Scrubber Material choice...

***schford*** · 19th April 2005, 16:57

Has there been any definitive testing done on run times of different scrubber materials?

I know that obviously it will vary between units but it would give us an indication of what performs best and by roughly what percentage.

All I have been able to find is that Sofnolime 1-2.5mm performs about an hour better than sodasorb or the larger sofnalime.

Any one got any definitive figures or even personal observations of merits of other brands?

Ta

Stuart

***caveseeker7*** · 19th April 2005, 17:07

Quote: (Originally Posted by schford)

All I have been able to find is that Sofnolime 1-2.5mm performs about an hour better than sodasorb or the larger sofnalime.

What testing? What testing protocol, by whom?
What size Sodasorb, when was testing done?

***schford*** · 19th April 2005, 17:25

That was just by word of mouth that I found that out, mentioned it to a few people and seem to get universal nods that thats what they have heard too.

Perhaps it is one of those urban legends ;-) hence my initial post for some more information...

So anyone? What do you use?

peter · 19th April 2005, 17:57

From manufactures datasheets,

Sofnolime 4-8: >100 Litres CO2/Kg
Sofnolime 8-12: >140 Litres CO2/Kg
Spherasorb: >120 Litres CO2/Kg

http://www.intersurgical.com/downloads/pdf/IS51.PDF
http://www.molecularproducts.co.uk/v.../sofnolime.pdf

I use Sofnolime 8-12 in my Inspiration, because it easy for me to get and it’s not so expensive...

***caveseeker7*** · 19th April 2005, 19:32

Quote: (Originally Posted by peter)

From manufactures datasheets,
Sofnolime 4-8: >100 Litres CO2/Kg
Sofnolime 8-12: >140 Litres CO2/Kg
Spherasorb: >120 Litres CO2/Kg

The problem with that data is that the test regimen is unknown, not likely to include hyperbaric testing, and unlikely to have been done in a rebreather. In other words it's most likely theoretical data.

Ideally you would take a rebreather (or better yet, all of them), pack them as good as possible and run tests at different ambient pressures (at least at 5bar/40m and 11bar/100m). Probably several runs to accomodate inconsistencies in packing the scrubber.

There are a lot of factors figuring into the scrubber duration, ambient pressure, temperature, dwell time, RMV, amount of CO2 addition and of course scrubber design.

A while ago, for shits and giggles, I played around with the numbers a bit.
Please remember I was playing around here, these are probably not absolute numbers, but they should give an idea of the broad variations.

I used CE standards for the first three rigs that got the certification:
Manufacturer's CE rating, 40 lpm RMV and 1.6 lpm CO2 addition to 0.5% CO2 loop content.
I asumed the same parameters for the Sport Kiss as CE certification has been the goal from the start, hence the asumption the rating parameters used were the same.

For the PRISM I used the NAVY's test parameters with the lower 1.35 lpm CO2 addition rate.
The rest of the numbers are the same.

Finally, the SM1600 (pretty much MK16 center section) is based on 1.6 lpm CO2 addition, but way back when the loop content was tested to 1.0% CO2.

So for the SM1600 the duration would be shorter to the current limit, and for the PRISM there is also the possibility that duration would be less with a higher CO2 injection rate.

Unit .............Scrubber Capacity.....Rating......Scrubbing Capacity......Capacity
.............................in lbs..............in min..............in litres................in ltr per lbs

Inspiration...............5.4..................180 ...................288........................53.3
Evolution.................4.4...................12 0..................192........................43.6
Ouroboros...............6......................150 ..................240........................40

Sport Kiss................5......................150.... ..............240........................48

PRISM......................6...................... 300..................405........................67 .5

SM1600...................8.14..................284 .................454........................55.8

Since I did this a while ago with lbs instead of kg here the conversion of the manufacturer's data you posted:
Sofnolime 8-12: > 63.6 ltr/lbs
Spherasorb: > 54.5 ltr/lbs

Oddly enough, the Sodasorb tested in the PRISM would exceed the manufacturer's ratings for either Sofnolime and Spherasorb, while the 3 CE units all fall short of fully utilizing it, the Ouroboros abysmally so.

peter · 19th April 2005, 20:15

Quote: (Originally Posted by caveseeker7)

The problem with that data is that the test regimen is unknown, not likely to include hyperbaric testing, and unlikely to have been done in a rebreather. In other words it's most likely theoretical data. :

I agree.

Quote: (Originally Posted by caveseeker7)

Ideally you would take a rebreather (or better yet, all of them), pack them as good as possible and run tests at different ambient pressures (at least at 5bar/40m and 11bar/100m). Probably several runs to accomodate inconsistencies in packing the scrubber. :

Yes these numbers would be nice

Easer to compare the different units out there.

According to Martin Parker, the Inspiration time to 0.5kPa at 100m is 82 mins (40 RMV, 4C and 1.6 lpm CO2) and 55 minutes for the Evolution.

Quote: (Originally Posted by caveseeker7)

I used CE standards for the first three rigs that got the certification:
Manufacturer's CE rating, 40 lpm RMV and 1.6 lpm CO2 addition to 0.5% CO2 loop content.
:

The CE is to 0.5kPa CO2 loop content, not 0,5%, only the same on the surface.

***caveseeker7*** · 19th April 2005, 20:20

Quote: (Originally Posted by peter)

The CE is to 0.5kPa CO2 loop content, not 0,5%, only the same on the surface.

My mistake, sorry about that.
And thanks for the additional info on the APD units.
Pretty amazing how much differece ambient pressure (depth, not company

) makes,
that's why I'm always so bitchy about Micropore's testing data.

***schford*** · 19th April 2005, 20:32

Great posts

Stef - i liked the calculations - the Ouroboros really jumps out at me - for a radial design it is rather disappointing....

Wonder i there is something to be said about tower radial designs rather than donut radials!

If I had a breathing maching, Co2 sensor and my own pot we could have some fun!

It would be good if we could somehow organise some sort of testing our selves....

I mean we have all the units!

peter · 19th April 2005, 20:35

Quote: (Originally Posted by caveseeker7)

Pretty amazing how much differece ambient pressure (depth, not company

) makes,
.

Yes I agree..
That’s another thing that make it hard to compare runtimes on different units, because the testing depths isn’t the same.

Quote: (Originally Posted by caveseeker7)

that's why I'm always so bitchy about Micropore's testing data.

Yes, testing at the surface is useless for diving.

Mdemon · 20th April 2005, 09:39

Quote: (Originally Posted by schford)

Great posts

Stef - i liked the calculations - the Ouroboros really jumps out at me - for a radial design it is rather disappointing....

Wonder i there is something to be said about tower radial designs rather than donut radials!

If I had a breathing maching, Co2 sensor and my own pot we could have some fun!

It would be good if we could somehow organise some sort of testing our selves....

I mean we have all the units!

Ammers has some empirical data from her own testing. I got an e-mail of the list from a guy selling another type of material. I'll look into it...

Yes, I think our own testing would be good, as you say, we have all the equipment.

A suggestion... Perhaps someone could have a quiet chat with Martin Parker at APD on the side? They have all the testing equipment there - and they make a big song and dance about having it too. Maybe he would be amenable to some "informal" testing by ourselves - afterall, he knows his units will do well...

Your thoughts?

19th April 2005, 16:57	#1 (permalink)
*schford* Despotic Overlord Current Rebreather/s: Megalodon Sport Kiss Other Rebreather/s: Join Date: Jan 2005 Location: London, UK Posts: 3,687	Scrubber Material choice... Has there been any definitive testing done on run times of different scrubber materials? I know that obviously it will vary between units but it would give us an indication of what performs best and by roughly what percentage. All I have been able to find is that Sofnolime 1-2.5mm performs about an hour better than sodasorb or the larger sofnalime. Any one got any definitive figures or even personal observations of merits of other brands? Ta Stuart
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19th April 2005, 17:07	#2 (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: 5,498	Quote: (Originally Posted by schford) All I have been able to find is that Sofnolime 1-2.5mm performs about an hour better than sodasorb or the larger sofnalime. What testing? What testing protocol, by whom? What size Sodasorb, when was testing done? __________________ 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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19th April 2005, 17:25	#3 (permalink)
*schford* Despotic Overlord Current Rebreather/s: Megalodon Sport Kiss Other Rebreather/s: Join Date: Jan 2005 Location: London, UK Posts: 3,687	That was just by word of mouth that I found that out, mentioned it to a few people and seem to get universal nods that thats what they have heard too. Perhaps it is one of those urban legends ;-) hence my initial post for some more information... So anyone? What do you use?
(Offline)

19th April 2005, 17:57	#4 (permalink)
peter New Member Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Jan 2005 Location: Göteborg/Sweden Posts: 47	From manufactures datasheets, Sofnolime 4-8: >100 Litres CO2/Kg Sofnolime 8-12: >140 Litres CO2/Kg Spherasorb: >120 Litres CO2/Kg http://www.intersurgical.com/downloads/pdf/IS51.PDF http://www.molecularproducts.co.uk/v.../sofnolime.pdf I use Sofnolime 8-12 in my Inspiration, because it easy for me to get and it’s not so expensive... __________________ Peter
(Online)

19th April 2005, 19:32	#5 (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: 5,498	Food for thought Quote: (Originally Posted by peter) From manufactures datasheets, Sofnolime 4-8: >100 Litres CO2/Kg Sofnolime 8-12: >140 Litres CO2/Kg Spherasorb: >120 Litres CO2/Kg The problem with that data is that the test regimen is unknown, not likely to include hyperbaric testing, and unlikely to have been done in a rebreather. In other words it's most likely theoretical data. Ideally you would take a rebreather (or better yet, all of them), pack them as good as possible and run tests at different ambient pressures (at least at 5bar/40m and 11bar/100m). Probably several runs to accomodate inconsistencies in packing the scrubber. There are a lot of factors figuring into the scrubber duration, ambient pressure, temperature, dwell time, RMV, amount of CO2 addition and of course scrubber design. A while ago, for shits and giggles, I played around with the numbers a bit. Please remember I was playing around here, these are probably not absolute numbers, but they should give an idea of the broad variations. I used CE standards for the first three rigs that got the certification: Manufacturer's CE rating, 40 lpm RMV and 1.6 lpm CO2 addition to 0.5% CO2 loop content. I asumed the same parameters for the Sport Kiss as CE certification has been the goal from the start, hence the asumption the rating parameters used were the same. For the PRISM I used the NAVY's test parameters with the lower 1.35 lpm CO2 addition rate. The rest of the numbers are the same. Finally, the SM1600 (pretty much MK16 center section) is based on 1.6 lpm CO2 addition, but way back when the loop content was tested to 1.0% CO2. So for the SM1600 the duration would be shorter to the current limit, and for the PRISM there is also the possibility that duration would be less with a higher CO2 injection rate. Unit .............Scrubber Capacity.....Rating......Scrubbing Capacity......Capacity .............................in lbs..............in min..............in litres................in ltr per lbs Inspiration...............5.4..................180 ...................288........................53.3 Evolution.................4.4...................12 0..................192........................43.6 Ouroboros...............6......................150 ..................240........................40 Sport Kiss................5......................150.... ..............240........................48 PRISM......................6...................... 300..................405........................67 .5 SM1600...................8.14..................284 .................454........................55.8 Since I did this a while ago with lbs instead of kg here the conversion of the manufacturer's data you posted: Sofnolime 8-12: > 63.6 ltr/lbs Spherasorb: > 54.5 ltr/lbs Oddly enough, the Sodasorb tested in the PRISM would exceed the manufacturer's ratings for either Sofnolime and Spherasorb, while the 3 CE units all fall short of fully utilizing it, the Ouroboros abysmally so. __________________ 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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19th April 2005, 20:15	#6 (permalink)
peter New Member Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Jan 2005 Location: Göteborg/Sweden Posts: 47	Quote: (Originally Posted by caveseeker7) The problem with that data is that the test regimen is unknown, not likely to include hyperbaric testing, and unlikely to have been done in a rebreather. In other words it's most likely theoretical data. : I agree. Quote: (Originally Posted by caveseeker7) Ideally you would take a rebreather (or better yet, all of them), pack them as good as possible and run tests at different ambient pressures (at least at 5bar/40m and 11bar/100m). Probably several runs to accomodate inconsistencies in packing the scrubber. : Yes these numbers would be nice Easer to compare the different units out there. According to Martin Parker, the Inspiration time to 0.5kPa at 100m is 82 mins (40 RMV, 4C and 1.6 lpm CO2) and 55 minutes for the Evolution. Quote: (Originally Posted by caveseeker7) I used CE standards for the first three rigs that got the certification: Manufacturer's CE rating, 40 lpm RMV and 1.6 lpm CO2 addition to 0.5% CO2 loop content. : The CE is to 0.5kPa CO2 loop content, not 0,5%, only the same on the surface. __________________ Peter
(Online)

19th April 2005, 20:20	#7 (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: 5,498	Quote: (Originally Posted by peter) The CE is to 0.5kPa CO2 loop content, not 0,5%, only the same on the surface. My mistake, sorry about that. And thanks for the additional info on the APD units. Pretty amazing how much differece ambient pressure (depth, not company ) makes, that's why I'm always so bitchy about Micropore's testing data. __________________ 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.!"
(Offline)

19th April 2005, 20:32	#8 (permalink)
*schford* Despotic Overlord Current Rebreather/s: Megalodon Sport Kiss Other Rebreather/s: Join Date: Jan 2005 Location: London, UK Posts: 3,687	Great posts Stef - i liked the calculations - the Ouroboros really jumps out at me - for a radial design it is rather disappointing.... Wonder i there is something to be said about tower radial designs rather than donut radials! If I had a breathing maching, Co2 sensor and my own pot we could have some fun! It would be good if we could somehow organise some sort of testing our selves.... I mean we have all the units!
(Offline)

19th April 2005, 20:35	#9 (permalink)
peter New Member Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Jan 2005 Location: Göteborg/Sweden Posts: 47	Quote: (Originally Posted by caveseeker7) Pretty amazing how much differece ambient pressure (depth, not company ) makes, . Yes I agree.. That’s another thing that make it hard to compare runtimes on different units, because the testing depths isn’t the same. Quote: (Originally Posted by caveseeker7) that's why I'm always so bitchy about Micropore's testing data. Yes, testing at the surface is useless for diving. __________________ Peter
(Online)

20th April 2005, 09:39	#10 (permalink)
Mdemon SiegeEngine II Current Rebreather/s: Inspiration Classic Home Build Other Rebreather/s: Inspiration Classic Home Build Join Date: Feb 2007 Location: SWUK Posts: 1,931	Quote: (Originally Posted by schford) Great posts Stef - i liked the calculations - the Ouroboros really jumps out at me - for a radial design it is rather disappointing.... Wonder i there is something to be said about tower radial designs rather than donut radials! If I had a breathing maching, Co2 sensor and my own pot we could have some fun! It would be good if we could somehow organise some sort of testing our selves.... I mean we have all the units! Ammers has some empirical data from her own testing. I got an e-mail of the list from a guy selling another type of material. I'll look into it... Yes, I think our own testing would be good, as you say, we have all the equipment. A suggestion... Perhaps someone could have a quiet chat with Martin Parker at APD on the side? They have all the testing equipment there - and they make a big song and dance about having it too. Maybe he would be amenable to some "informal" testing by ourselves - afterall, he knows his units will do well... Your thoughts? __________________ www.southwestmafia.com "small minds talk about people, Average Minds Talk About Events, GREAT MINDS TALK ABOUT IDEAS!" The WRONG Attitude will get you killed. "Once the agenda-monkeys and perfect-worlders have moved on, perhaps we can do some diving?"
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