Alternative condenser.

[Jolly John]

I take no credit for thinking up this design, I found it years ago on the web, but it seems to have disappeared. I used it for for about five years on my old still, and it was extremely efficient, I am making one for my new 'Boka'. It uses readily available copper fittings, and can be scaled up or down to suit you requirements. I find making coil condensers difficult, using standard pipe, and annealed pipe is expensive, this is lot easier to construct, well, for me anyway. The 'jacket' and 'cold finger' are piped in series.

I will post some photos soon.

[pounsfos]

hey that looks pretty cool!!

I would love to see photos, as for efficiency, we wind coils for the surface area, I dunno how this will perform, but I'm sure it will be fine

[bellybuster]

A cold finger inside a Liebig, cool. How long do you think it needs to be to knock down everything?

[Jolly John]

Thanks. As I say, I've used one for a few years on my old "cactus head" still, worked really well. I made one for a friend, he's doing fine with it as also. There is less resistance through this system, so you can can pump as much or as little as you need through it. I think it's efficiency is down to the fact that you're cooling the outside of the column, as well as the cold finger. I was certainly able to fractionate at a higher level than with a coil, but I didn't have a double coil. I'm not saying it's any better than a well made coil, but for me. an easier option.

[Jolly John]

A cold finger inside a Liebig, cool. How long do you think it needs to be to knock down everything?

I'll give some dimensions when I post the photos, will be a couple of days.

[rad14701]

I'm fairly certain at least one member here has built a concentric pot/reflux head with a cold finger added into it... I run straight concentric pot/reflux heads with structured packing in the top 1/3... No cold finger required... They are very efficient... I have a topic which covers how to make them without the pricy fittings...

[just sayin]

Thanks for your post. Great one, Jolly John! Just love good design and especially when it is in pretty, pretty copper

I am cursed with having try to maximize efficiency in materials, cost and effort. Yours is a nice simple build and it could be much less expensive with the techniques in Rad's thread.

On the efficiency front: an open spiral of appropriately sized copper wire around the cold finger would keep it centered, introduce turbidity and increase surface area. If you are already using wire turbulators between the walls of the Liebig and of the cold finger, make sure the one on the cold figure is counter-wound for max-efficiency…..just my 2 cents..............Just Sayin'

[Jolly John]

The two 54-42 reducers, 28-22-15 "T" and the 28mm stop end cost me £13.00 all in, I'm happy with that.
The 15mm stubs on the 54mm section, are soldered into holes, drilled after the reducers have been soldered onto the 54mm section. The assembly is then slid onto the column, and soldered.

Rad, can you supply a link to your topic?

[Jolly John]

Here are a couple of photos as promised. The helix on the cold finger is 6mm tube. Not sure if it will have any beneficial effect on efficiency, its there mainly to centralise the cold finger in the column.

The still is pretty much finished now, just got to sort out a cooling system.

the Leibig section is 140mm long (input tube to output tube), cold finger is 210mm long (28mm section).

As soon as I to the spirit cleaning run, I'll be able to give you some idea of efficiency, and reflux rate.