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RE: [new_distillers] Re: [Distillers] Vapor management versus reflux control

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  • Johan
    Johan, Let s consider this still as a normal reflux still and a vapour management arm is added on the other side. While the still is stabilizing and the heads
    Message 1 of 53 , Dec 1, 2003
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      Johan,

      Let's consider this still as a normal reflux still and a vapour
      management arm is added on the other side.

      While the still is stabilizing and the heads are collected, we keep
      the gate valve towards the distillate condensor well closed.

      Only after the heads are removed, this gate valve is opened and
      basically untainted ethanol is collected.

      Yes, the heads can taint the reflux condensor, but they also taint
      the scrubbers. I think that the most important issue is to consider
      that a separate collection valve under the main (reflux) condensor can
      remove the bulk of those heads and eventually later on, if one would
      wish, ethanol and tails.

      Now, I haven't done this in practice, but I can easily imagine that,
      doing so, will result in a less tainted product. Must be. The
      distillate condensor is only used when desired. This can be be for
      very clean alcohol, when one uses a high column or a high reflux rate.

      Of course, if the heads cannot not be bled off somewhere else, they
      are bound to condense in the distillate condensor and taint it.

      Regards,
      Dirk

      ___________________________
      Or something like this (almost as you said but with packing also)
      Column with packing, lm valve, 20 cm packing, lm valve, condenser

      Bleed of head at the top valve to begin with, then open bottom head,
      this valve shouldn't be tainted by now, lets say we use reflux ratio 10
      on that.
      If there is any remaining head in the vapour from the boiler, about one
      tenth of the amount will be removed through that valve, remaining will
      go up through the remaining packing and condense at the top, this valve
      can be set to bleed off head slowly (or be closed and opened once in a
      while). Maybe make a head that have rather much hold up of liquid to act
      like a buffer. The tainted alcohol will run back through the top 20 cm
      packing that can strip off head back to the top (some will come back
      down to bottom valve but the amount is greatly reduced).

      I tested this with the continuous still and the quality is good. It
      isn't completely free from head (it can't be as head is fed continually)
      but there wasn't much present ( I used 30 cm of packing between the
      valves).

      If distilled directly from mash in a batch still I can imagine that this
      will improve quality. I don't know what it is that comes from mash but
      personally I think it sprits becomes a little yeasty like in odour, even
      if head is bleed off at the beginning. With a long column and a head
      removal thing quality is good if the reflux ratio is high.

      But I'm going to test something better, a side stripper that removes
      head continually (first a normal column and the alcohol from that is fed
      to a second column at the middle of the height, head goes to top,
      alcohol to bottom). First test was a failure because the stripper didn't
      get enough heat. I'm going to test this soon though with a better heat
      "stealer" as heat is taken from first column, just waiting for one
      copper cup. Basically it's for continuous stills but I think it'll work
      well enough even for batch if the boiler contains mash. With a little
      luck it might be able to remove that yeasty smell directly at the first
      run so quality is fine or at least be able to skip removal of head in
      the second run since this is done by itself. If the stripper is good
      enough, the bottom of the stripper should contain nothing but alcohol
      and never get tainted.

      Johan
    • Mike Nixon
      Shane Kirkman wrote: Subject: Re: [new_distillers] Re: [Distillers] Vapor management versus reflux control So would a cup or 2 of boiling water tipped down the
      Message 53 of 53 , Dec 9, 2003
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        Shane Kirkman wrote:
        Subject: Re: [new_distillers] Re: [Distillers] Vapor management versus
        reflux control

        So would a cup or 2 of boiling water tipped down the condenser tube after
        the heads are removed help remove the tainting?
        ===============
        Hi Shane,

        It might, although you usually need to give components a good scrubbing with
        detergent, or soak in some active cleanser, to really shift those
        contaminants.

        Frankly, I wouldn't worry about it. What we are talking about here is a
        tiny amount of additional purification which is probably only worth
        bothering about if you are after ultra pure ethanol for use with scents or
        essences. In that case it is then probably better to go the 'dedicated
        path' way and try to keep as much of the heads away from your main product
        collection path.

        Just shows how far we have all come on this list (which was supposed to be
        for newbies!) that we are now discussing removal of trace compounds! Just a
        couple of years ago it was "what the hell is distillation?" :-)

        Cheers!
        Mike N
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