3 inch VM takeoff

[Holy McBuff]

Hi all, I was going to start a build thread for my still, but i've killed 3 bloody phones in less than 3 weeks :angry-banghead: well one wasn't killed but i really really hurt it... Anyway, i have a 1.6 meter 3 inch bottom section, and my top section it a 150 mm condensor with 5X1/2 inch tubes inside.. i'm pretty sure it will be enough, my question is with the take off.. i was planning just sticking a one inch pipe on the side through a 1 inch gate valve, but all the gate valves ive seen have almost the same size hole in the middle.. from half to a full inch the holes dont seem to vary by more than 2 or 3 mm.
I've read plenty of build threads on HD and they make such a big deal about the theory, but i cant seem to find out if the hole size matters, or the take off arm itself. Also, is it worth putting the take off arm through the still body with the bottom cut off to try to force vapour out to the valve, ( I'm not using reducers) or is there no need?
I'd upload pictures but yeah, i have no camera.. even the one on my laptop is fucked :/
Thanks in advance..

[Yummyrum]

If you only intend on using it for producing High ABV spirit then it will be fine . :handgestures-thumbupleft: Its only when you wish to take off quickly at low ABVs that the reduced size will become a problem .


Boring theory bit :geek:
To validate that in theory.....to get High ABV you need to have a high reflux ratio .In a VM ,this means the aperture size ( IE the opening created by the valve ) needs to be small compared to the diameter of the column .
This means that you only take off a small proportrion of the vapour , ....the rest goes up to the Reflux condenser and returns to the packing to aid prification.

When you want to strip , then you need ideally no reflux....this is where a VM fails to deliver as even if you had an aperture equal to the column diameter ( which is why you see all the dual reducer VMs with an "equal Tee " fitted , then you still only get 1 part of the vapour out and the other part is refluxed

[Holy McBuff]

Heh... everything i have read so far actually makes a bit more sense now.. funny how that happens, thanks Yummy... i do have some spare 2 inch, and a heap of half inch stainless in 10 meter coils from some glycol coolers i got from a pub a few years ago.. i was thinking of making a stripper with a massive worm, i reckon it just might work :-D
I'll take some photos when i can, but it's really very basic.. Thanks :D