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Question about why this vacuum setup works.

  1. Jul 8, 2011 #1
    So I'm degasing a solution in a glovebox. The way we did it is get a rubber septum that can cover the bottle opening. We stuck a needle through the top of it, as well as a glass tube with a porous end. We used the needle to create a vacuum in the bottle by hooking up it up to a pump. The glass tube is submerged in the solution, but is stuck through the rubber to be the only opening into the box. The argon from the glovebox then flows down the glass tube and out the frit at the bottom, degassing the solution.

    I can't figure out why the gas would be sucked down the tube. Sure there is a vacuum in the bottle, but the tube opening is submerged. It doesn't know or care that there is a vacuum above it. The only part of the glass tube that experiences vacuum is the long tube part without any openings. So how is the vacuum sitting above the liquid making the gas flow into the tube which has it's end submerged?

    Obviously it works for some reason, I just don't know why.

    This has been bugging me, thanks.
  2. jcsd
  3. Jul 8, 2011 #2


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    So this tube is stuck into the solution you want to degass which is in a box? And the tube is porous on both ends? Where is the bottle located? I'm trying to help but I am not familiar with this process.
  4. Jul 10, 2011 #3

    The bottle is in a glovebox, but I think the solution still had dissolved oxygen in it so I wanted to degas it with the argon in the box. The needle is stuck through the rubber septum which is sealing the bottle, and is connected to a vacuum line. The glass tube is also stuck through the septum, with an opening on each end (the end in the bottle is porous, but I don't think that matters).
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