How long can you expose a scrubber to air?

[Mobulai]

Not sure why people keep bringing this topic up over and over

Given the popular demand for more info and tests and data about this cluster of topics (reusing sorb); I’m opening up donations to build a SNORT machine

I was already planing to build one for a few months (almost a year actually), but it’s a pricey endeavor and each test run costs so I’m still saving for it; I’m open to running all sorts of test variations (to those interested and willing to supplement the consumables costs)
You wanna try the impact of repacking sorb? Sure; adding sawdust to it, why not — let’s get these questions answered once and for all
(Not sarcasm)

Personally the most Id do is reuse yesterdives sorb if both last and next dives are less than 90mins — in hot dry environment like Dahab; and the snort is intended for canister design verification (someday I wish to make my own)
But resources can be managed well by sharing

Whoever is intrigued and feels generous just write me

 

[inquis]

Sorb is constantly “degrading” if you think about it. Whether it’s in a dry unit, moist unit, or the tub.

"Constantly degrading" seems rather inaccurate. In the tub (once recapped), after the CO2 is converted, it stops degrading -- the reactants are no longer present. A closed canister is no different as it is also sealed (just with a bit more volume).

 

[Dave Whitlow]

No offense but these questions about leaving scrubber packed and leaving in unit for how long are kind of dumb. It’s like asking how long will it take for my Hershey’s bar to melt in the sun. There’s so many variables there is no way to actually study it and get a universal answer that correlates to conditions outside of the study conditions.
Think about it. As soon as you open a tub of sorb it’s exposed to air. It’s not like sorb lives in some magical vessel that keeps it fresh. Sorb is constantly “degrading” if you think about it. Whether it’s in a dry unit, moist unit, or the tub.
Not sure why people keep bringing this topic up over and over

Much of what you said is incorrect, and people probably keep bringing this up because they hear such statements and intuitably know it is wrong, so they seek better advice. Hershey bars are horrid anyway, and an awful example of something that can be pleasant!

Sofnolime is a stable chemical and, without environment changes, remains unchanged for years. That is how chemistry works, and the whole manufacture and distribution of Sofnolime relies on this stability. In a sealed environent there a few variables and, unlike oxygen sensors, Sofnolime does not degrade with the passage of time.

The chemicals in Sofnolime function in a high moisture environment because they rely on surface moisture to absorb CO2 and enable reaction to occur, and to remove CO2. If the lime is too dry this may not work as well, so keeping it moist is good. If the scubber is sealed then the moisture and surrounding gases reach an equilibrium and, without change, this is equilibrium is maintained for some time.

The tests in the paper showed this situation persisted for weeks. I have used an undistrubed scrubber from months ago and seen it behave the same as one from a few days ago.

 

[mr_v]

The findings of that report are what one would "expect"; leave it out for 28 days and the scrubber looses its effectiveness.


My normal process is to remove the two scrubbers from the Revo and leave them to dry for a couple or few hours, then put them in a sealed Tupperware plastic container (one per scrubber). If the dive was more than 2 hours or deep, one scrubber would be emptied, refilled and sealed in the container if the unit isn't rebuilt.

Not sure why you'd want to leave scrubbers to dry out and then put them into air tight containers. It is not necessary. If your sorb has that much moisture it is probably overused or flooded, so you need to discard it. Otherwise, you can put the scrubbers in sealed containers, trash bags, etc.

 

[mr_v]

"Constantly degrading" seems rather inaccurate. In the tub (once recapped), after the CO2 is converted, it stops degrading -- the reactants are no longer present. A closed canister is no different as it is also sealed (just with a bit more volume).

Yes, it is inaccurate. I am not sure why people say, as properly stored sorb is not like a battery that continues to degrade. You'd typically store chemicals, like the ones found in sorb, in airtight containers to prevent unnecessary reactions (preserve normality).