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Re: have plenty of head for christmas

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  • Mike
    ... book ... Not a lot Brian. The column is barely long enough to establish equilibrium and I suspect, as he doesn t mention it, the column isn t insulated as
    Message 1 of 3 , Nov 21, 1999
      >mike in new zealand what do you think of the comment in the gert strand
      book
      >either page 22 or 32 about the short condenser,iv'e always used very long
      >units with slow counter flow to ofset thermal shock


      Not a lot Brian. The column is barely long enough to establish equilibrium
      and I suspect, as he doesn't mention it, the column isn't insulated as it
      should be (the best laboratory columns and top ends are built like thermos
      flasks with the working bits enclosed in a nice cosy vacuum jacket). I'm
      not surprised he loses so much heat that he finds 60cm as much as he can
      handle. I also cannot understand how this idea for inducing early reflux by
      shoving cooling tubes through the bottom part of the column got a foothold,
      yet we see a lot of columns with this odd feature now. All it does in
      ensure that you don't get good separation. It makes for a very good pot
      still, but doesn't this defeat the idea of having a column? Effective
      separation takes elbow room and quite a bit of time for the bits and pieces
      to decide which side of the fence they want to be. It's a bit like a sports
      tournament where time and a lot of intermediate races are needed to weed out
      the top performers. It can't be either cramped or hurried. If anyone
      thinks you can get good separation in the first few cm of a column they had
      better go back to the drawing board. Nature don't act thataway. She's a
      lady and needs persuasion - and quite right too! Having said all that, Gert
      is a thoroughly nice guy and produces a terrific range of excellent
      essences. I'm sure that Ray will support me in confirming that I too am a
      thoroughly Nice Guy who would never, ever dream of flaming anyone!!!

      All the best,
      Mike
      Still attired tastefully in sackcloth and ashes
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