Spiral stills

[johnny108]

Do any mentors have any experience with the "spiral still"?
It would seem to be usefull as a stripping still you run in a corner, while you pay a bit more attention to a final run, on another still.
Rather than just a long line of "your kidding" or "really, you should upgrade" posts- I'm actually curious if anyone with experience has actually built one, and what were the results.

[rad14701]

Really...??? Are you serious...??? Couldn't help that...

Yes, it's been discussed... I took the time to do a site search {hint} because I knew myles had done some experimenting... Look HERE... There is probably more information if you take the time to look further...

And now for the warning... Using a slow working spiral still like those depicted elsewhere on the internet in no way means you should ever leave it unattended...

[junkyard dawg]

whats a spiral still?

can't poke fun at it if I don't know what it is

[Husker]

No rad, this is the spiral still. I HATE giving a link to a very shoddy site, so I will NOT provide a clickable link. I do NOT want google to have any links from HD to this POS.

This thing is gen-2 of the bucket still.

http://www.bryggforum.nu/wiki/wiki/upload/The_Spiral_still.pdf

[junkyard dawg]

I found that one too...

What a piece of junk.

Why would someone build this? What problem would this solve? I think I'd dive into freeze 'distillation' before I got into that...

[rad14701]

Husker, you should know I never would have linked to those pathetic plastic stills with spirals...

But there are other discussions than the one I linked to - somewhere...

[Husker]

But there are other discussions than the one I linked to - somewhere...

Yes, but when you hear discussion and questions about 'the spiral still' that is the one they are talking about. It is like the dorm room special. As bad as that 'easy still' or whatever, that gert strand sells, or sells instructions on how to build.

H.

[johnny108]

My intention wasn't a direct copy- more of an investigation into how well it operates; A high-proof pot still? A weak reflux, etc?
I have NO intention of using anything but stainless steel and copper, if I build one.
Yes- I know it can't be left unsupervised, however, it also doesn't require the "buddhist monk staring at a candle flame" level of concentration, either- which is how I usually do a run.....

[Braz]

A high-proof pot still? A weak reflux, etc?

Yeh, probably. You'd likely get some reflux from the air cooling of the "uphill" coils. The amount of reflux would be hard to calculate and likely would gradually change (reduce) as the run progresses and the coil heats up. Not to mention the effect of different ambient temps. I can't see any reason to build something like this, even if you did use all copper/stainless. It just seems it would be a nightmare to try to get repeatable performance out of it.

[Prairiepiss]

From the reports I have read about stills like this. The output is more like a half assed pot still run. Like a stripping run that takes 2 or 3 times longer. If its the type of still I'm thinking of? Now the one Myles built is a different story. So if you built something closer to what Myles did and ran it like he did it mite work. But it would be much like running a pot still. So why not just build a pot still? I could be way off. But you haven't really described your intended still plans?

[myles]

A spiral still is a valid tool. Lets be clear though - I am not talking about the plastic bucket type - I don't favour them. However, on a conventional boiler it is an air cooled device. It has an air cooled reflux column and an air cooled condenser. Obviously there are limmitations, but if you are stranded in the desert one of these will keep you alive.

For our more conventional uses, for alcohol, 5m of 10mm tube is appropriate for a boiler power of 300 watts, so it is not built for speed. If you want lots of knowledge you really need to go over to Riku's ARC forum, as they have the experience.

There are better air cooled still designs as this one is a real granddaddy, but it does work.

I have one but I am looking at it from a slightly different perspective. For a start I think of it as a pot still. I am intending to run it real slow to start, in reflux mode, but this is to experiment with heads compression. After that it will be powered up and run as a pot still.

For me it is a curiosity - something I can play with - I have visions of a Sterling engine powered fan (driven by the heat in the boiler) to provide additional cooling to the coil. At the moment I have a spiral liebig on it, but ultimately I would like it to be fully air cooled. In reality I think there will still be some water involved, to boost the cooling capacity - most likely this will be evapourative cooling added to the coils (swamp cooling).

[johnny108]

Imagine a form of this still- spiral pot riser, and an air cooled coiled condensor. Both coils were formed around plastic 1.25L soda bottles- allowing for a bottle to be placed inside the coil to improve condensor efficiency, or to act as a kind of CM still.
Why the not-so-perfect design? Trying to get repeatable results will be more fun, plus, I work 6 days a week, and on Sunday- my wife likes to try and drag me to the in-laws...
Running a batch that takes "all day" will give me back my day off.

[Texas Jim]

Someone here had a stove top still that had an air cooled coil - it had cooling fins attached like in a car radiator.

[oceansgreen]

so, obviously one whould never copy that link directly, the thought of using plastic +heat, even low heat is scary to me, thats not even mentioning the alcohol involved

so i thought about doing something like this on my own, and im lucky i stumbled on this thread, so i can get some questions answered and learn a bit before venturing into making one myself

one would be, why is the second coil on the right needed? the pdf mentioned it helps it to condense from what i gathered... is it possible that if one did simply one coil on the way upwards and then just did a simple elbow after the coil that the alcohol would condense on its own, or is there not enough surface area for proper condensation?
what if the first coil had a chunk of ice or a frozen stainless water bottle placed between and touching the coils on the first set of coils? would the second set be nessacary then?
i like this design for replacing a column and such because it seems more compact and simple, both things that appeal to me, but i want to make sure its safe before using it obviously

[myles]

so, obviously one whould never copy that link directly, the thought of using plastic +heat, even low heat is scary to me, thats not even mentioning the alcohol involved

so i thought about doing something like this on my own, and im lucky i stumbled on this thread, so i can get some questions answered and learn a bit before venturing into making one myself

one would be, why is the second coil on the right needed? the pdf mentioned it helps it to condense from what i gathered... is it possible that if one did simply one coil on the way upwards and then just did a simple elbow after the coil that the alcohol would condense on its own, or is there not enough surface area for proper condensation?
what if the first coil had a chunk of ice or a frozen stainless water bottle placed between and touching the coils on the first set of coils? would the second set be nessacary then?
i like this design for replacing a column and such because it seems more compact and simple, both things that appeal to me, but i want to make sure its safe before using it obviously

In the original form this is a reflux still. The upwards coil is the reflux condenser / reflux column. No packing involved as it uses vapour and reflux condensate in contraflow over the internal surfaces of the coil. The second downwards coil is an air cooled product condenser. In this format it is good for slowly removing water - probably best considered for something like a very low power or solar stripping still.

Add in a packed column before the upwards coil and you get somewhat better results in the fractionating department. HOWEVER, it must be stressed that this is a low power device. A 5m x 10mm coil will cope with about 300w

[oceansgreen]

thank you for clearing that up myles
i have gotten a couple responses to my thread here: http://homedistiller.org/forum/viewtopi ... 8#p7053168
and from what ive been told, the spiral will sometimes get bubbling or surging/puking as they put it, which would be pressure forcing less refined liquid through the still and into the product, has anyone had this happen when running a spiral still, if anyone has used one anyway

[myles]

What you describe is a valid problem and it depends on the tube diameter and the power input. With passive air cooling these are always going to be low power devices, that is the restriction of passive air cooling. You can do things to make the cooling more efficient but you will always run into the same problem eventually.

If your vapour speed gets too high there is a point when the vapour supports the liquid that is trying to flow downwards under gravity, and pushes it up the tube.

You just have to run within the power constraints of your design. Do you really NEED to run air cooled. You can get better results with a drip fed swamp cooled coil that will use minimal water. Am I right in thinking that this is for a packaway small still? If so it is possible, but not the easiest thing in the world to run. Making cuts on a small boiler is notoriously difficult.