Oxygen -> nitrox rebreather?

Scoop UK

Scoop UK

New Member
Just a question on some theory that has been sloshing around my brain and feel I need to resolve...

Is there any reason why someone couldn't take a bog standard oxygen rebreather and instead of 'driving' the unit on 100%, instead run it on 50 or 32 % for example. I guess there is the risk of some o2 drop as with a pSCR but is it possible?

Cheers, hopefully someone can satisfy my curious brain.
 
Unless you increase the flow to replenish the gas I think the pO2 drop would be too much. but.............:plotting:just don't purge the unit with O2 before diving (or your lungs). That way there is some N2 in the loop (which should remain pretty constant) and you just replace the metabolized O2.
Later,
John
 
Scoop UK said:
Just a question on some theory that has been sloshing around my brain and feel I need to resolve...

Is there any reason why someone couldn't take a bog standard oxygen rebreather and instead of 'driving' the unit on 100%, instead run it on 50 or 32 % for example. I guess there is the risk of some o2 drop as with a pSCR but is it possible?

Cheers, hopefully someone can satisfy my curious brain.
Click to expand...

That would make it a semi closed rebreather - with a ton of issues. You'd need a OPV - mine doesn't have an OPV so I would have to add one or exhale through my nose every so often.

You'd need to set the flow correctly or dump the loop periodically, especially on ascent or you would go hypoxic.

Other than that, Hans and Lotte Hass used to take a lungful of air with them when they dived their Drager units and he's 90-odd now.
 
Scoop UK said:
Is there any reason why someone couldn't take a bog standard oxygen rebreather and instead of 'driving' the unit on 100%, instead run it on 50 or 32 % for example. I guess there is the risk of some o2 drop as with a pSCR but is it possible?
Click to expand...

There are many solutions to closed circuits operating on pure oxygen. Each has slightly different properties.

Osiris said:
Other than that, Hans and Lotte Hass used to take a lungful of air with them when they dived their Drager units and he's 90-odd now.
Click to expand...

Enter the depth at which the oxygen rebreather kills, because he was not washed?

Regards rc
 
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Osiris said:
You'd need to set the flow correctly or dump the loop periodically, especially on ascent or you would go hypoxic.
Click to expand...

That was my thinking. Every now and again, to prevent the o2 drop being too radical you could breathe out your nose and replenish the loop with the fresh gas. Kind of running it manually like a SCR. Would be fun to put a very basic po2 monitoring system on it and test it out.
 
There once was a site run by a diver dave
with an Italian aro chest mount he played
The, (Worlds Smallest CCR) it was named
plumbed spare air over there an oxygauge
On the net, was no better informed a page
now with sticks and stones and some spite
whats to be found is on the Rebreather Site
 
I'd actually like to re-host the old site here, as a historical reference and amusement page. I've been told by dozens of people that it was an influential part of their rebreather evolutions. I sure had fun writing it.


The "smallest rebreather" can still be found here:


World smallest CCR by Dave


Petition Wilbo, the site tech-guru for some space to host my old teardown site and I'll be happy to let the files be posted here. Might be fun to look at it all again.


Dave


.
 
Just copy the text and pics into articles Dave.

If that doesn't work it's a job for Alastair.
 
Clare said:
Just copy the text and pics into articles Dave.

If that doesn't work it's a job for Alastair.
Click to expand...



The website, as a whole, (stored on a hard drive) is a large resource, and is not something that can be simply pasted into posts. it was, for years, the most detailed and influential resource for rebreather technical descriptions and modifications, and as a "unit" ought to be preserved and hosted for posterity. I'd be happy to have the contents hosted as a sub-resource here, and think it would be an interesting thing to see again. Alastair... Knock Knock!


Dave

.
 
Dave Sutton said:
The website, as a whole, (stored on a hard drive) is a large resource, and is not something that can be simply pasted into posts. it was, for years, the most detailed and influential resource for rebreather technical descriptions and modifications, and as a "unit" ought to be preserved and hosted for posterity. I'd be happy to have the contents hosted as a sub-resource here, and think it would be an interesting thing to see again. Alastair... Knock Knock!


Dave

.
Click to expand...

+1!

It was your site that got me interested in these things in first place. Was rather sad to see it vanish.

Hopefully it can be hosted somewhere :)
 
Thanks.

It was funny, even after I did not update any content for almost 7 years that it was still on the first page of a Google search for the word "rebreather".

As far as it not being available any longer, that was never my intent. I simply forgot to re-register the domain, and when it expired someone posted a note on YD asking "what happened to NBD" and within a minute someone else registered the domain and then gloated that they had stolen the name from me. "Thanks a lot, internet" for paying back dividends to me for all of the hundreds and hundreds and hundreds of hours of work I put into the site when it was just about the only resource available for learning about these things. What's been stolen is not my loss... it's a loss to the people who wanted to read it.

And people wonder why I am less likely to share what I am working on these days. I'm still pretty peeved about the way that people who never participated in the "Beginnings" ended up treating the pioneers, egged on by tolerance of and encouragement of what can only be described as bullying on the forums.


<sigh>


It would be nice to have it re-hosted again. Here would be the obvious place.


Dave


.
 
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How much content is there - 100 megs, 100 gigs? How much of that consists of large files, like images and video? How many megs or gigs per month were being pulled down from NBD?
 
No clue on the size of the page.. it had a lot of high resolution pictures, which I described accurately as "teardowns", which then became the current day term used, well... everywhere... :o

I can have my MIS guy who had it hosted on his server work with getting it re-hosted, as long as we have a place to put it. I think that offering it as a "historical footnote page" as an addemdum to this site would be best, it would likely be read by a new generation of divers who would find value in it, and lead to some discussions.



Dave

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o2 - nitrox rebreather

there was a good thread on RBW all about this some time back.


search for o2 rebreather myths. dave sutton made some good points
 
Does anyone know what happened to Dave sutton's site? And even Tom rose's site... I know some of it is on the rebreather site.. but not everything.
When I was a trade school I loved his site and printed pages and pages.. it's to bad as homebuilder some of us have to redesign the wheel.
 
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