You too can breath like a fish with Gills

***schford*** · 5th June 2005, 16:31

*coughs* ye right!

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

Stuart

***Decodiver*** · 5th June 2005, 16:44

Yeah and when the centrifuge packs in you're well and truly Donald Ducked.

Cheers,

The Cynic.

**wedivebc** · 5th June 2005, 17:13

Quote: (Originally Posted by schford)

*coughs* ye right!

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

Stuart

It says the lithium battery will last for an hour. Hmmmm a single al80 will last me that. Does anyone know, is the amount of dissolved gas in water evenly distributed throughout the water column or will it get harder to extract oxygen as you go deeper?

***caveseeker7*** · 5th June 2005, 21:49

Whales must have big batteries.

abowie · 5th June 2005, 22:17

Quote: (Originally Posted by wedivebc)

Does anyone know, is the amount of dissolved gas in water evenly distributed throughout the water column or will it get harder to extract oxygen as you go deeper?

Dissolved gases equilibrate at the surface so the dissolved gas tension is largely determined by atmospheric pressure. In some circumstances there is a little more O2 dissolved at great depth because cold water sinks and the O2 gets metabolised less but the difference isn't great.

So while there are some factors that will influence O2 content of seawater (water temperature, salinity, metabolism of plants and animals etc) there's not a lot of O2 dissolved in seawater. Maybe 2 to 5 ml of O2 per litre at best.

In order to extract this O2 the gills of fish have a huge surface area and the molecules in their blood that carry oxygen (haemoglobin and others) may have very high affinity for O2. They have a number of other physiological strategies that then allow them to unload this O2 to their tissues.

Let's say that our Israeli friend's device works. If it can extract EVERY molecule of O2 in one pass, at a VO2 of 1l/min it'd have to process 200l of water per minute. Breathing air we extract perhaps 20% of the available O2 so if it extracts 20% it'd need to process a metric ton of water per minute to work.

There's one really good thing about this invention though. If it pumps out 17 l/sec of water (that's 4 gallons/sec for the metrically challenged) you won't need to buy a DPV :-)

ROB DAVIE · 6th June 2005, 01:40

Usually the Israeli's are known for hard-headed common-sense. Both of these guys sound as if they've been into the "kif" again, or at the very least fermented figs and pomegranites!

Rob

5th June 2005, 16:31	#1 (permalink)
*schford* Despotic Overlord Current Rebreather/s: Megalodon Sport Kiss Other Rebreather/s: Join Date: Jan 2005 Location: London, UK Posts: 3,673	You too can breath like a fish with Gills coughs ye right! http://www.isracast.com/tech_news/310505_tech.htm Stuart
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5th June 2005, 16:44	#2 (permalink)
*Decodiver* Administrator Current Rebreather/s: Megalodon Ouroboros rEvo Other CCR Other Rebreather/s: Inspiration Classic Inspiration Vision Evolution Sport Kiss Classic Kiss rEvo Other CCR Join Date: Jan 2005 Location: Geneva Posts: 2,179	It will all go Pete Tong. Yeah and when the centrifuge packs in you're well and truly Donald Ducked. Cheers, The Cynic. __________________ CCR/OC Trimix Instructor Trainer CCR Training to Mixed Gas in Switzerland, France, UK & Germany on Megalodon/COPIS-Megalodon/KISS/Sport KISS/Ouroboros/rEvo/Inspiration/Evolution/Sentinel www.zerogravitydiving.com Rebreather World Terms & Conditions
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5th June 2005, 17:13	#3 (permalink)
wedivebc FIGJAM Current Rebreather/s: Megalodon Other CCR Other Rebreather/s: Not Bought Yet Inspiration Classic Sport Kiss Other CCR Join Date: Feb 2005 Location: Vancouver Island BC Canada Posts: 1,410	Quote: (Originally Posted by schford) coughs ye right! http://www.isracast.com/tech_news/310505_tech.htm Stuart It says the lithium battery will last for an hour. Hmmmm a single al80 will last me that. Does anyone know, is the amount of dissolved gas in water evenly distributed throughout the water column or will it get harder to extract oxygen as you go deeper? __________________ Cheers, Dave.... Man is the only animal burdened with the knowledge he will eventually die
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5th June 2005, 21:49	#4 (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: 5,435	Whales must have big batteries. __________________ 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.'!"
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5th June 2005, 22:17	#5 (permalink)
abowie Fighting Girl Current Rebreather/s: Sport Kiss Other Rebreather/s: Join Date: May 2005 Location: Land of Oz Posts: 573	Quote: (Originally Posted by wedivebc) Does anyone know, is the amount of dissolved gas in water evenly distributed throughout the water column or will it get harder to extract oxygen as you go deeper? Dissolved gases equilibrate at the surface so the dissolved gas tension is largely determined by atmospheric pressure. In some circumstances there is a little more O2 dissolved at great depth because cold water sinks and the O2 gets metabolised less but the difference isn't great. So while there are some factors that will influence O2 content of seawater (water temperature, salinity, metabolism of plants and animals etc) there's not a lot of O2 dissolved in seawater. Maybe 2 to 5 ml of O2 per litre at best. In order to extract this O2 the gills of fish have a huge surface area and the molecules in their blood that carry oxygen (haemoglobin and others) may have very high affinity for O2. They have a number of other physiological strategies that then allow them to unload this O2 to their tissues. Let's say that our Israeli friend's device works. If it can extract EVERY molecule of O2 in one pass, at a VO2 of 1l/min it'd have to process 200l of water per minute. Breathing air we extract perhaps 20% of the available O2 so if it extracts 20% it'd need to process a metric ton of water per minute to work. There's one really good thing about this invention though. If it pumps out 17 l/sec of water (that's 4 gallons/sec for the metrically challenged) you won't need to buy a DPV :-) __________________ Andrew Bowie Rebreather-friendly Buddy
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6th June 2005, 01:40	#6 (permalink)
ROB DAVIE Administrator Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Feb 2005 Location: HOUSTON, REPUBLIC OF TEJAS Posts: 1,120	Usually the Israeli's are known for hard-headed common-sense. Both of these guys sound as if they've been into the "kif" again, or at the very least fermented figs and pomegranites! Rob __________________ [SIZE=2]"CC Rebreathers will become a viable part of tech diving [U]WHEN PIGS FLY[/U]!!"--GI3[/SIZE]
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