Serial scrubber for the IDA 71

J. V. · 15th May 2007, 23:07

Quote:

I don't doubt it works for you.

Not only for me but for many other guys too. Look on The Rebreathersite, you can see some exemple.
Rebreathers Worldwide

Quote:

But, why would you want to risk it?

Risk what ? This breather works, in lake, in cave, in wreck. Sure, it have limit, but before to reach the limit it's possible to make nice dives.

Quote:

There is a reason they aren't insulated.

Insulation is made by filter running itself. It's the peripheral counter-flow which insulate the sorb.

**Dave Sutton** · 16th May 2007, 02:42

As Franken-Rig and Franken-Son's Father, let me say this:

(1): I never had an issue with C02 on a single scrubber above 35 meters.

(2): I had ONE serious hypercapnia event on a single scrubber (Franken-Son) at about 40 meters, immediately after descent. I was able to slow my breathing and get OK in about 1 minute, but it was frightening.

I limit single scrubbers now to 30 meters. Strongly suggest others do the same.

A well designed modular IDA-71 conversion will use (1) scrubber and internal diluent for shallow diving and ALSO be able to use (2) dual scrubbers and offboard diluent deeper. This is the current "best" IDA-71 method to use. What is "best" may change as we learn more.

The serial V/S parallel scrubbers is a good thing to investigate. Try it!!

JV is correct: The IDA-71 scrubber is self-insulating. The heated gas exitiing the scrubber bed surrounds the 'sorb. It's a very well designed system.

Dave

Frankie's Daddy

mverick · 16th May 2007, 04:21

Quote: (Originally Posted by J. V.)

Not only for me but for many other guys too. Look on The Rebreathersite, you can see some exemple.
Rebreathers Worldwide

Risk what ? This breather works, in lake, in cave, in wreck. Sure, it have limit, but before to reach the limit it's possible to make nice dives.

Insulation is made by filter running itself. It's the peripheral counter-flow which insulate the sorb.

I know, I read a lot on this before I did it.

Not saying you can't do it. People dive dolphins everyday and I don't. I don't like them. Not for my diving.

Risk that you get stressed and in doing so do to much work and kick out more CO2 then the scrubber can manage. That risk. It was built to have 2 scrubbers scrubbing CO2.

Your right, it insulates itself. It also has condensation on the wall because the warm moist gas passing by the outer steel metal has condensation. Condensted water on the cold outer skin of the scrubber transfers the heat to the surrounding water. And collects in the bottom of the scrubber.

Ya loose heat. But, it's how it was designed. Make the outer wall a plastic and guess what, you'll loose less heat and get less condensation. Were they trying to remove some moisture?

Why they did it that way? Don't know. They must have had a good reason. They didn't do the heat exchanger on the 72 that way. They insulated it. And left the scrubber uninsulated.

I'm thinking they had a reason for this. But, when they insulated the air heater on the 72 makes me think the answer "Because it wasn't needed". Isn't right. I'd like to know why myself.

J. V. · 16th May 2007, 09:25

[quote=mverick;115440]I know, I read a lot on this before I did it.

Not saying you can't do it. People dive dolphins everyday and I don't. I don't like them. Not for my diving.

Quote:

Risk that you get stressed and in doing so do to much work and kick out more CO2 then the scrubber can manage. That risk.

Exactly like on other breather with same sorb capacity. Why more with the IDA? Cause of insulation? I don't think. I've use it deep in cold water and have never encounted CO2 hit du to filter conception. Friend used it and have not encounted. One have encounted, cause he have push the sorb too long. I've encounted cause of (very) bad sorb storage (completly dry...). Naturally, a 2kg sorb breather need to be used as a 2 kg sorb breather. Never start a planned deep and long dive with a half used filter. It's tru for all breathers. Even with my rEvo I always start a deep/long dive with fresh filters.
Sure, if all dive must be deep and long there is better breathers than IDA 71. But IMHO, for moderate dive, range 40/50 meters, in temperate or warm waters, IDA 71 is a very correct breather if used logically. Which means for me Ray DSV or equivalent, fresh sorb, helium based diluant.
That's not theory, that's practice.
Two filters in parallel give a better WOB (just a little in fact), but can not be quantified in matter of sorb efficiency. Gas pass where it's more easy to go, if a filter is packed less hard than the other, gas pass thru this filter and just this filter. There is no sure way to know before the dive where gas will go. After it's possible to have an idea if using colour changing sorb, but it's not accurate and dangerous cause need to push the filter to obtain great colour change -and results can be different during other dives.

paulraymaekers · 16th May 2007, 09:39

just an important note: make sure the scrubber is well packed.. as the cannister is not spring loaded!

got one VERY SERIOUS CO2 hit on my IDA..

correctly packed scrubber, then 45 minutes heavy bumping on the zodiak, ida laying down on the rib, and then diving..

after 5 minutes into the dive, started feeling very uncomftable.. continued..
did not change to OC (.. my mind did not work...), rushed up the line after 15 minutes to surface..

seams I was lucky that I did not pass out...

clearly tunneling in the canister!

so check your canister befor diving..

paul

J. V. · 16th May 2007, 10:27

Quote:

so check your canister befor diving..

And breath somme minutes before jumping in the water.

Last week I've forget... the two cassettes in the rEvo filter !

I realised just before to put the breather on my back. Chance!
About IDA 71 filter, there was a square one in my box I've never tried cause I though it have poor insualtion. This morning I discuss with a friend who have an IDA too, he have tested the square canister and found it have better WOB than round one and is easier to pack -but need attention to close correctly. Now he use it, and have not encounted insulation pb (make moderate dive (70 m) in temperate water 11°). He have try serial filters too, and have found it very hard to breath.
Test is a good way to make opinion, if do carefully.

paulraymaekers · 16th May 2007, 11:10

Quote: (Originally Posted by J. V.)

And breath somme minutes before jumping in the water.

Last week I've forget... the two cassettes in the rEvo filter !

I realised just before to put the breather on my back. Chance!
About IDA 71 filter, there was a square one in my box I've never tried cause I though it have poor insualtion. This morning I discuss with a friend who have an IDA too, he have tested the square canister and found it have better WOB than round one and is easier to pack -but need attention to close correctly. Now he use it, and have not encounted insulation pb (make moderate dive (70 m) in temperate water 11°). He have try serial filters too, and have found it very hard to breath.
Test is a good way to make opinion, if do carefully.

funny, I also had a square filter, I remember that the gaspath is only +/- 5X10 cm, and double length of the filter lenght, not?? the one with the plate in the middle inside???
I measured it in the lab... 4 times higher WOB than the oval ones (seems logic as length is twice and diameter is half..)
this one was not meant to be used with granular I think!

paul

J. V. · 16th May 2007, 11:27

Quote:

funny, I also had a square filter, I remember that the gaspath is only +/- 5X10 cm, and double length of the filter lenght, not?? the one with the plate in the middle inside???

Mmm... Not sure it's the same... But if it was, it's proof that lab test and real life are not always agree.
Like our BOV and DSV .

My opinion was square filter was not designed for underwater use (gasket system need attention to be tight). But it seems to work...

J. V. · 16th May 2007, 11:30

It's this one :
Joel Seymour IDA71 Kiss

**Dave Sutton** · 16th May 2007, 13:22

Quote: (Originally Posted by J. V.)

And breath somme minutes before jumping in the water.

Last week I've forget... the two cassettes in the rEvo filter !

I realised just before to put the breather on my back. Chance!
About IDA 71 filter, there was a square one in my box I've never tried cause I though it have poor insualtion. This morning I discuss with a friend who have an IDA too, he have tested the square canister and found it have better WOB than round one and is easier to pack -but need attention to close correctly..

The square filter is great, just make sure you manufacture a screen for over the powder. it is designed for a cartridge, so when that is not used you need to trap the 'sorb with a screen. It "can" do without it, but is lots better with it. Try it, and WOB will go down even more.

Paul, if you had back luck with the square one, try again with a screen. And you are correct with the measurements.

One more thing: The square one can be *half loaded* if you use a screen over the powder. One half can remain empty. Be careful!

The Joel Seymour rig was finally assembled by Joel in my shop while he stayed here in the house. He did a nice job.
Had someone looking over the shoulder.... on his first dives with it too... with Franken-Son. Good guy!

Dave

15th May 2007, 23:07	#11 (permalink)
J. V. RBW Member Current Rebreather/s: rEvo Other Rebreather/s: Not Bought Yet rEvo Join Date: Mar 2006 Location: Lot & Savoie Posts: 249	Re: Serial scrubber for the IDA 71 Quote: I don't doubt it works for you. Not only for me but for many other guys too. Look on The Rebreathersite, you can see some exemple. Rebreathers Worldwide Quote: But, why would you want to risk it? Risk what ? This breather works, in lake, in cave, in wreck. Sure, it have limit, but before to reach the limit it's possible to make nice dives. Quote: There is a reason they aren't insulated. Insulation is made by filter running itself. It's the peripheral counter-flow which insulate the sorb. __________________ -------------------- Jacques NPSFQQA-EDS IT # 007 (remué non agité)
(Offline)

16th May 2007, 02:42	#12 (permalink)
Dave Sutton Diveshop of Horrors Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Evolution Megalodon rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,907	Re: Serial scrubber for the IDA 71 As Franken-Rig and Franken-Son's Father, let me say this: (1): I never had an issue with C02 on a single scrubber above 35 meters. (2): I had ONE serious hypercapnia event on a single scrubber (Franken-Son) at about 40 meters, immediately after descent. I was able to slow my breathing and get OK in about 1 minute, but it was frightening. I limit single scrubbers now to 30 meters. Strongly suggest others do the same. A well designed modular IDA-71 conversion will use (1) scrubber and internal diluent for shallow diving and ALSO be able to use (2) dual scrubbers and offboard diluent deeper. This is the current "best" IDA-71 method to use. What is "best" may change as we learn more. The serial V/S parallel scrubbers is a good thing to investigate. Try it!! JV is correct: The IDA-71 scrubber is self-insulating. The heated gas exitiing the scrubber bed surrounds the 'sorb. It's a very well designed system. Dave Frankie's Daddy __________________ "Silent Diving with No Bubbles and No Politics".... www.nobubblediving.com Last edited by Dave Sutton : 16th May 2007 at 02:46.
(Offline)

16th May 2007, 04:21	#13 (permalink)
mverick ScubaPimp Current Rebreather/s: Megalodon Other CCR Home Build Other Rebreather/s: Other CCR Home Build Join Date: Aug 2005 Posts: 555	Re: Serial scrubber for the IDA 71 Quote: (Originally Posted by J. V.) Not only for me but for many other guys too. Look on The Rebreathersite, you can see some exemple. Rebreathers Worldwide Risk what ? This breather works, in lake, in cave, in wreck. Sure, it have limit, but before to reach the limit it's possible to make nice dives. Insulation is made by filter running itself. It's the peripheral counter-flow which insulate the sorb. I know, I read a lot on this before I did it. Not saying you can't do it. People dive dolphins everyday and I don't. I don't like them. Not for my diving. Risk that you get stressed and in doing so do to much work and kick out more CO2 then the scrubber can manage. That risk. It was built to have 2 scrubbers scrubbing CO2. Your right, it insulates itself. It also has condensation on the wall because the warm moist gas passing by the outer steel metal has condensation. Condensted water on the cold outer skin of the scrubber transfers the heat to the surrounding water. And collects in the bottom of the scrubber. Ya loose heat. But, it's how it was designed. Make the outer wall a plastic and guess what, you'll loose less heat and get less condensation. Were they trying to remove some moisture? Why they did it that way? Don't know. They must have had a good reason. They didn't do the heat exchanger on the 72 that way. They insulated it. And left the scrubber uninsulated. I'm thinking they had a reason for this. But, when they insulated the air heater on the 72 makes me think the answer "Because it wasn't needed". Isn't right. I'd like to know why myself.
(Online)

16th May 2007, 09:25	#14 (permalink)
J. V. RBW Member Current Rebreather/s: rEvo Other Rebreather/s: Not Bought Yet rEvo Join Date: Mar 2006 Location: Lot & Savoie Posts: 249	Re: Serial scrubber for the IDA 71 [quote=mverick;115440]I know, I read a lot on this before I did it. Not saying you can't do it. People dive dolphins everyday and I don't. I don't like them. Not for my diving. Quote: Risk that you get stressed and in doing so do to much work and kick out more CO2 then the scrubber can manage. That risk. Exactly like on other breather with same sorb capacity. Why more with the IDA? Cause of insulation? I don't think. I've use it deep in cold water and have never encounted CO2 hit du to filter conception. Friend used it and have not encounted. One have encounted, cause he have push the sorb too long. I've encounted cause of (very) bad sorb storage (completly dry...). Naturally, a 2kg sorb breather need to be used as a 2 kg sorb breather. Never start a planned deep and long dive with a half used filter. It's tru for all breathers. Even with my rEvo I always start a deep/long dive with fresh filters. Sure, if all dive must be deep and long there is better breathers than IDA 71. But IMHO, for moderate dive, range 40/50 meters, in temperate or warm waters, IDA 71 is a very correct breather if used logically. Which means for me Ray DSV or equivalent, fresh sorb, helium based diluant. That's not theory, that's practice. Two filters in parallel give a better WOB (just a little in fact), but can not be quantified in matter of sorb efficiency. Gas pass where it's more easy to go, if a filter is packed less hard than the other, gas pass thru this filter and just this filter. There is no sure way to know before the dive where gas will go. After it's possible to have an idea if using colour changing sorb, but it's not accurate and dangerous cause need to push the filter to obtain great colour change -and results can be different during other dives. __________________ -------------------- Jacques NPSFQQA-EDS IT # 007 (remué non agité)
(Offline)

16th May 2007, 09:39	#15 (permalink)
paulraymaekers rEvo's daddy Current Rebreather/s: rEvo Other CCR Home Build Other Rebreather/s: rEvo Other CCR Home Build Join Date: May 2005 Location: belgium Posts: 1,638	Re: Serial scrubber for the IDA 71 just an important note: make sure the scrubber is well packed.. as the cannister is not spring loaded! got one VERY SERIOUS CO2 hit on my IDA.. correctly packed scrubber, then 45 minutes heavy bumping on the zodiak, ida laying down on the rib, and then diving.. after 5 minutes into the dive, started feeling very uncomftable.. continued.. did not change to OC (.. my mind did not work...), rushed up the line after 15 minutes to surface.. seams I was lucky that I did not pass out... clearly tunneling in the canister! so check your canister befor diving.. paul __________________ www.rEvo-rebreathers.com .... the earth is flat, Elvis is alive, and radial scrubbers give longer dwell time than axials...
(Offline)

16th May 2007, 10:27	#16 (permalink)
J. V. RBW Member Current Rebreather/s: rEvo Other Rebreather/s: Not Bought Yet rEvo Join Date: Mar 2006 Location: Lot & Savoie Posts: 249	Re: Serial scrubber for the IDA 71 Quote: so check your canister befor diving.. And breath somme minutes before jumping in the water. Last week I've forget... the two cassettes in the rEvo filter ! I realised just before to put the breather on my back. Chance! About IDA 71 filter, there was a square one in my box I've never tried cause I though it have poor insualtion. This morning I discuss with a friend who have an IDA too, he have tested the square canister and found it have better WOB than round one and is easier to pack -but need attention to close correctly. Now he use it, and have not encounted insulation pb (make moderate dive (70 m) in temperate water 11°). He have try serial filters too, and have found it very hard to breath. Test is a good way to make opinion, if do carefully. __________________ -------------------- Jacques NPSFQQA-EDS IT # 007 (remué non agité) Last edited by J. V. : 16th May 2007 at 10:35.
(Offline)

16th May 2007, 11:10	#17 (permalink)
paulraymaekers rEvo's daddy Current Rebreather/s: rEvo Other CCR Home Build Other Rebreather/s: rEvo Other CCR Home Build Join Date: May 2005 Location: belgium Posts: 1,638	Re: Serial scrubber for the IDA 71 Quote: (Originally Posted by J. V.) And breath somme minutes before jumping in the water. Last week I've forget... the two cassettes in the rEvo filter ! I realised just before to put the breather on my back. Chance! About IDA 71 filter, there was a square one in my box I've never tried cause I though it have poor insualtion. This morning I discuss with a friend who have an IDA too, he have tested the square canister and found it have better WOB than round one and is easier to pack -but need attention to close correctly. Now he use it, and have not encounted insulation pb (make moderate dive (70 m) in temperate water 11°). He have try serial filters too, and have found it very hard to breath. Test is a good way to make opinion, if do carefully. funny, I also had a square filter, I remember that the gaspath is only +/- 5X10 cm, and double length of the filter lenght, not?? the one with the plate in the middle inside??? I measured it in the lab... 4 times higher WOB than the oval ones (seems logic as length is twice and diameter is half..) this one was not meant to be used with granular I think! paul __________________ www.rEvo-rebreathers.com .... the earth is flat, Elvis is alive, and radial scrubbers give longer dwell time than axials...
(Offline)

16th May 2007, 11:27	#18 (permalink)
J. V. RBW Member Current Rebreather/s: rEvo Other Rebreather/s: Not Bought Yet rEvo Join Date: Mar 2006 Location: Lot & Savoie Posts: 249	Re: Serial scrubber for the IDA 71 Quote: funny, I also had a square filter, I remember that the gaspath is only +/- 5X10 cm, and double length of the filter lenght, not?? the one with the plate in the middle inside??? Mmm... Not sure it's the same... But if it was, it's proof that lab test and real life are not always agree. Like our BOV and DSV . My opinion was square filter was not designed for underwater use (gasket system need attention to be tight). But it seems to work... __________________ -------------------- Jacques NPSFQQA-EDS IT # 007 (remué non agité)
(Offline)

16th May 2007, 11:30	#19 (permalink)
J. V. RBW Member Current Rebreather/s: rEvo Other Rebreather/s: Not Bought Yet rEvo Join Date: Mar 2006 Location: Lot & Savoie Posts: 249	Re: Serial scrubber for the IDA 71 It's this one : Joel Seymour IDA71 Kiss __________________ -------------------- Jacques NPSFQQA-EDS IT # 007 (remué non agité)
(Offline)

16th May 2007, 13:22	#20 (permalink)
Dave Sutton Diveshop of Horrors Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Evolution Megalodon rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,907	Re: Serial scrubber for the IDA 71 Quote: (Originally Posted by J. V.) And breath somme minutes before jumping in the water. Last week I've forget... the two cassettes in the rEvo filter ! I realised just before to put the breather on my back. Chance! About IDA 71 filter, there was a square one in my box I've never tried cause I though it have poor insualtion. This morning I discuss with a friend who have an IDA too, he have tested the square canister and found it have better WOB than round one and is easier to pack -but need attention to close correctly.. The square filter is great, just make sure you manufacture a screen for over the powder. it is designed for a cartridge, so when that is not used you need to trap the 'sorb with a screen. It "can" do without it, but is lots better with it. Try it, and WOB will go down even more. Paul, if you had back luck with the square one, try again with a screen. And you are correct with the measurements. One more thing: The square one can be half loaded if you use a screen over the powder. One half can remain empty. Be careful! The Joel Seymour rig was finally assembled by Joel in my shop while he stayed here in the house. He did a nice job. Had someone looking over the shoulder.... on his first dives with it too... with Franken-Son. Good guy! Dave __________________ "Silent Diving with No Bubbles and No Politics".... www.nobubblediving.com Last edited by Dave Sutton : 16th May 2007 at 13:30.
(Offline)

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