Re: vapour speed
- --- In Distillers@yahoogroups.com, "watertrade2003" <james1@w...>
> Hi all,for
> I hope everyone had a fun and safe Christmas! I'm just waiting
> life to go back to normal. I went to buy some plumbing fittings forthe
> my new still just to find everyone still on holiday! Bah Humbug!
> Anyway I was thinking How do you calculate the speed at which
> vapour is traveling up a column? I imagine you would work out how
> much vapour is been produced per second ( with power input) find
> volume it occupies find the volume of the column divide volumeof
> vapour by the column volume and that would give you the speed ?You got it right.
> which leads to my next question how long does the vapour need to bea
> in contact with the packing to get one separation/plate? - using
> standard calculable packing e.g. Marbles/ structured copper mesh etcthe
> There are probably hundreds of things I'm not taking into
> consideration but a rough guide would be good enough to work out
> dimensions and power settings for my next stillWell, I've been using plain vaporspeed as an indicator of how well it
> Can anyone help shed some more light on this??
works. According to M. Nixon vaporspeed should be kept below 20"/s,
in practise you'll enter flooding/choking soon after that. As an
example PDA-1 is recommended to use 12"/s and I use 5"/s (30cm long)
in my spiral/column still. Packing in these assumptions is scrubbers
or mesh. One thing you need to take into account is power losses
before any vapor enters the column, it's quite easy to loose over
500W through uninsulated boiler.