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Thread: Oval scrubber designs

  1. #11
    Draeger alexander.busch_st is an unknown quantity at this point alexander.busch_st's Avatar
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    LAR, Dolphin, Evolution

    Re: Oval scrubber designs

    Nice work! How about a water trap feature on the entrance to the space containing the sorb (right side of your drawing)? I would asssume some condensation in the gas flowing through your outer wall. Ideally that water stays away from the sorb.
    What is the desired orientation in the rig? As sketched?

  2. #12
    RBW Member rian is an unknown quantity at this point rian's Avatar
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    Re: Oval scrubber designs

    Unless your using a solid state scrubber media aka Micropore Extendair, not sure how simply having two separate axial scrubbers will "eliminate" the risk of channelling as you can still get that in either or both....




    Thanks a lot for the positive comments. More thanks for the links !

    I agree the word “eliminate” were the wrong choice................ but 2 independent scrubbers in series will reduce the chance of a breakthrough dramatically.
    The Infinito is truly a magnificent design, but this is the first time I see it. I take my hat off for the designer whom must have explained his concept to another person to actually draw and machine the component. For me there is no challenge in copying somebody else’s idea. This I can say in all honesty, is my own design and I’m going to build it in my own garage over the next few years.................... The moulds for the head, scrubber canisters and body of the machine will be done by more competent people with nice machines .

    As I understand it, if you increase the loop volume you reduce the velocity of the gas during a breathing cycle thus reducing the pressure drop across the bed of sorb. The bigger volume also helps to increase the dwell time of the CO2 reach gas with the sorb thus increasing the contact time. The loop volume on the exhale side (dangerous gas) is as low as possible. I will reduce the size of the second chamber if I can come up with a better idea for sure. The volume between the two scrubbers is big enough, should channelling take place on the bottom scrubber, to normalise the gas concentrations before it enters the second scrubber. The down side of the increased volume is that you need to add more weight to the system. Luckily I managed to keep the volume of the head as low as possible. I believe the machine will be balanced quite nicely at the end.
    Alexander to answer your question/concern. The drawing needs to be turned 90⁰ clock wise and that will then be the position on your back. There is ample space in the bottom between the scrubber and outer housing to slide a tampon in to absorb the moisture during extended dives.

  3. #13
    Draeger alexander.busch_st is an unknown quantity at this point alexander.busch_st's Avatar
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    Re: Oval scrubber designs

    Quote Originally Posted by rian  View Original Post
    As I understand it, if you increase the loop volume you reduce the velocity of the gas during a breathing cycle thus reducing the pressure drop across the bed of sorb. The bigger volume also helps to increase the dwell time of the CO2 reach gas with the sorb thus increasing the contact time.
    Gas velocity is actually not really dependent on overall loop volume:
    • Gas velocity in the scrubber essentially does depend on effective x-sectional area of the scrubber, the bigger the better.
    • Gas velocity in the scrubber should decrease if both an inhalation and exhalation counterlung are used since they act as buffer volume.
    Imagine a scuba cylinder, you can increase the cylinders volume (and by that overall system volume) as much as you like but the flow (and its velocity) through the valve only depends on the valve idealized (--> nozzle) x-sectional area (assuming constant pressure).

    Best, alex

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