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  1. #1

    Default CCRs to be obsolete?



  2. #2
    Administrator Forum Admin
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    Default

    That reminds me of a novel on the same subject. It was called "The Caves of Karst" by Lee Hoffman 1969. It talked about rebreathers, and cave divers with gills.

    Forrest Wilson (with 2 Rs)
    Any opinions are personal.
    Sump Divers

  3. #3

    Default

    if CCRs become obsolete...what does that make my rb80?


  4. #4

    Default

    Quote Originally Posted by LiteHedded View Post
    if CCRs become obsolete...what does that make my rb80?
    LOL.

    Huge?


  5. #5

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    Quote Originally Posted by Ben M View Post
    LOL.

    Huge?
    FALSE.


  6. #6
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    Default

    Don't worry, the side effects of the gill implantation procedure are mild.



    "I looked up my family tree and found out I was the sap"
    "I told my psychiatrist that everyone hates me. He said I was being ridiculous - everyone hasn't met me yet."
    "Yeah, I know I'm ugly... I said to a bartender, 'Make me a zombie.' He said 'God beat me to it."
    "I went to a fight the other night, and a hockey game broke out."
    "I came from a real tough neighborhood. I put my hand in some cement and felt another hand."

    Rodney Dangerfield 10-5-2004

    "Into the blue again; in the silent water
    Under the rocks, and stones; there is water underground" Talking Heads

  7. #7

    Default

    Quote Originally Posted by LiteHedded View Post
    FALSE.
    Only kidding. The unit itself actually isn't that large.

    I love how they show photos of a "visual" prototype and then say it would require 344 sq ft of surface area but the one they show probably has less than 5 sq ft of surface area.


  8. #8

    Default

    It's worth noting that this "concept" was developed by an arts major in collaboration with a design studio, not a science / engineering department or medical school. That tells me all I need to know about how realistic this really is.


  9. #9

    Default

    For the fun of it, here are the numbers: assume a diver with a sac rate of 0.5 cfm, at a depth of 33ft. He would need 28 liter of air, or 3.5 liters of oxygen per minute. That's about 8g per minute, or 130mg per second. Typical ocean water (I couldn't find numbers for cave water quickly) has, somewhat dependent on temperature and depth, about 10mg of dissolved oxygen per liter. So the gills would have to pump through 13 liters, or 3.4 gallons of water each second, and extract all oxygen completely, to support even such a benign dive. This will take a rather big pump, depending on the back pressure in the gills it would be something like 5hp. That's just a little under 4kW. On a big scooter battery, that would give you a runtime of maybe 15 minutes. But you could use the water jets coming out of the gills for propulsion and wouldn't need an extra scooter. I wonder why CNN didn't bother running these numbers before giving this airtime. But then, it's in their "style" section, not science and technology.


  10. #10

    Default

    Quote Originally Posted by Kafkaland View Post
    For the fun of it, here are the numbers: assume a diver with a sac rate of 0.5 cfm, at a depth of 33ft. He would need 28 liter of air, or 3.5 liters of oxygen per minute.
    I'm not a CCR diver but I do know that oxygen consumption (metabolism) is not effected by depth and the entire o2 contents of that .5 scfm is not consumed. Some of it is exhaled.

    A quick google search suggests that actual o2 consumption is more around 1 - 1.5 lpm of O2. Feel free to redo your calculations based on that as I didn't really follow the rest of the math.



 

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