JJ CCR Scrubber Radial? vs Axial

[LanceRiley]

Hi what's the difference and whats the advantages?

 

[Asheron]

Good little read from shearwater

The CO2 Scrubber in a Diver’s Rebreather

 

[broncobowsher]

 

[Alwayslearning2dive]

Primary difference is airflow routes. Axial is drawn through the middle, saturates the sorb and is exchanged back to the inhale counterlung. Radial is drawn evenly around the outside of the scrubber, returning through the middle. Idea is that you have more surface area to exchange Co2 and it improves wob.
Specific to the JJ the radial will increase duration. The axial is much easier to pack than the radial.

Unless your profiles are multi hour, deep, medium effort, the axial should be more than enough.

 

[RedSix]

Specific to the JJ the radial will increase duration. The axial is much easier to pack than the radial.

Is this really true? Not sure about that, but doesn't JJ offer a axial scrubber as standard, a radial scrubber as option for the standard can and an extended range can and scrubber (which is radial, too)?
Does the radial scrubber for the standard can really increase duration? From my feeling I would say, since it uses more or less the same space, but has a tube in the center and hence the actual amount of sorb would be lower? Means the usable duration is decreased, but since the cross-section for gas travel is increased, the wob might be lower?

 

[Madddogggy]

Just comparing the normal canister scrubbers to one another:
The axial scrubber holds 2.3kg (THE JJ-CCR REBREATHER – JJ-CCR VERSATILE REBREATHER).
The radial scrubber holds 3kg (JJ-CCR Radial Scrubber).

Thus in theory, the radial scrubber's extra 0.7kg allows for an extended scrubber duration when compared with the axial scrubber. Also, the distance the exhaled breath needs to travel to before it enters the inhale side of the radial scrubber is less than the axial scrubber, reducing the WOB.

As far as purchasing, the radial scrubber, it is add-on. Someone will correct me here, but when purchasing the JJ-CCR from the factory, anything that is not part of the standard configuration, is an add-on.

 

[GF99/99]

Is this really true? Not sure about that, but doesn't JJ offer a axial scrubber as standard, a radial scrubber as option for the standard can and an extended range can and scrubber (which is radial, too)?
Does the radial scrubber for the standard can really increase duration? From my feeling I would say, since it uses more or less the same space, but has a tube in the center and hence the actual amount of sorb would be lower? Means the usable duration is decreased, but since the cross-section for gas travel is increased, the wob might be lower?

JJ comes standard with axial (2.3kg capacity CE rated 3hr) you can buy a plug and play radial (3kg capacity CE rated 4hr) and another option is to buy what JJ calls XRC (4 kg capacity) but this is a whole new can and radial scrubber.

Yes it is true JJ radial offers a longer scrubber duration, additionally yes a radial is a PIA to pack over the axial.

 

[BlueTrin]

Is this really true? Not sure about that, but doesn't JJ offer a axial scrubber as standard, a radial scrubber as option for the standard can and an extended range can and scrubber (which is radial, too)?
Does the radial scrubber for the standard can really increase duration? From my feeling I would say, since it uses more or less the same space, but has a tube in the center and hence the actual amount of sorb would be lower? Means the usable duration is decreased, but since the cross-section for gas travel is increased, the wob might be lower?

My JJ came with an axial, if you look at the manual and search for axial, it will say that radial is an option for the international edition.

https://jj-ccr.com/wp-content/uploads/2022/12/Version_300_DRAFT_ENG.pdf

 

[LanceRiley]

Primary difference is airflow routes. Axial is drawn through the middle, saturates the sorb and is exchanged back to the inhale counterlung. Radial is drawn evenly around the outside of the scrubber, returning through the middle. Idea is that you have more surface area to exchange Co2 and it improves wob.
Specific to the JJ the radial will increase duration. The axial is much easier to pack than the radial.

Unless your profiles are multi hour, deep, medium effort, the axial should be more than enough.

how do you define multi hour?

deep? how deep is deep? 80m? more? goal is to get to 110m for a wreck im after.

 

[LanceRiley]

so axial is standard. when the manual says 3hours.. is it really like 3 hrs the sorbs are useless? or it depends how one breathes?