The Future of Rebreather Diving?

**SeaBass** · 26th November 2007, 07:06

Ran accross this page on the web.

http://www.isracast.com/Articles/Article.aspx?ID=63

Still a ways from prototype but is this the future of rebreather diving?

--SB

***caveseeker7*** · 26th November 2007, 07:28

That's been around for a few years, the article you linked to is from 2005.
Someone did the math, I think on Dive-Oz, calculating the amount of water needed through the system in order to generate enough O2, and it was massive. For which you'll probably need a massive power supply, too.

Anyway, couple of years and I don't recall any reports or pictures of people seeing it in the water. Neat idea, though, seems to work well for fishes.

Abbo · 26th November 2007, 08:16

You say that electronics and water don't mix well, but lithium, oxygen and water are an especially dangerous mixture. Sony, San'yo and Matsushita, have all had a very tough time from overheating and exploding battteries in 2006 and 2007 from rapid discharge. The article says a 1kg battery, but two is one and one is none: you'll end up needing 2kg. That's a lot of unstable battery to be strapped to.

If the apparatus could extract 100% of the oxygen, it would need to process 200 litres a minute to produce 1 litre of oxygen. Allowing for inefficiencies and high work rates, it would need to be able to handle peak rates of over 500 litres - half a tonne a minute. That kind of flow rate would require a lot of energy to shift, and would have a non-trivial impact on the diver's movement.

Unlike fish, which have >90% efficiency, humans only metabolise 20% of the oxygen passing through their lungs. You would therefore need a rebreather to scrub the CO2 and send the oxygen back to the lungs.

You would also need bailout, because the system would have far more potential failure points than a normal eCCR.

In the end, I can't see that this system would really save much of the clobber of a rebreather. And though the inventor says that people are lining up to test it for him, I know I would rather watch than take part...

David Pye · 26th November 2007, 10:08

Nigel Hewitt debunked this one a while back.

I think the short of it was that it could only supply enough O2 for a rebreather, and wouldn't be able to be used opencircuit.

Which raised the point: Why replace a nice, reliable 3 litre steel cylinder with a dodgy high-flow machine with many more points of failure?

**nigelh** · 26th November 2007, 10:24

Quote: (Originally Posted by David Pye)

Nigel Hewitt debunked this one a while back.

Oh! Extra credit?

Abbo · 26th November 2007, 10:54

Quote: (Originally Posted by nigelh)

Oh! Extra credit?

An Aladdin's Cave! Thanks for sharing it. Have some green.

***caveseeker7*** · 26th November 2007, 12:22

Quote: (Originally Posted by Abbo)

If the apparatus could extract 100% of the oxygen, it would need to process 200 litres a minute to produce 1 litre of oxygen. Allowing for inefficiencies and high work rates, it would need to be able to handle peak rates of over 500 litres - half a tonne a minute. That kind of flow rate would require a lot of energy to shift, and would have a non-trivial impact on the diver's movement.

In other words, you get not only an UBA, but also a scooter, and one that hauls ass!

Also solves the bailout problem: If in doubt aim up!

Nigel, just read it now, good going.

Padowan · 26th November 2007, 14:23

I looked at the schematic in the article, and it said that the water flow through the pump was 2000 LPM - that's 2 cubic metres a minute, or 120cubic metres per hour! I know a bit about pumps, and 120m3/h is not a small pump by anyones imagination!

**SeaBass** · 27th November 2007, 01:29

Quote: (Originally Posted by Abbo)

If the apparatus could extract 100% of the oxygen, it would need to process 200 litres a minute to produce 1 litre of oxygen. Allowing for inefficiencies and high work rates, it would need to be able to handle peak rates of over 500 litres - half a tonne a minute. That kind of flow rate would require a lot of energy to shift, and would have a non-trivial impact on the diver's movement.

So what your saying is the picture is a bit deceiving?

Gobfish1 · 27th November 2007, 02:06

i cant dive to 90m on o2 ,,,,

26th November 2007, 07:06	#1 (permalink)
SeaBass Thom Susko Current Rebreather/s: Megalodon Ray Home Build Other Rebreather/s: Not Bought Yet Ray Home Build Join Date: Jul 2006 Location: San Clemente, CA Posts: 232	The Future of Rebreather Diving? Ran accross this page on the web. http://www.isracast.com/Articles/Article.aspx?ID=63 Still a ways from prototype but is this the future of rebreather diving? --SB
(Online)

26th November 2007, 07:28	#2 (permalink)
*caveseeker7* Who loves ya, baby Current Rebreather/s: Sport Kiss Other Rebreather/s: Prism Topaz Join Date: Jan 2005 Location: Too far from Neverland Posts: 5,451	Re: The Future of Rebreather Diving? That's been around for a few years, the article you linked to is from 2005. Someone did the math, I think on Dive-Oz, calculating the amount of water needed through the system in order to generate enough O2, and it was massive. For which you'll probably need a massive power supply, too. Anyway, couple of years and I don't recall any reports or pictures of people seeing it in the water. Neat idea, though, seems to work well for fishes. __________________ Cheers Stefan "Political Correctness is a doctrine, fostered by a delusional, illogical minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.!"
(Offline)

26th November 2007, 08:16	#3 (permalink)
Abbo Nicholas Smith Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Aug 2006 Location: Tokyo Posts: 445	Re: The Future of Rebreather Diving? You say that electronics and water don't mix well, but lithium, oxygen and water are an especially dangerous mixture. Sony, San'yo and Matsushita, have all had a very tough time from overheating and exploding battteries in 2006 and 2007 from rapid discharge. The article says a 1kg battery, but two is one and one is none: you'll end up needing 2kg. That's a lot of unstable battery to be strapped to. If the apparatus could extract 100% of the oxygen, it would need to process 200 litres a minute to produce 1 litre of oxygen. Allowing for inefficiencies and high work rates, it would need to be able to handle peak rates of over 500 litres - half a tonne a minute. That kind of flow rate would require a lot of energy to shift, and would have a non-trivial impact on the diver's movement. Unlike fish, which have >90% efficiency, humans only metabolise 20% of the oxygen passing through their lungs. You would therefore need a rebreather to scrub the CO2 and send the oxygen back to the lungs. You would also need bailout, because the system would have far more potential failure points than a normal eCCR. In the end, I can't see that this system would really save much of the clobber of a rebreather. And though the inventor says that people are lining up to test it for him, I know I would rather watch than take part...
(Online)

26th November 2007, 10:08	#4 (permalink)
David Pye CK#69 Current Rebreather/s: Classic Kiss Other Rebreather/s: Join Date: May 2006 Location: Newcastle Upon Tyne Posts: 178	Re: The Future of Rebreather Diving? Nigel Hewitt debunked this one a while back. I think the short of it was that it could only supply enough O2 for a rebreather, and wouldn't be able to be used opencircuit. Which raised the point: Why replace a nice, reliable 3 litre steel cylinder with a dodgy high-flow machine with many more points of failure?
(Online)

26th November 2007, 10:24	#5 (permalink)
nigelh New Member Current Rebreather/s: Inspiration Vision Other CCR Other Rebreather/s: Inspiration Classic Other CCR Join Date: Mar 2005 Location: Brighton, Sussex, UK Posts: 839	Re: The Future of Rebreather Diving? Quote: (Originally Posted by David Pye) Nigel Hewitt debunked this one a while back. Oh! Extra credit? __________________ nigelh Last edited by nigelh : 26th November 2007 at 12:27.
(Online)

26th November 2007, 10:54	#6 (permalink)
Abbo Nicholas Smith Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Aug 2006 Location: Tokyo Posts: 445	Re: The Future of Rebreather Diving? Quote: (Originally Posted by nigelh) Oh! Extra credit? An Aladdin's Cave! Thanks for sharing it. Have some green.
(Online)

26th November 2007, 12:22	#7 (permalink)
*caveseeker7* Who loves ya, baby Current Rebreather/s: Sport Kiss Other Rebreather/s: Prism Topaz Join Date: Jan 2005 Location: Too far from Neverland Posts: 5,451	Re: The Future of Rebreather Diving? Quote: (Originally Posted by Abbo) If the apparatus could extract 100% of the oxygen, it would need to process 200 litres a minute to produce 1 litre of oxygen. Allowing for inefficiencies and high work rates, it would need to be able to handle peak rates of over 500 litres - half a tonne a minute. That kind of flow rate would require a lot of energy to shift, and would have a non-trivial impact on the diver's movement. In other words, you get not only an UBA, but also a scooter, and one that hauls ass! Also solves the bailout problem: If in doubt aim up! Nigel, just read it now, good going. __________________ Cheers Stefan "Political Correctness is a doctrine, fostered by a delusional, illogical minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.!"
(Offline)

26th November 2007, 14:23	#8 (permalink)
Padowan Proper Boffin Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Feb 2005 Location: Kent, UK. Posts: 518	Re: The Future of Rebreather Diving? I looked at the schematic in the article, and it said that the water flow through the pump was 2000 LPM - that's 2 cubic metres a minute, or 120cubic metres per hour! I know a bit about pumps, and 120m3/h is not a small pump by anyones imagination! __________________ Padowan The future's bright, the future's Yellow .....for now padowan.net - Latest Video: Scapa Flow Rebreather Diving
(Online)

27th November 2007, 01:29	#9 (permalink)
SeaBass Thom Susko Current Rebreather/s: Megalodon Ray Home Build Other Rebreather/s: Not Bought Yet Ray Home Build Join Date: Jul 2006 Location: San Clemente, CA Posts: 232	Re: The Future of Rebreather Diving? Quote: (Originally Posted by Abbo) If the apparatus could extract 100% of the oxygen, it would need to process 200 litres a minute to produce 1 litre of oxygen. Allowing for inefficiencies and high work rates, it would need to be able to handle peak rates of over 500 litres - half a tonne a minute. That kind of flow rate would require a lot of energy to shift, and would have a non-trivial impact on the diver's movement. So what your saying is the picture is a bit deceiving?
(Online)

27th November 2007, 02:06	#10 (permalink)
Gobfish1 Custom Title Allowed! Current Rebreather/s: Inspiration Classic Other Rebreather/s: Inspiration Classic Inspiration Vision Evolution Join Date: Apr 2005 Location: Manchester UK Posts: 363	Re: The Future of Rebreather Diving? i cant dive to 90m on o2 ,,,, __________________ Steve G Apparently not the only gay diver in the village http://drinkingliberally.org/blogs/o...nzee-glock.gif http://www.scubatunes.com/audio/vol01/mp3/HiTech.mp3
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