2" or 3" Column

[newerbrewer]

OK so here is my dillema. I have bought a couple of stills but am not very happy with the design on either of them and am now set to make one of my own following bokokobs dual slant plate. Basically one long column with a 'double helix' at the top and 2 slanted plates directly under... One that leads to a valve. I have some scetches and my material list drawn out and am deciding if I should go for a 2" column or 3". I think I can get either for a fair price from a local scrap yard and am wondering what the advantage of 3" over 2" is, and if it is a good idea if I can afford it, or simply overkill for a home project. I am pretty new to the game and could use some advice. Also, what is the ideal length (height) for the column? I am thinking 48". Is there any benefit to going higher?

[decoy]

it has a lot to do with the size of your boiler and how fast you want to take off at

There is no need to use any more the 2" or 50mm tube upto a 100L boiler.

[newerbrewer]

I am using a keg for a boiler so I guess a 3" column would be overkill then. Would a 2" column, 48 inches tall be an optimal setup? I've seen a few threads stating an optimal mix of diameter to height is 1" to 24".

[HookLine]

Main advantage of a 3" column is that the output rate is about twice that of a 2". When I do a reflux run with my 2" column and a 40 litre still charge at 40% abv, I basically set aside most of a weekend to cover everything including setting up, pulling apart and cleaning up.

Main disadvantages are that the costs for 3" are higher, and it is a fair bit heavier than a 2", so you need to make sure the boiler is sturdy and stable enough to handle it.

If I was building a new column I would probably go for 3" if I could afford it.

Bottom line, either is fine.

[newerbrewer]

Thanks hookline for the reply. Time is more or less a premium for me these dayls, also would like to build a still that will suit my needs for the next 25 years and I really do believe in buying/building the best and only doing it once. I still haven't got pricing from my local scrap yard on 2" vs 3". If there isn't too much of a difference in price, I will likely go for the 3". If I do go 3" instead of 2", should I make a taller column as well or do you think 48" would be sufficient? Thanks again for all your advice.

[newerbrewer]

Also, where would a guy find 3" copper couplings and cap? Is there a place online I could buy it from? Thanks,

C

[newerbrewer]

Found 3" copper coupling online here:

http://www.plumbingsupply.com/copper.html#coupling" onclick="window.open(this.href);return false;" rel="nofollow

Holly crap, $30 for 3" vs 9 for 2". I'll stick with the 2 .

[rad14701]

You found out quick, newerbrewer... The pricing jumps way up real quick with copper sizing...

also would like to build a still that will suit my needs for the next 25 years and I really do believe in buying/building the best and only doing it once.

You're only convincing/fooling yourself with that statement... The majority of us here know better... Only build one still...??? Hah...!!!

[decoy]

unless you a planning on producing 100's of Litres of spirit per year the overheads increase with the speed of take off..

to give you an idea of approx running time and performance of a 50L still with a 2" column using a sugar wash 15-18% abv
50L strip run configured as a pot still with preperation and preeheating of next batch of wash with with condensate less then 4hrs

50L 50% abv low wine spirit run with 2" reflux column 6-8hrs, producing 15-20 Litres 92-96% abv

if you increase the take off you have to increase cooling, power/gas and you have found out the price of copper fittings also the copper packing and a larger boiler to make it effective.

it is not worth the extra costs and overheads to use 3" on a 50L boiler.

[newerbrewer]

And that my friends... is why I am a member of this board... all the great advice. Thanks so much for helping me find the right path. I'm settled on 2".

Cheers.