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Terry D
06-06-2005, 12:14 PM
Thought this was interesting

http://www.livescience.com/scienceoffiction/050606_breathe_underwater.html


Alan Izhar-Bodner, an Israeli inventor, has developed a way for divers to breathe underwater without cumbersome oxygen tanks. His apparatus makes use of the air that is dissolved in water, just like fish do.


(From Breathe like a fish!)

The system uses the "Henry Law" which states that the amount of gas that can be dissolved in a liquid is proportional to the pressure on the liquid. Raise the pressure - more gas can be dissolved in the liquid. Decrease the pressure - gas dissolved in the liquid releases the gas. This is exactly what happens when you open a can of soda; carbon dioxide gas is dissolved in the liquid and is under pressure in the can. Open the can, releasing the pressure, and the gas fizzes out.

Bodner's system apparently uses a centrifuge to lower pressure in part of a small amount of seawater taken into the system; dissolved gas is extracted. The patent abstract reads:

A self-contained open-circuit breathing apparatus for use within a body of water naturally containing dissolved air. The apparatus is adapted to provide breathable air. The apparatus comprises an inlet means for extracting a quantity of water from the body of water. It further comprises a separator for separating the dissolved air from the quantity of water, thereby obtaining the breathable air. The apparatus further comprises a first outlet means for expelling the separated water back into the body of water, and a second outlet means for removing the breathable air and supplying it for breathing. The air is supplied so as to enable it to be expelled back into the body of water after it has been breathed.

Human beings have been thinking about how to breathe underwater since they started swimming. This long-held desire plays an important part in one of the first great science fiction novels, Jules Verne's 20,000 Leagues Under the Sea.

It consists of a reservoir of thick iron plates, in which I store the air under a pressure of fifty atmospheres. This reservoir is fixed on the back by means of braces, like a soldier's knapsack.
(Read more about Jules Verne's diving apparatus)


(Check out this Functional Captain Nemo Diving Suit)

More recently, I distinctly remember an episode of the sixties sf series Voyage to the Bottom of the Sea in which a scientist decides that the best way to breathe underwater is to give himself gills. Alas, once equipped with gills, and fully acclimated to life in the sea, Dr. Jenkins and his associate lie in wait outside the submarine Seaview, converting every diver who emerges from the ship into mermen.


(From The Amphibians - aired Mar-08-1965)

And, of course, everyone remembers the scene in which intrepid Jedi Obi-Wan Kenobi and Qui-Gon Jin don pencil-sized breathing masks to explore the swamp lakes of Naboo in The Phantom Menace. This trick is used again in the most recent Star Wars movie.


(Hmm, perhaps those small cylinders are centrifuges...)

Read more at Like a Fish: Revolutionary Underwater Breathing System, or take a look at more inventions from 20,000 Leagues Under the Sea and the Functional Captain Nemo Diving Suit. Also, an excellent recent novel, Starfish by Peter Watts, refers to a "recycler" that can be implanted directly in the diver. Thanks to alert reader Adi for pointing this story out.

(This Science Fiction in the News story used with permission from Technovelgy.com - where science meets fiction.)

normblitch
06-06-2005, 01:40 PM
:

expelling the separated water back into the body of water,

...and the eflux of post-extraction water will provide thrust, thereby making the scooter obsolete as well...

I'll take TWO, assuming that the spin torque for the separator comes from either a Perpetual motion machine, or the AC current fed from the tin-foil lining of my dive beenie...

Norm

Tegg
06-06-2005, 02:03 PM
Shouldn't be to long before I can get my gills installed... :-D

OFG-1
06-06-2005, 02:32 PM
I'm still waiting for a combination rectal air convertor/regulator/rebreather/fusion chamber.

BillBowden
06-06-2005, 03:57 PM
this contraption will give my Yellow Box of Death a run for it's money.

Where do I sign up? Is a side-mount version available?

FW
06-06-2005, 06:48 PM
Where do I sign up? Is a side-mount version available?

I'm already working on it :-D

Gary
06-07-2005, 01:27 AM
I'm guessing the power supply needed to run the centrifuge would be bulkier than tanks and that for cave the low oxygen in the water would make it even more difficult. :(

normblitch
06-07-2005, 06:40 AM
I'm guessing the power supply needed to run the centrifuge would be bulkier than tanks and that for cave the low oxygen in the water would make it even more difficult. :(

"Nothing Difficult is Ever Really Easy"

Norm
(visualizing whirled peas)

normblitch
06-07-2005, 06:44 AM
I'm still waiting for a combination rectal air convertor/regulator/rebreather/fusion chamber.

I think I caught a whiff of it at DEMA...
AFAIR, it was called the Flatis Barosimian RB Model 2

(Model 1 was a prototype that mysteriously exploded, leaving a brownish mushroom cloud)

Just so you know...
nhb

crazyduck
06-07-2005, 09:16 AM
I have seen a picture describing this- Ah heck here is a link because I refuse to post it.
http://www.rebreatherworld.com/gallery/showimage.php?i=212&c=19
Diver clicking on this link- you have been warned- no nudity, but Yuck!

Know that we have past the kaka…

Prism manufacture known as Steam Machines has talked about making a side slung bailout rebreather- time table is unknown at this time. :-D

Regards, Andrew

REastman
06-07-2005, 11:06 AM
I have seen a picture describing this- Ah heck here is a link because I refuse to post it.
http://www.rebreatherworld.com/gallery/showimage.php?i=212&c=19
Diver clicking on this link- you have been warned- no nudity, but Yuck!

Know that we have past the kaka…

Prism manufacture known as Steam Machines has talked about making a side slung bailout rebreather- time table is unknown at this time. :-D

Regards, Andrew

Oh man...I was about to fix me some lunch but never mind...That was just sick.

John L.
06-07-2005, 11:48 AM
I'm still waiting for a combination rectal air convertor/regulator/rebreather/fusion chamber.


Now thats a good Idea! I like to smell my own farts anyway, and theres probably enough power to even run a scooter. You would have to have a back-up strainer incase you had too much taco bell the night before, and one the the farts had lumps!

crazyduck
06-07-2005, 02:44 PM
Oh man...I was about to fix me some lunch but never mind...That was just sick.

OK, I owe you lunch.

crazyduck
06-07-2005, 02:53 PM
I talked to a friend who is even more of a nut about rebreathers than me.

It seems that this is old news.
US Patent office- No. 3,333,583
Dated- Aug 1st 1967
Author- Bruce R. Bodell
Labeled- Artificial Gills.

As stressed by others certain nasty restrictions apply.
Apparently, the infinity for Oxygen in fish systems are a lot better at maintaining and capturing oxygen that cross the gills of the fish.

While an interesting idea- I will ogling my rebreather thoughts because that is sure thing.
Besides we still need bailout at the end of the day.

Andrew

Dave Lizdas
06-07-2005, 05:48 PM
so, what'll happen when you swim this thing through a hydrogen sulfide layer?

Anyone?

Aside from that and the fact it needs a motor and batteries, there's very little dissolved oxygen in most caves. on the otherhand, a spinning centerfuge could act as a gyroscopic stabilizer, helping to maintain the diver's trim. cuz you know the guy who tries this thing out will need it... think I'll just leave those details for someone else.

folks have paid for antigravity and UFO engine patents too. Priorities, people! I want my flying car first.

FW
06-08-2005, 07:02 AM
This is a crosspost from the rebreather list server. The writer is a chemist.
----------------------------------------------------------
Don writes.............
Shear and utter bullshit!!!!!!!!
The boy is preparing a scam in the hope of hooking "investors".
Oxygen at the surface, where it is in contact with air, and where it
will be in the highest concentration, is at best 12 parts per million (ppm)
Assuming the same solubility for nitrogen, air would be therefore be 60
ppm, at the surface!
His claim of 1.5% at depth translates to 1.5 parts per hundred, about a
factor of 10,000 too high!
Also, fish are cold blooded and use less oxygen.
When we breath, we use a mere fraction of the available oxygen (less
than 10% I think), which is why we can apply CPR by breathing into another person's mouth.
His claim of being able to separate the gases at depth is also absolute
crap.
Cheers,
Don
PS If anyone is going to send this guy money, have them pass me the
money first and I will pass it on for them.
end Quote.................

Dwain
06-08-2005, 08:31 AM
The surface area needed to separate water into the component parts would be too great of an area and the deeper you go the surface area will have to increase. Then there is the byproduct called brine. This has to be scrapped away from the surface to allow filtration (osmosis). Even if electrolyze is used you still end up with these byproducts that have to be gotten rid of.

OFG-1
06-08-2005, 11:57 AM
I have seen a picture describing this- Ah heck here is a link because I refuse to post it.
http://www.rebreatherworld.com/gallery/showimage.php?i=212&c=19
Diver clicking on this link- you have been warned- no nudity, but Yuck!

Know that we have past the kaka…

Regards, Andrew

DAMN MAN! You have taken a pretty fair joke and turned it into something repulsive, disgusting, rude, and socially unacceptable.

GOOD JOB!!! :armybravo