Half-packing sorb -- Possible, or deadly?

[Wibble]

You want a Revo or Gemini where there are two scrubbers. When completing a dive of up to 3 hours, you simply remove the exhale scrubber, dump and refill, then swap the inhale scrubber to the vacated exhale scrubber and put the newly filled scrubber into the inhale side.

If diving for more than 3h, you refill both.

This means you only use 1.3kg/4lbs for up to 3h of diving, i.e. virtually all dives including deep deco dives.

BTW Revo make a large scrubber modification for longer runtimes. Allegedly they've only ever sold a handful of these, such is the low demand.

 

[Mobulai]

unless someone develops an (assumingly pretty complex) Iris mechanism for radial scrubbers to act as a spacer, it would be pretty impossible for radial scrubbers to not have gaps

Impact of such theoretical spacer on wob not withstanding

 

[jale]

Hi
For radial scrubber, the only way is to have different scrubber sizes like the Meg, the HH and others.
For axial, an early example is the Dolphin with an optional internal "grill" to reduce the scrubber volume. Some "tube RB" give you also the option of packing the volume of lime you want.

 

[AJ]

Can only comment on my experience with the JJ-CCR. What I do is fill for theoretically 3 hours worth of diving. I keep track of every easy dive I do and, depending on dive lenght, use the scrubber for max. 3 dives or 4 weeks. More dives or longer time, means throwing away the sofno, no matter if it's used or not.

On demanding dives like cave or deco I have a new fill every diving day. I found out in real life that theoretical 3 hours sometimes is less than 3 hours doing demanding dives. Beleive me, you don't want to find out in a cave or a deep wreck that the scrubber is gone.

 

[InWay2Deep]

Expanding on this, someone could only fill 1 canister of the sidewinder and do a 3hr dive no? or rotate exhale to inhale side and get 9hrs from 1.5 fills!

 

[davehicks]

Expanding on this, someone could only fill 1 canister of the sidewinder and do a 3hr dive no? or rotate exhale to inhale side and get 9hrs from 1.5 fills!

I dive the kiss spirit, the back mount predecessor of the sidewinder. It has two separate sorb canisters, inhale and exhale side. The Exhale side gets used first, and after 3 hours of diving the Inhale side is typically still 90% unused.

So Yes, you can rotate the Fully Filled canisters. My typical pattern is to do three hours of diving, dump the exhale side and refill. Rotate Inhale to Exhale, put the fresh canister on the Inhale side. Repeat. If I haven't dived in a month or so I will refresh everything, or if I plan dives that exceed recreational limits.

You definitely should NOT dive with only one canister filled. Having two canisters provides redundancy and protects against a possible breakthrough or water intrusion in one canister.

 

[211ratsbud]

Expanding on this, someone could only fill 1 canister of the sidewinder and do a 3hr dive no? or rotate exhale to inhale side and get 9hrs from 1.5 fills!

From discussion with other people knowledgeable about the subject, I would say the sidewinder is a poor candidate for this idea. The 2 issues that are would be of consideration are both dwell time and pulsatile flow In that particular scenario. Dwell has been mentioned above, and pulsatile flow has been studied by the Navy using an example breathing loop.

Edit: I misread the post so disregard my text above.

 

[Mobulai]

Expanding on this, someone could only fill 1 canister of the sidewinder and do a 3hr dive no? or rotate exhale to inhale side and get 9hrs from 1.5 fills!

I wanna say yes…
But afaik the stack time for a full fill (both cans) is 3.5hrs, but I could be wrong (still a noob)

 

[grantmac]

Being able to add additional volume ala Go does seem like an interesting concept rather than having to own multiple cans or short filling.

 

[rjack321]

I dive the kiss spirit, the back mount predecessor of the sidewinder. It has two separate sorb canisters, inhale and exhale side. The Exhale side gets used first, and after 3 hours of diving the Inhale side is typically still 90% unused.

You have no way to actually know this and it's dangerous to promulgate fallacies like this. Nevermind that scrubber duration is highly dependent on water temperature, and even if you were using indicating sorb you can't see the actual reaction front.