Diving without oxygen bottles

[Druga Runda]

http://www.isracast.com/tech_news/310505_tech.htm

LIKE A FISH –
REVOLUTIONARY UNDERWATER BREATHING SYSTEM
An Israeli Inventor has developed a breathing apparatus that will allow breathing underwater without the assistance of oxygen tanks. This new invention will use the relatively small amounts of air that already exist in water to supply oxygen to both scuba divers and submarines. The invention has already captured the interest of most major diving manufacturers as well as the Israeli Navy.

you only need to carry a battery with you to power the machine...

hope it comes to fruition
8)

 

[London Geezer]

Well... how big is the battery? Wouldn't be much use if it's as big and heavier than the oxygen tanks...

 

[Druga Runda]

Well... how big is the battery? Wouldn't be much use if it's as big and heavier than the oxygen tanks...

well the article says a 1 kg battery to keep you going for about 1 hour underwater... so sounds OK, except what is the battery price

But if things work out I can bet with commercial production this should become affordable...

 

[Simon F]

Well... how big is the battery? Wouldn't be much use if it's as big and heavier than the oxygen tanks...

I thought it said ~1kg which would presumably would replace some of the lead diving weights.

 

[digitalwanderer]

You do realize that you never dive with oxygen bottles, right? Scuba tanks are filled with air.

Oxygen turns lethal at depths, you'll die if you try scuba diving with pure oxygen.

How does this device handle pressure regulation and such, and depth. (PADI advanced open water certified for over 20 years now 8) )

 

[London Geezer]

You do realize that you never dive with oxygen bottles, right? Scuba tanks are filled with air.

Oxygen turns lethal at depths, you'll die if you try scuba diving with pure oxygen.

How does this device handle pressure regulation and such, and depth. (PADI advanced open water certified for over 20 years now 8) )

Well pure oxygen would have rather nice effects

 

[digitalwanderer]

Well pure oxygen would have rather nice effects

Up until the dying bit, yes. :?

 

[PC-Engine]

Normal breathing of air already gets you 98% oxygen into the blood. Why would you need pure oxygen if you don't have a respiratory illness? :?

Anyway this invention is cool since 1kg is only 2 lbs and like lb said it could replace the diving weights. 2 or 3 batteries should allow over 2 hours of diving. How big and heavy is the maching though?

 

[Druga Runda]

well here is the image

and it doesn't look big...

 

[Guden Oden]

I wonder how feasible this really is. The artificial "gill" looks awfully small compared to our human lungs, and they breathe a medium that's thousands of times more oxygen-rich compared to water. Not only does that tiny cylinder need to separate out large quantities of oxygen out of water, it needs to purge carbon dioxide from the air breathed out by the diver as well. It also has to deal with breath condensation somehow; it would be bad if it filled up partially with water during a long dive.

Call me sceptical. Fish survive on the oxygen in water for a reason; they're cold blooded. Our metabolism is ~10x faster than theirs and our bodymass is many times bigger than most fish as well. This means problems for an artificial gill.

 

[London Geezer]

I wonder how feasible this really is. The artificial "gill" looks awfully small compared to our human lungs, and they breathe a medium that's thousands of times more oxygen-rich compared to water. Not only does that tiny cylinder need to separate out large quantities of oxygen out of water, it needs to purge carbon dioxide from the air breathed out by the diver as well. It also has to deal with breath condensation somehow; it would be bad if it filled up partially with water during a long dive.

Call me sceptical. Fish survive on the oxygen in water for a reason; they're cold blooded. Our metabolism is ~10x faster than theirs and our bodymass is many times bigger than most fish as well. This means problems for an artificial gill.

Nemo's not cold blooded!!! He's nice and red and warm.

 

[PC-Engine]

it needs to purge carbon dioxide from the air breathed out by the diver as well

How would that be any different than the traditional air intake/exhaust scuba gear? :?

 

[RussSchultz]

it needs to purge carbon dioxide from the air breathed out by the diver as well.

No, the exhaled air is exhaled into the water, just like a traditional scuba set up.

 

[Killer-Kris]

Fish survive on the oxygen in water for a reason; they're cold blooded.

Not to nitpick but not all fish are in fact cold blooded. Many sharks, and I believe a few species of tuna maintain a relatively stable body temperature.

 

[Mariner]

IIRC, Oxygen makes up about 21% of the atmosphere and we use about 4-5% of this 21 in each lungful. If as the link says, 1.5% of water at 200m is just atmospheric air (not oxygen), surely the pump will need to filter a hell of a lot of water to get enough oxygen for each lungful?

 

[digitalwanderer]

it needs to purge carbon dioxide from the air breathed out by the diver as well

How would that be any different than the traditional air intake/exhaust scuba gear? :?

They have those, called "re-breathers" I believe. They filter out the carbon dioxide and replenish the oxygen in the air.

They didn't work out so hot in actual practice though so never caught on.

 

[Simon F]

They have those, called "re-breathers" I believe. They filter out the carbon dioxide and replenish the oxygen in the air.

They didn't work out so hot in actual practice though so never caught on.

I kind of thought the main idea behind the rebreathers was that, because the air delivered from a standard scuba gear must match the pressure at that water depth, you end up using up the tank a lot faster at greater depths, wasting most of the air. A rebreather would improve the efficiency.

 

[Guden Oden]

How would that be any different than the traditional air intake/exhaust scuba gear? :?

Difference is that exhaust air with traditional scuba gear is just vented out into the surrounding water.

There's going to be difficult enough to harvest enough oxygen from the water to feed a human being. Now, the air mixture we breathe normally is ~70% nitrogen, where's all that gas going to come from underwater? The only realistic way around that problem is if that gill thing supplies an inert gas to mix the oxygen into and recycles it as the diver breathes in and out.

 

[Frank]

This is actually a pretty old invention. About 30 years ago the French (Cousteau e.a.) already used things like this.

It's actually quite neat and a lot like lungs. It's a large membrane that only allows oxygen to pass through. The main problems with it are getting enough water flow at the outside, oxygen flow at the inside and mixing the air to breathe.

A rebreather that filters the CO2 from the air and recirculates it (also called a recirculator, IIRC), fixes half the problems, while folding the membrane into a package and pumping water through fixes the other half.

They are or have been actually used as well, but it is even much harder to get the air mixture right than the other solutions. It looks like a wide backpack instead of a bottle, and is (IIRC) mainly used for deep sea and other extended diving. And it was quite expensive and you had to replace them fairly often.

I think, that they mostly came up with a better membrane, and use a computer to do all the hard work.

 

[DemoCoder]

Well, if the battery dies, perhaps the system is efficient enough that if you keep moving, you can get enough air to swim to the surface. You'll be like a shark. Stop moving, and you die. Unfortunately, exertion is going to bump up the CO2 needed. Still, the system would do better to somehow capture your energy expenditure underwater to help trickle-charge the battery.