Multiple columns

[H12rpo]

Anyone run a multiple column gig?


Just curious.

[Myles]

Nope but some folks have. Googe springs to mind.
Also commercially - https://www.stilldragon.org/discussion/544/help-8-column-with-10-plates-is-too-tall#latest

The usual method is a gravity feed from the base of each column back to below the liquid level in the boiler.

[H12rpo]

Thanks Myles, bu5 I’m thinking more of the double column set up which increases the product and decreases the time a la two or three columns coming off the top of the boiler as mentioned in the compleat distiller page 136 (cant copy and paste for some reason)

[Myles]

Hi H12rpo sorry for the miss-understanding.

You can do that but then you need to manage two columns. It is often much easier to increase the tube diameter and just deal with a single column.

Just for information - looking at the internal cross sectional area, as this determines throughput and eventually product speed.

54 mm tube taken as a reference = 1
67 mm tube = 1.56
76 mm tube = 2 (so 1 x 76 mm tube is the same as 2 x 54 mm tubes)
108 mm tube = 4.14

These days I recommend that folks treat 76 mm tube as the default size for a home distillation packed column for use on a keg based boiler.

[H12rpo]

Great advice there Myles thanks.
Another question ........ if the column is attached to the keg with a 54mm flange (hole) and then immediately opens up to (joins onto) a column of 76mm does the 2 inch initial restriction cause any issues or would it still be a 78mm column to all intents ?

[Myles]

Honestly it makes no difference. Many folks run 4" columns on a 2" ferrule. All you need is a bit of space - usually a reducer - to allow the vapour to expand to the size of the column. Some of the commercial split column systems use a 2" pipe to feed vapour to 16" or 18" columns.

Typically they feed in the side of an empty section at the base of the column.

It is more of an issue about physical column stability and balance. You can balance a 4" column on a 2" entry into a keg just fine. The main reason for fitting a 4" or 6" ferrule to a smaller boiler is about ease of access for cleaning.