Changing Sofnolime

[Pierre Farrugia]

What I do is, after a dive I clean breather and leave my scrubber on an upside down cylinder booty with a hole for the spring. Then will seal everything the following morning when everything is dry! (keeping in mind the hours done) Anyone has found a container where you can store the canister scrubber assembly and leave the head open? Does leaving the head open can damage the sensors?

[wreckweasel]

Originally Posted by Pierre Farrugia

What I do is, after a dive I clean breather and leave my scrubber on an upside down cylinder booty with a hole for the spring. Then will seal everything the following morning when everything is dry! (keeping in mind the hours done) Anyone has found a container where you can store the canister scrubber assembly and leave the head open? Does leaving the head open can damage the sensors?

Yes pierre. You need to make up a specialist, highly expensive container from 7.5mm lexan and flood it with a 80/20 neox mix.

Anything else will invalidate your warranty......

[/irony]

[Decodiver]

Originally Posted by Pierre Farrugia

What I do is, after a dive I clean breather and leave my scrubber on an upside down cylinder booty with a hole for the spring. Then will seal everything the following morning when everything is dry! (keeping in mind the hours done) Anyone has found a container where you can store the canister scrubber assembly and leave the head open? Does leaving the head open can damage the sensors?

Hi Pierre,

No it won't damage the sensors as it will be in air.

Cheers

Dave Cooper

[Mark Chase]

What I do is take the scrubber out, and put it in a sealed plastic bag on the shelf. After the second dive I will do the same but by the time I get to the third dive I will think sod it my life is worth more than £7.00 and I will bin it and re fill it

I don’t like the look of all those solid lumps that come out, 90mins diving over two dives over two weeks £7.00 for the next two dives isn’t worth worrying about. Take a flask and don’t drink their coffee or don’t go to the bar after the dive if you’re worried about £3.50. Rather that than risk dodgy lime.

ATB

Mark Chase

[BJ]

Try this for size:-

When put in contact with a acidic gas like CO2, a strong, exothermic (heat producing) reaction takes place which gives off water and binds the CO2 by forming a stable Calcium Carbonate.  When binding to other acidic gases, other calcium or sodium salts are formed. 

The primary constituents of soda lime include Calcium Hydroxide - Ca(OH)2 (about 70-80%), Water - H2O (about 16 to 20%), Sodium Hydroxide - NaOH (about 1-2%), and Potassium Hydroxide - KOH (about >0-1%).
 
Water is an important part of the reaction which takes place to bind the CO2 . The general description of the reaction is as follows: First the gaseous CO2 reacts with water to form carbonic acid - H2CO3. Then the NaOH reacts with the carbonic acid to produce Na2CO2 and H2O. The Na2CO2 reacts with the Ca(OH)2 which has been disassociated into Calcium and Hydroxide Ions. (Ca++ and OH-) to produce CaC02 (calcium carbonate, otherwise known as limestone.) The CO2 is now in a relatively stable state. There is a net production of three H2O molecules for every molecule of CO2 which is taken in.

Any help? I would empty out the water from the bottom of the scrubber and then reassemble it by putting the cartidge back in. Seal it by connecting up the hoses. NEVER repack a cartridge with partially used material.

[nigelH]

Originally Posted by Shaunzxr

Is it ok to do one 45minute dive every weekend for four weeks and then change the Slime?

Well if the last one was shallow (less than 20m) I'd do it.
Subject to the 140mins/20m 100mins/50m rules naturally as I'm a coward.

[Duncan Price]

Originally Posted by JB

Water is an important part of the reaction which takes place to bind the CO2 . The general description of the reaction is as follows: First the gaseous CO2 reacts with water to form carbonic acid - H2CO3. Then the NaOH reacts with the carbonic acid to produce Na2CO2 and H2O. The Na2CO2 reacts with the Ca(OH)2 which has been disassociated into Calcium and Hydroxide Ions. (Ca++ and OH-) to produce CaC02 (calcium carbonate, otherwise known as limestone.) The CO2 is now in a relatively stable state. There is a net production of three H2O molecules for every molecule of CO2 which is taken in.

actually its:

CO2 (g) + H2O (l) <=> H2CO3 (aq)

H2CO3 (aq) + 2 NaOH (aq) -> Na2CO3 (aq) + 2 H2O (l)

Na2CO3 (aq) + Ca(OH)2 (aq)-> 2NaOH (aq) + CaCO3 (s)

For every molecule of CO2 one molecule of water is liberated. Dissolution of CO2 in water to produce carbonic acid is reversible but is the start of the process. Without water the reaction would not take place efficiently. The sodium (and you can substitute potassium as well) hydroxide is regenerated.

The reason that the scrubber accumulates moisture is not just because of the water vapour exhaled by the diver and from any leaks in the system but also from the scrubbing reaction itself.

Before anyone suggests it I don't think that you could use moisture level as a scrubber monitor.

Trust me: I'm a scientist.

[BJ]

Originally Posted by Duncan Price

actually its:

CO2 (g) + H2O (l) <=> H2CO3 (aq)

H2CO3 (aq) + 2 NaOH (aq) -> Na2CO3 (aq) + 2 H2O (l)

2NaCO3 (aq) + Ca(OH)2 (aq)-> 2NaOH (l) + CaCO3 (s)

For every molecule of CO2 one molecule of water is liberated. Dissolution of CO2 in water to produce carbonic acid is reversible but is the start of the process. Without water the reaction would not take place efficiently. The sodium (and you can substitute potassium as well) hydroxide is regenerated.

The reason that the scrubber accumulates moisture is not just because of the water vapour exhaled by the diver and from any leaks in the system but also from the scrubbing reaction itself.

Before anyone suggests it I don't think that you could use moisture level as a scrubber monitor.

Trust me: I'm a scientist.

I am not a scientist but I know how to cut and paste from the molecular Products web-site!

All the best!

[Phoenix]

Originally Posted by Mark Chase

<snip>
I don’t like the look of all those solid lumps that come out,
</snip>

ATB

Mark Chase

Do you normally see a lot of solid lumps? bear in mind that I am a newbie to the YBOD but having emptied my scrubber canister out after a 129 min dive time (60m with 40min bottom) I found only one "lump" which was about gobstopper size. I would have gone on to use this canister for 1 20m or less dive had it not been for getting concerned over this thread.

Ian

[jptaylor9]

Originally Posted by schford

IMHO Potentially dodgy - as that scrubber material will be cleaning the CO2 from the air when it is open and exposed ....

Just out of interest, what mechanism is forcing air from the atmosphere thru the scrubber? When in the loop, some "lung power" is required to achieve this.

JT