YD Scuba Diving Forums banner

1 - 12 of 12 Posts

·
Registered
Joined
·
246 Posts
Discussion Starter · #1 ·
Imported post

Hi,

Ive only been diving the last 3 months or so I dont know every thing yet
.I just want to ask on using ordinary air 21% oxy 79% nitro, why cant they replace the nitro with another inert gas, so you still have 21% oxy but 79% of another gas so you dont have to worry about nitrogen problems and perhaps dive much longer. Im not talking about using nitrox or Helium.


Also on this liquid breathing just after the Abyss came out a year later I saw on the news talking about liqud breathing, they did show a rat in a large test tube swimming happily in this fluid breathing it.  Has any one been daft enough to try it under water yet?
Thanks Tony.
 

·
Just not enough dive time.
Joined
·
9,135 Posts
Imported post

Tony
AIU the Nitrogen is not used but absorbed by the body tissues, but it isnt an inert gas as such. Therefore the replacement gas would need to be unused and not absorbed either or if absorbed would need to off gas quicker than Nitrogen else whats the point. I should imagine such a gas would be too costly or impractical to use for other reasons.
He can be used instead of N but is very costly. Pure oxygen could be used as it is metabolised by the body but 100% 02 wouldnt do you a lot of good past 6m (pp1.6 - good night Vienna) approx. Plus the CNS clock would bite your bum on all but the shortest of dives, that is if your lungs managed to last long enough.
Basically we aint supposed to dive, but being as we are pretty tasy creatures we do and we 'bend' the rules a bit.

Matt
 

·
A short fat well off crap cave diver. Likes wrecks
Joined
·
15,343 Posts
Imported post

Helyox is what you are probably refering to. Heleox is O2 and Helium and nothing else. Great stuff but the cost of a fill for a twin set is about £1 per 1% He so a 79% he fill will set you back errrr £79.

I use Trimix and a 18%02/40%he fill costs me £42

Other problem is the less dense gas on gasses much quicker than Nitrogen so a 40m dive on air for 30mins would give you 58mins deco where as on Heleox 21/79 you would have 767mins deco. That is not a misprint thats 12 hours and 78mins deco on heleox

As for liquid O2 I understand its posible but there are much more pressing problems that occur at depths where it would be necessary and ROVs have put an end to most experiments in deep diving.

ATB

Mark Chase
 

·
Banned
Joined
·
1,389 Posts
Imported post

Neon has also been used in the past, but if you think Helium's expensive, the cost of Ne is huge.  Similar lack of Narcosis to He though. It's also a 'fast' gas.
I do believe various hardy military (poss. Commercial?? Anyone know?) types have experimented with Hydrogen.  However I understand that under certain circumstances (possibly combination of PO2 and PH, curse my rotten memory  
) it can get a wee bit unstable. As in loud bang, diver reduced to Chum.


Again relying on my rotten memory, I seem to remember the fluid breathing experiments with rats.  Only problem was expelling the fluid afterwards caused the rats to snuff it.

Just as an aside - did you know the Inspiration's CE certified to 40m on Air, 100m on Heliox - not Trimix?  Bugger that, I'm sticking with Heliair and Brussels can go swing.
 

·
Registered
Joined
·
246 Posts
Discussion Starter · #5 ·
Imported post

Thinking back i did read a post very briefly about using CO2 as a inertgas for breathing any truith to this?
 

·
Registered
Joined
·
93 Posts
Imported post

[b said:
Quote[/b] (Rob Evans @ Sep. 17 2003,19:49)]Neon has also been used in the past, but if you think Helium's expensive, the cost of Ne is huge.  Similar lack of Narcosis to He though. It's also a 'fast' gas.
I do believe various hardy military (poss. Commercial?? Anyone know?) types have experimented with Hydrogen.  However I understand that under certain circumstances (possibly combination of PO2 and PH, curse my rotten memory  
) it can get a wee bit unstable. As in loud bang, diver reduced to Chum.
Neon is a slow gas. Good for very deep very short dives as it goes into tissues very slowly, but once there takes an age to come out again.

Hydrogen explodes when Fo2>0.04 (4%). It also produces a narcotic effect similar to LSD according to my info (GUE Tech Handbook). Basically you need to 'flush' your lungs with a low O2 gas before you start breathing anything with H2 in it. Though quite how you know your lungs are sufficiently flushed is something I'm unwilling to experiment with...

Impressive way to go though!

HTH,

Chris
 

·
Registered
Joined
·
246 Posts
Discussion Starter · #9 ·
Imported post

[b said:
Quote[/b] (MATTBIN @ Sep. 17 2003,17:01)]Tony
AIU the Nitrogen is not used but absorbed by the body tissues, but it isnt an inert gas as such. Therefore the replacement gas would need to be unused and not absorbed either or if absorbed would need to off gas quicker than Nitrogen else whats the point. I should imagine such a gas would be too costly or impractical to use for other reasons.


Matt
Hi Matt,
I was thinking more on another type of gas where unlike nitrogen you could breath it and dive an unlimited time except for "tank time", you would not have to do deco stops and no SI`s, this gas would have to be totally harmless. Just a thought.
As to too costly or impractical If there was such a gas it would be too costly but if every one wanted it the cost would come down.  Just to make a small point cars are still runing on petrol this aint going to last forever at the moment alternate fuels are expensive, when oil runns out alternate fuel prices will fall as every one will need it.
Tony
 

·
Just not enough dive time.
Joined
·
9,135 Posts
Imported post

[b said:
Quote[/b] ]when oil runns out alternate fuel prices will fall as every one will need it
Not necesarily - supply and demand is what causes price to drop or rise.
It may be that the price will drop because it will be more economic to produce that at present.

Matt
 

·
Finless: You couldn't invent him...
Joined
·
23,946 Posts
Imported post

[b said:
Quote[/b] (Rob Evans @ Sep. 17 2003,21:09)]Er, no.  CO2 is very nasty stuff indeed. Unless you're a plant.
Or green, possibly.  
 

·
Registered
Joined
·
246 Posts
Discussion Starter · #12 ·
Imported post

[b said:
Quote[/b] (Finless @ Sep. 18 2003,11:00)]
Rob Evans said:
http://www.yorkshire-divers.co.uk/iB_html/non-cgi/emoticons/rock.gif[/IMG]
are we talking little green men?
 
1 - 12 of 12 Posts
Top