+ Reply to Thread
Page 3 of 5 FirstFirst 1 2 3 4 5 LastLast
Results 21 to 30 of 42

Thread: Activating the sorb on a CCR Bail out Rebreather

  1. #21
    RBW Member Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike's Avatar
    Join Date
    Feb 2005
    Location
    tokyo
    Posts
    4,504

    Re: Activating the sorb on a CCR Bail out Rebreather

    Quote Originally Posted by jcook  View Original Post
    All the guys who use CCR bail out breathers,

    How do you get the sorb activated in the canister besides constantly swapping between loops every few min? (way too much task loading if you ask me, and just asking for an accident) Do you run it as an SCR for a few min while the sorb activates and then run it as a CCR after that?

    in my experience swapping loops is dangerous (can lead to flood or mistake) and unecessary in warm water.


    I dont pre breathe or swap during the dive. I run semiclosed for a while if I bail. Gives time for scrubber to heat up. Ive test bailed a bunch of time shallowish (70m) and one bail at 150m and it apears to work but I dont have a lot more than that to back it up. YMMV

  2. #22
    RBW Member Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike's Avatar
    Join Date
    Feb 2005
    Location
    tokyo
    Posts
    4,504

    Re: Activating the sorb on a CCR Bail out Rebreather

    Quote Originally Posted by sea2summit  View Original Post

    And yes I'm sure 5 min of pre breath at the surface is more than enough time for CO2 issues to manifest themselves.

    Wrong.

  3. #23
    RBW Member Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike's Avatar
    Join Date
    Feb 2005
    Location
    tokyo
    Posts
    4,504

    Re: Activating the sorb on a CCR Bail out Rebreather

    Quote Originally Posted by gallathan  View Original Post
    Actually, I think the task loading is worth it. Yes, the sorb should be almost immediately active, BUT, there's a tremendous psychological comfort in KNOWING your BOB will work immediately. LOTS of issues with early bobs flooding on descent, and also, you often have to breathe the loop of the bob to move gas round the loop/ensure a good mix of the gas in the bob...

    this is very true and why i do take a few breaths from the bob at times during the dive (most usually at least when I hit max depth, turn point or last stage tank) - but this is not in an attempt to keep scrubber active is an attempt to verify it hasnt flooded to give me the pieve of mind your talking about (which is nice to have on a high stress dive)

  4. #24
    RBW Member Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike has a reputation beyond repute Drmike's Avatar
    Join Date
    Feb 2005
    Location
    tokyo
    Posts
    4,504

    Re: Activating the sorb on a CCR Bail out Rebreather

    Quote Originally Posted by paulraymaekers  View Original Post
    my God....

    have you ever done any testing on sorb? in a lab, in practice?
    so don't spread such nonsense!


    put a breather with good sorb in the ansti machine, at 40m depth, water at 4° celcius, let the system cool down completely, breath the unit cold (no CO2 injection) for 10 minutes
    then inject 1.6 l/m STPD CO2 in the unit, and see what comes out at the end of the scrubber:

    NOTHING, ZERO, NADA

    no CO2 at all: the scrubber works from the very first breath!

    and now tell me about your testing, and how you found the opposite result!

    paul

    Paul, did you test a cold scrubber starting perfomance deeper, at the sort of depths a bob might be called into action and at the kind of flowrates a stressed diver may be producing?

    I wonder if expecting no initial co2 spike out of a cold scrubber at say 150m depth (water may not be as warm there as on the surface) may be asking a bit much. In addition breathing rates and co2 production would likley be high at time of bail. Which is why my protocal is to try to run scr at first (if possible)
    Last edited by Drmike; 28th June 2010 at 01:23.

  5. #25
    Doing What Works jcook is an unknown quantity at this point jcook's Avatar
    Join Date
    Nov 2008
    Location
    GA
    Posts
    361
    Sidemount Meg

    Re: Activating the sorb on a CCR Bail out Rebreather

    Thanks for the answer Dr. Mike!

  6. #26
    rEvo's daddy
    paulraymaekers has a reputation beyond repute paulraymaekers has a reputation beyond repute paulraymaekers has a reputation beyond repute paulraymaekers has a reputation beyond repute paulraymaekers has a reputation beyond repute paulraymaekers has a reputation beyond repute paulraymaekers has a reputation beyond repute paulraymaekers has a reputation beyond repute paulraymaekers has a reputation beyond repute paulraymaekers has a reputation beyond repute paulraymaekers has a reputation beyond repute paulraymaekers's Avatar
    Join Date
    May 2005
    Location
    belgium
    Posts
    4,073
    rEvo

    Re: Activating the sorb on a CCR Bail out Rebreather

    Quote Originally Posted by Drmike  View Original Post
    Paul, did you test a cold scrubber starting perfomance deeper, at the sort of depths a bob might be called into action and at the kind of flowrates a stressed diver may be producing?

    I wonder if expecting no initial co2 spike out of a cold scrubber at say 150m depth (water may not be as warm there as on the surface) may be asking a bit much. In addition breathing rates and co2 production would likley be high at time of bail. Which is why my protocal is to try to run scr at first (if possible)
    no, did not yet test an immediate cold start deeper then 40..
    will do that later, but my machine only goes till 100m :-(

    but from my experience in testing sorb till 80m, it looks like there is a huge difference between 'high performance' and 'low performance' sorb

    my 'expectation' is that, say for temp > 10°, a decent scrubber with >2.5kg high performance sorb, will start from the first breath at 100m depth, even at higher CO² production

    paul
    www.rEvo-rebreathers.com
    ...."Yes you have to pre-breathe to activate the scrubber sorb, anyone who says different doesn't know what they are talking about!"...
    .... to get more accurate CO2 injection in the breathing machine we put 2 mass flow controllers in series ...
    .... The noise is a few tens of nano-volts, so DL were able to reduce the output voltage ...
    .... radial scrubbers give longer dwell time than axials...
    .... the earth is flat and ...

  7. #27
    All IMVHO obviously... Ben Field has a reputation beyond repute Ben Field has a reputation beyond repute Ben Field has a reputation beyond repute Ben Field has a reputation beyond repute Ben Field has a reputation beyond repute Ben Field has a reputation beyond repute Ben Field has a reputation beyond repute Ben Field has a reputation beyond repute Ben Field has a reputation beyond repute Ben Field has a reputation beyond repute Ben Field has a reputation beyond repute Ben Field's Avatar
    Join Date
    Aug 2005
    Location
    Weymouth, England
    Posts
    3,023
    NVMCCR Inspiration

    Classic KISS, Sport KISS

    Re: Activating the sorb on a CCR Bail out Rebreather

    (Had this random idea a few months ago but forgot about it till reading this thread)

    Now take this with a pinch of salt because its complete nonsense and would require a whole new unit of some sort from sratch.

    So- deep divers want Bail out rebreather rather than bail out tanks understandable but as many have observed, difficult to bring the BO Rebreather to the point in the dive where its needed and uncertainty of its function when needed.

    Thinking back to OC, diving a rebreather is like diving on a single tank, diving a rebreather with bailout a bailout rebreather is like diving a Single tank with a Pony bottle (questionable use in emergancy) what is needed for you deep nutters it a rebreather configuration like a Manifolded Twin Tank rig.

    Two rebreathers, that you dive from the surface, both working, tested, and functional at all times throughout the dive with independance but for the shared loop gas and then should one fail an Isolation Valve can be turned and the pair seperated (ala- OC Shutdown drill) and the diver stays on the working unit.

    Yes- loop flood comprises both... or does it, most recent units and flood tolerant/clearable and once isolated the working/non-leaky side can be cleared and used while the other side is left to cocktail itself.

    Clearly miles away mechanically and SOP wise from what we do right now but maybe an idea for someone with time to kill? (Paul- your unit already has two scrubbers, perhaps your well placed to do abit of plumbing and see if this would work- could you suddenly switch to one scrubber and live to tell the tale?)

    Just an idea...

  8. #28

    Re: Activating the sorb on a CCR Bail out Rebreather

    Quote Originally Posted by Ben Field  View Original Post
    what is needed for you deep nutters it a rebreather configuration like a Manifolded Twin Tank rig.

    Yes- loop flood comprises both... or does it, most recent units and flood tolerant/clearable and once isolated the working/non-leaky side can be cleared and used while the other side is left to cocktail itself.

    Just an idea...
    if you could get them separable (i.e one would not adversely effect the other - flood ) & then you would revolutionize how long/deep dives are done.

  9. #29
    RBW Member Iain third will become famous soon enough Iain third will become famous soon enough Iain third will become famous soon enough Iain third will become famous soon enough Iain third's Avatar
    Join Date
    Oct 2008
    Location
    Sydney
    Posts
    117
    Classic Inspiration

    Re: Activating the sorb on a CCR Bail out Rebreather

    Quote Originally Posted by Ben Field  View Original Post
    Two rebreathers, that you dive from the surface, both working, tested, and functional at all times throughout the dive with independance but for the shared loop gas and then should one fail an Isolation Valve can be turned and the pair seperated (ala- OC Shutdown drill) and the diver stays on the working unit.
    Some people have done that, it looks pretty bulky. Also quite confusing with two sets of cells, etc, I imagine you quite quite easily forget which loop is which.

    http://www.rebreatherworld.com/showthread.php?t=33427


  10. #30
    Doing What Works jcook is an unknown quantity at this point jcook's Avatar
    Join Date
    Nov 2008
    Location
    GA
    Posts
    361
    Sidemount Meg

    Re: Activating the sorb on a CCR Bail out Rebreather

    I think Bill Stone had built some of his CIS Lunars MK-5's into double units for the Wakulla Springs surveys. From what I heard, each scrubber could be used in either loop. Someone chime in if I am wrong on this one.

    But my original question was just one of a completely stand alone BOB, that other stuff sounds way too expensive.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts