[Date Prev][Date Next] [Chronological] [Thread] [Top]

RE: [PSUBS-MAILIST] Pressure air drive.

The air-powered sub certainly sounds interesting from the perspective of simplicity. But what an amount of tank-filling this would imply in preparation for a dive -- portable compressors take a while to fill a single 80, and an air-powered PSUB would probably need 10-20 times that much air. 

Incidentally, this brings to mind a book I have about a sub called Aquarius (but not Phil's Aquarius), which was written by one of Cousteau's original divers. Its years since I read it and I've forgotten the details, but it was about a sub that generated its own gases through a chemical reaction. It was designed to lift heavy objects off the bottom. Very original approach, but although they built it they never really finished the job. The designer makes an amazing yet un-substantiated claim to have built and tested a sub inside a Russian POW camp in WWII, using junk lying around in the camp. If the story was true, he sailed out of camp and pulled off what was at the time the world's deepest dive, then went back. Yes, really. Carsten, you have a comprehensive sub library... d'you have this book too?

Anyway, to answer the question on max dive depth. Solo has a design crush depth of 3,086 feet. However, how close she gets to that depends on how deep I get to test her. Ideally I would test to 2,000 feet and take her to 1,000. But I suspect finding a place 2,000 feet deep and someone with a cable that long might not be easy. 

rgds,

Alec  

-----Original Message-----
From: Carsten Standfuss [mailto:MerlinSub@t-online.de]
Sent: Tuesday, January 07, 2003 3:38 PM
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] Pressure air drive. 


Your lost range or runtime with your dual tanks concept - 
In deeps between 0 - 1000 m (0-3000 ft).. an open system   
with one 200 atmos.pressure bottle runs longer. Only if you 
go deeper than 3000 ft the dual bottle system runs longer. 

Near the surface a (200 bar) open system runs about two times longer
than your closed system.

The only good points for the dual concept = it don't change the boats
weight. And you can blow the softtanks at the end of the trial
with the half emtpy (or the half full bottle)..  
At deeps greater than 2000 m (6000 ft) the open system will not work 
- but the dual will. 

Seems only a solution for deep going psubs ? 

If you have the dual concept you can use it for deep drives 
and later switch to open cycle for the drive home near or at the
surface. 

But before you waste to much time - you should calculate 
how much storage energy a scuba tank contains and how much a lead
battery of the same size/weight.. 

I have use underwater pressure air hand drilling maschines tools 
- and they require normal 6 bar at 250 L/min. In 20 meter deep the
compressor on the surface boat was run wit 8 bars at 250 l/min. 
If you build this drilling machine as drive in a psub a 
normal size scuba bottle will be empty after about : 
10 L x 225 bar = 2250 liter divided by 250 l/min = about 9 minutes
near the surface. With a twin tanks system in 4-5 minutes.. 

Another way to calculate with compressed air: 
My 140 l/min high pressure air compressor use a 3 Kw engine. 
My 200 l/min high pressure air compressor use a 5 kw engine. 

Okay with no energy losses.. the compressor gives - driven by air (its
just a brain experiment..) one 140/3 = 47 l/min air to produce
1 kw motor output.. the other one 200/5 = 40 l/min. 

Okay - it should work to drive a small psubs with 1 Kw
so we need about 45 l/min with one 2250 liter air bottle about
50 Minutes (open system). With two storage bootles about 100 minutes
(Also open system). 
Thats is equal to 1,67 hours or with 1 KW = 1,67 Kwh. 
The size of two bottles is equal to about one big truck
lead battery of 12 V x 225 AH = 2,7 Kwh - but you can empty 
the battery capacity only to about 60 % = 1,62 Kwh. 

The big point is.. the air tanks are naturaly pressure tight
and can be storage outside with no extra cost.. and create volume there. 
The battery has to be storage inside  - or need a extra pressure 
tight container or an ambient compensator system.

Another point the weight of the two tanks is about 20 kg
the battery has 70 kg = 3,5 times the scuba tanks..

Fact is also that the german air driven torpedos of WWI 
have had a greater range and runfaster than there battery powered
colleges of WWII - but the air driven were to easy to detect.. 

Seems an air drive should be worth to investigate some brain time. 


Submadman's - one request - Which Psub (build or under construction)
is the one with the greatest deep diving possiblity ? 
Sgt.Peppers has work deep of about 100 m (328ft) 
and crush at 300 m (984 ft). 
Euronaut will have 250 m (820ft) and 535 m (1755ft)

regards Carsten


Warrend Greenway schrieb:
> 
> Not if you use dual tanks. You lose some range, but you gain depth to
> whatever your hull is good for. Obviously this requires a high pressure
> pneumatic motor.
> 
> Warren.
> 
> > I have seen on the net a diver propulsion vehicle that works with air
> > pressure, yes it works, torpedoes worked that way before.
> > but depth is limited to 30 Ft maximum
> > Herve
> > ----- Original Message -----
> > From: "Warrend Greenway" <dub@linuxmail.org>
> > To: <personal_submersibles@psubs.org>
> > Sent: Monday, January 06, 2003 10:04 PM
> > Subject: Re: [PSUBS-MAILIST] CO2 Scrubber
> >
> >
> > > LOL I guess I'm chuckling over here over your emphatic reply! You are
> > right, of course.
> > > I'll certainly be installing lead-acid in my first sub. Hey! That brings a
> > thought to
> > > mind...Has anyone on the list played with high pressure air for
> > propulsion? I did some
> > > calculations a few years ago, and it looked very viable for a weekend
> > diver. I was assuming
> > > a vaccum in one cylinder and 3000 PSI in another. There was a guy at WSU
> > that had a pretty
> > > cool air-powered sub, he said it worked great. You have to admit, that
> > this isn't too wild!
> > >
> > > Warren.
> > >
> > > > I second that!!!!!!!
> > > > What's wrong with a little beyond "tried and true?"  Maybe for the
> > "outside
> > > > the box thinkers," a fuel cell.  BUT a NUKE????
> > > >  Lead acid is cheep, works well and last a long time!  Not to mention
> > off
> > > > the store shelf with no strings attached.
> > > > Here Here Herve!
> > > > Dan H.
> > > >
> > > > ----- Original Message -----
> > > > From: "Mark Steed" <plutomark@mail.astate.edu>
> > > > To: <personal_submersibles@psubs.org>
> > > > Sent: Monday, January 06, 2003 5:31 PM
> > > > Subject: Re: [PSUBS-MAILIST] CO2 Scrubber
> > > >
> > > >
> > > > > Herve: I love it and thanks! As usual, my best regards, Mark Steed
> > > > >
> > > > >
> > > > > ---------- Original Message ----------------------------------
> > > > > From: "Herve" <caribsub@coqui.net>
> > > > > Reply-To: personal_submersibles@psubs.org
> > > > > Date:  Mon, 6 Jan 2003 18:17:17 -0400
> > > > >
> > > > > >Hi,
> > > > > >I dont understand why you dont want to use the sofnolime specially
> > > > designed
> > > > > >for life support systems, do you want to make your own just to save
> > $50
> > > > and
> > > > > >risk your life.
> > > > > >Amazing to see that every year divers die with market rebreathers,
> > yet
> > > > guys
> > > > > >outhere are ready to dive in carboard sub and milk cartons
> > rebreathers
> > > > and
> > > > > >try anything for the freedom of doing it.
> > > > > >A "regular" sub is ALREADY difficult and tricky to put together, why
> > even
> > > > > >considere nuclear homemade sub, flying subs, propane subs, peroxyde
> > subs,
> > > > > >and other out of your mind submersible, did anyone tried telekinesis
> > sub,
> > > > > >warp sub,  or time travel sub, is there anyone left here who wants to
> > > > build
> > > > > >just a realistic sub?
> > > > > >Herve
> > > > > >----- Original Message -----
> > > > > >From: "Warrend Greenway" <dub@linuxmail.org>
> > > > > >To: <personal_submersibles@psubs.org>
> > > > > >Sent: Monday, January 06, 2003 1:03 PM
> > > > > >Subject: Re: [PSUBS-MAILIST] CO2 Scrubber
> > > > > >
> > > > > >
> > > > > >> I understand why divers wouldn't want to, but I still do. I don't
> > > > > >> see what the problem is. You simply have to properly granulate and
> > > > > >> hydrate the calcium hydroxide. Furthermore, you can get the product
> > > > > >> from chemical suppliers properly packaged and pure for less. I
> > wouldn't
> > > > > >> need of want the coloring agent. I would be using CO2 analyzers on
> > > > inlet
> > > > > >> and exhaust to decide when to replace. Like I said though, the
> > medium
> > > > is
> > > > > >> rechargeable. I don't think you would want to if you were talking
> > short
> > > > > >> range weekend diver...
> > > > > >>
> > > > > >> Warren.
> > > > > >>
> > > > > >> > At 09:52 AM 1/6/2003 +0800, Warrend Greenway wrote:
> > > > > >> > >The basic scrubber will consist of a canister with two screens
> > > > > >> >
> > > > > >> > >calcium hydroxide is standard slaked or hydrated lime, available
> > at
> > > > any
> > > > > >> > hardware
> > > > > >> > >store for a few bucks a fifty pound sack.
> > > > > >> >
> > > > > >> > I've been on the "rebreather" listserv for a couple years since
> > this
> > > > is
> > > > > >> > another interest of mine. You might enjoy this website--
> > > > > >> > http://www.atlimp.com/pend2.htm, although he is more serious with
> > > > other
> > > > > >> > projects - http://www.atlimp.com/home.htm
> > > > > >> > other "famous" homemades -
> > > > > >> > http://www.metacut.com/rebreathers/TP2000/Default.htm (this
> > author
> > > > died
> > > > > >> > last month when the helicopter he was piloting crashed into NY
> > > > > >waterfront
> > > > > >> > at night- another dangerous activity),
> > > > > >> > http://home1.gte.net/doctrbob/CCO2.htm,
> > > > > >> > http://www.hrc.wmin.ac.uk:8080/xml/kiss/home,
> > > > > >> > http://insel.heim.at/malediven/350052/english.htm
> > > > > >> >
> > > > > >> > I don't think any serious divers would use hardware store
> > hydrated
> > > > lime.
> > > > > >> > The CO2 absorption depends on the exposure to the surface area of
> > the
> > > > > >> > sodalime "granules" and anyone who bets their life on such only
> > > > > >purchases
> > > > > >> > prepared "sodalime" from suppliers that have a consistant and
> > > > reliable
> > > > > >> > product. The sodalime is discarded and replaced in the scrubber
> > for
> > > > each
> > > > > >> > dive. source -
> > http://www.metacut.com/rebreathers//sofnolime.htm -
> > > > this
> > > > > >one
> > > > > >> > changes color as product is used up.
> > > > > >> >
> > > > > >> > William Alford
> > > > > >> > walford@dbtech.net
> > > > > >> >
> > > > > >> > Tout comprendre c'est tout pardonner
> > > > > >>
> > > > > >> --
> > > > > >> ______________________________________________
> > > > > >> http://www.linuxmail.org/
> > > > > >> Now with POP3/IMAP access for only US$19.95/yr
> > > > > >>
> > > > > >> Powered by Outblaze
> > > > > >>
> > > > > >>
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > >
> > > >
> > >
> > > --
> > > ______________________________________________
> > > http://www.linuxmail.org/
> > > Now with POP3/IMAP access for only US$19.95/yr
> > >
> > > Powered by Outblaze
> > >
> > >
> > >
> >
> >
> 
> --
> ______________________________________________
> http://www.linuxmail.org/
> Now with POP3/IMAP access for only US$19.95/yr
> 
> Powered by Outblaze