Extendair Cartridge Question

Scott

Good evening,

Could someone please take a minute and break out a ruler.. I am curious as to the external dimensions of the Extendair Cartridge..

I am also a bit curious if both faces are fully open to flow, or if flow is only directed through the central tunnel? If it is the latter, then if it's not too much trouble, could someone please measure that as well?

I am theorizing a homebuilt unit.. that admitadly I will probably never build... but it is fun to theorize...

Thank you very much,

Scott

Genesis

(whipping out his "test" cartridge which has been used for building up aforementioned homebuild can... )

The cartridge is a spiral-wound thing so the "last wind" makes it slightly non-circular. It will go down the bore of a 4.89" ID pipe with a bit of clearance.

The flow is down the individual channels cast into the spiral-wound material. The center core is very small (ID ~.358") and does not have any gas path in it - there is a plug in one end.

Length overall is just shy of 8".

If you're looking to build a can for these you might want to look at the rebuild kits that they sell for the Dolphin and Azimut conversion packages. These include two cones which have end-cap seals and are intended to homogenize the flow through the core. A homogeneous flow down each of the tubes is important, or you may get breakthrough while lots of unspent material remains.

The cone also provides a convenient surface on the back of it for an O-ring seal if you devise a means to hold it in the appropriate place.

You need to come up with something similar to this if you're not going to use the premade cones, because the edge of the cartridge is not symmetrical and will not seal otherwise, allowing bypass around it. That would be "bad", as they say.

Here's a couple of pictures to illustrate one potential way (as yet untested in actual use, but soon to be put to at least a dry-land test) to solve these problems..... Note the plug on the end of the cartridge - with an actual built-up can you'd probably want to use the other cone to hold together the open end of the cartridge (note how its coming slightly "open" and would allow a small amount of bypass - this would likely get worse over time-in-use) but putting it down the pipe would make it impossible to see how things fit up.

If from this you deduce that I am building such a device, you are correct

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__________________
"A venturesome minority will always be eager to get off on their own, and no obstacles should be placed in their path; let them take risks for Godsake, let them get lost, sunburnt, stranded, drowned, eaten by bears, buried alive under avalanches - that is the right and privilege of any free American."
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http://www.diversunion.org/liability.htm - Fix the Diving Cert racket

Scott

*Muhahahhahaa*

Thank you Mr. Denninger =)

Back to the evil drawing board...

(I am basically just sketching to see the best way I can package something for airline portability.... want to set it up so I can have the Extendair Cartridge interchangeable with a kittylitter cartridge)..

I have seen the adapters for the Dolphin and Azimuth.. but I am far from that position of making this... just doing some random research on where I can get parts, how much they cost, how I can package it all...

I am actually considering using solenoid operated valves for both manual dilutent, oxygen, and auto oxygen driven by a controller..

Wondering about sources for ADV's.. does everyone just use modified 2nd stages, or is there a simpler more appropriate valve already existing? (peeked at the drawings of the O2ptima)

Well I will stop rambling now...

Take care,

Scott

RebreatherNut

If we are allready on the topic of the extend air catridge, I was curious what other Rebreather divers experience is about traveling with the extend air cartridges?

Are they too bulky (size) compared to traveling with Sorb?
Troubles at the airport?
etc?

Thanks for the input,

RBN

__________________
"One minute to go, Luck-meister! Then I'll be down on you like a buzzard on a gut wagon." - ALF

Scott

Mr. Denninger,

Do you happen to have one of those adapters for the dolphin/azimuth you mentioned... if so.. could you please provide me with the overall outside dimension of those? =)

Thank you again,

Scott

Genesis

PM Sent

__________________
"A venturesome minority will always be eager to get off on their own, and no obstacles should be placed in their path; let them take risks for Godsake, let them get lost, sunburnt, stranded, drowned, eaten by bears, buried alive under avalanches - that is the right and privilege of any free American."
http://www.denninger.net
http://www.diversunion.org/liability.htm - Fix the Diving Cert racket

Jason Blackwell

I brought one cartridge back to Oz from the US late last year. (Jacksonville-Chicago-San Francisco-Sydney) I didn’t have any more problems than I would have anticipated had I been traveling with “normal” sorb. Check-in wasn’t really a problem and my bags were opened and screened (TSA note added), and it was still there when I got to Sydney. Then the domestic flight from Sydney to Brisbane, again, once explained it wasn’t an issue.

I have since completed two more international trips to from Brisbane to Santo, Vanuatu. Both trips I have been carrying up to 10 canisters. Again no problems.

Now according to all of my Aussie mates, Brisbane airport is regarded as one of the worst places to travel through in regards to airport officials, but I have not yet had any problems. See http://www.diveoz.com.au/discussion_forums/topic.asp?TOPIC_ID=11673 for more info on Brisbane airport.

As for traveling with them?

So far, if anything, I have found it was easier to travel with the cartridges as they don’t look like a dry, granular chemical as normal sorb does.

BUT, I can see a problem occurring if the officials wanted to see inside each of the foil sealed cardboard containers.

You do need to look after them so not to damage the inner cartridge, so I packed them in a hard plastic container what we call “dive tubs” and then packed my clothes etc around them to stop them moving.

I changed the scrubber medium each day, so if I had been diving the Inspiration and changing the sorb at the same intervals, I would have needed:

25kg of Sofnolime (10 by 2.5kg fills).

Diving the Optima I needed:

10 of the Micropore cartridges weigh in at 22kgs (10 by 2.2kg each).

I hope that my ease of travel continues, both for me and other Optima divers and Micropore ExtendAir users until the availability of the cartridges (and sorb) becomes commonplace. I hope this info helps.

__________________
Jason Blackwell
TDI Instructor Trainer #1358
Optima...Inspiration/Evolution...KISS...and what is next???
www.divedivedive.com.au
OZTeK '09 March 2009 Sydney, Australia www.diveoztek.com.au

jaap

I have one Extendair scrubber for my Aziumth, but I don't use it. Its far to inconvinent to get cartridges for it here in Sweden. Can measure it for you.

About ADV sources, there are several. If a p-port system is OK you can simply buy a Ray or Dolphin doseage and block the flow to get an adv.

Say this one: http://www.danshop.com/t52175.html
They also sell the part that blocks the flow.

Those Ray doseages are quite pricy new, but they appear at ebay and other places now and then.