbocharge a submarine
engine
> (or at least, not one that is highly derated in the first place). I'm
surprized
>  you thought I'd suggest that, and frankly, it's a bit insulting, though
you
> might not think so. While full mechanical turbo compounding can lower fuel
> specifics, the goal here is to use a long-life, readily available engine.
Why
> drive it off it's sweet spot?  All you'd do is decrease the reliability.
>
> 5) Pneumatic compounding with a reciprocating motor would be done from the
> propane tanks, not the ballast tank, and you are right- if I were trying
to put
>  the output directly into the carb it would be too much...so don't. Send
it to
> the ballast tanks- but be aware that I'm not trying to feed an engine
> developing 5hp; that engine would be derated in cruise mode down to about
1/2hp
>  unless I was trying to buck a current and needed to speed up. That means
that
> getting as little as 1/4 hp pneumatic or even less is still significant at
low
> cruise.  And in fact, the ideal situation would be to use the propane to
> extract heat from the Honda to boost the pressure before the pneumatic
stage.
> It's a win-win situation. The propane pneumatic recip can be very small-
> perhaps even an external device with it's own prop. Since it can turn very
> slowly and with full torque, the argument could be made that with a large
prop
> one could do away with the Honda altogether.  Obviously this would not get
you
> maximum range, but there would be something to be said for it if range
didn't
> matter.  And the pnemo drive could be used for other things besides
propulsion.
>
>
> 6) As for worries that propane would be trapped in a confined space and
> ignited....well, *duh*.
>
>
>   C'mon, guys.   I work with this stuff day in and day out: hydrogen,
propane,
> DME, etc- and it just doesn't hold the terrors for me that it apparently
does
> for you. I respect it, but I also know that good engineering can tame it.
>
> I'd hate to think this list is top-heavy with "nannies", but I suppose
I'll
> find out.  So far I'm hearing expressions of fear, but I haven't heard a
single
>  objection based on things I didn't already know.  I was hoping I would!
I
> don't claim to be omniscient, but I take the lack of *substantial*
objection to
>  be an encouragement.
>
> Hand-wringing I don't need- tell me something I don't know!
>
> Craig Wall
>
>
>