Pulling product off a bubble cap plate?

[Steve Broady]

I’ve been trying to find any threads where people have tried this, but it doesn’t seem common. There’s probably a very good reason for that, I admit.

Imagine a still with three bubble plates and a reflux condenser at the top. As I understand it, assuming that the RC can knock down all the power you’re putting in, it could just sit there and circulate all day long without anything coming out. Basically, it’s just a crappy heat pump, transferring the heat from the boiler into the cooling water and down the drain. Useless, perhaps, but at least stable.

I’ve read some comments that suggest that, VERY broadly speaking, tails will collect on the bottom plate, hearts in the middle, and heads at the top. I’m certain that it’s not that simple, especially because even with a fairy deep liquid level on a plate, there’s likely far more alcohol in the boiler than can be held on the plates. But just for the sake of discussion, let’s say that it’s at least somewhat related to what’s actually happening inside the still.

Could you put a drain on the middle plate and pull good product off, LM style? And more importantly, would there be any benefit to doing so, compared to either a pot still or any of a number of other more common still designs? As I understand it, this would be a liquid management still, but one aimed at flavored spirits instead of high purity neutral. And done right, it would not need as much vertical space, though possibly more than a simple pot still.

My interest is primarily in flavored spirits, especially whiskey and rum. I have no illusion that such a design would make a particularly good neutral. But would it make a good whiskey? Would it do a better job of separating the heads, hearts, and tails?

I’m absolutely game to try the idea for myself, but some of you have been doing this for a long time and have seen more things than I can even imagine. If it’s been tried and deemed a failure, I haven’t found it yet, but I wouldn’t be at all surprised and would be glad to learn.

[Sporacle]

Steve, there are plenty of stills that have drains on each plate.

I look at it this way, I have a valve on my plated still that valve is the cut points on my jars.
So for me the heads accumulate on the top plate and these are bled off through the deflagameter and collected, they are slowly replaced by the hearts and then the tails.

Does that make sense
That's the way it works in my muddled brain

[Yummyrum]

Steve , what you are suggesting sounds very much like how a Continuous still works . They do in-fact draw product of the “middle plates “ .

Problem is what you are suggesting is a batch version and as such the contents of the vapour will change throughout the run and therefore the product on each plate will also be changing .

A continuous still on the other hand has a continuous supply of the same vapour .The heads and tails are also drawn off creating a stable condition and ensuring the “hearts “ product will always be on certain plates .

I also think you would need a lot more than 3 plates to do it .

Still , you are an experimenter so my all means see how it works

[shadylane]

Everything that Yummy said.
Plus give it a try and keep us posted.

[Bolverk]

I imagine youre looking for something like the rectification/fractionating side of a continuous still or more aptly the rectification side of a coffey still. And yeah its really hard to get the temperature gradient right in the small sizes that we as hobbyist deal in. The smallest ones I've seen are the stilldragon continuous and the downunder still continuous... and even then they look to be 4" columns that are 10ft+ tall.

I'd venture you're going to need a dephlag above and below your take off plates to create the temperature zone where you'd want to collect.

[Steve Broady]

Everything that Yummy said.
Plus give it a try and keep us posted.

Nothing ventured, nothing gained, right? I just ordered some materials, so when those show up I’ll see what I can create. If nothing else, hopefully it’ll look pretty!

[shadylane]

If nothing else, hopefully it’ll look pretty!

Making it pretty increases the odds of having to cut it apart and try something different.

[LWTCS]

Captain's Hooch did a similar thing. Though his goal was mostly for pulling samples for data / better understanding.

As mentioned, without the continuous feed the still will run very similar to any other batch system in that the distillate stream will progressively change.

[Saltbush Bill]

Without having about thirty plates and a hugely tall column , I think your wasting your time.
You might learn from it but my gut feeling is that it won't be an improvement to a hobby size 4 or 5 plate column.

[Bolverk]

Are you planning on doing continuous or batch with this?

[Steve Broady]

Are you planning on doing continuous or batch with this?

Batch. I know it won’t make a single consistent product from start to finish. I’m sort of thinking about it as a modified pot still. And I’m also thinking that I might be able to pull heads off at the top plate, Boka style. I’m curious to see if I can tell a difference between the product I make with this and a pot still.

Worst case, I’ve made some plates bubble balls that can be used for another design. Or it’s a pretty still that’s pretty useless. Who knows?

[Bolverk]

Cool. Where are you getting the take off plates?

I've been fantasizing about building small hobby coffee still for months (just to satisfy my curiosity as well), so anything related has my interest.

[GrumbleStill]

Hi Steve, reading the thread, it seems like you’re building a relatively standard 3 plate bubble cap column, and then using it to experiment in a non standard way.

Just a thought, but why not give your new plated column a few runs as a regular cm or vm before starting the experiment? That way you’d have a good baseline for comparison, and have the benefit of all the experience here to help you iron out any teething problems. Fwiw I reckon the regular column config will probably give the better result, but science is built on experiments, not I reckons.

One other thing, just remember that unlike a normal LM, the liquid on those plates will be at boiling temperature, so will need to cooled down to room temp to be safe.

Cheers, have fun and be safe.

[Setsumi]

Hi Steve, reading the thread, it seems like you’re building a relatively standard 3 plate bubble cap column, and then using it to experiment in a non standard way.

Just a thought, but why not give your new plated column a few runs as a regular cm or vm before starting the experiment? That way you’d have a good baseline for comparison, and have the benefit of all the experience here to help you iron out any teething problems. Fwiw I reckon the regular column config will probably give the better result, but science is built on experiments, not I reckons.

One other thing, just remember that unlike a normal LM, the liquid on those plates will be at boiling temperature, so will need to cooled down to room temp to be safe.

Cheers, have fun and be safe.

If you mean 'at boiling temp' to be 98 to 100⁰C it will not. It will be boiling because of the vapour passing through and yes also because of the physics but it will be at a point between your reflux condenser coil temp and the vapour temp.

I agree with giving a normal plate run a chance with take off at the top plate regardless LM, VM or CM. If you do want draws at different plates with only 3 plates do a lintle at the bottom to keep the tails down. But myself would rather draw at the top of 5 plates for a batch run.

[GrumbleStill]

Hi Steve, reading the thread, it seems like you’re building a relatively standard 3 plate bubble cap column, and then using it to experiment in a non standard way.

Just a thought, but why not give your new plated column a few runs as a regular cm or vm before starting the experiment? That way you’d have a good baseline for comparison, and have the benefit of all the experience here to help you iron out any teething problems. Fwiw I reckon the regular column config will probably give the better result, but science is built on experiments, not I reckons.

One other thing, just remember that unlike a normal LM, the liquid on those plates will be at boiling temperature, so will need to cooled down to room temp to be safe.

Cheers, have fun and be safe.

If you mean 'at boiling temp' to be 98 to 100⁰C it will not. It will be boiling because of the vapour passing through and yes also because of the physics but it will be at a point between your reflux condenser coil temp and the vapour temp.

I agree with giving a normal plate run a chance with take off at the top plate regardless LM, VM or CM. If you do want draws at different plates with only 3 plates do a lintle at the bottom to keep the tails down. But myself would rather draw at the top of 5 plates for a batch run.

Hi Setsumi, Good point about the temps. I was referring to the boiling point of the alcohol/water mixture on the plate, not just water, but can see that probably wasn’t clear. With the OP planning to draw liquid off the centre of three plates, I agree it wouldn’t be up around 100°C, but by the same token, surely would have to be north of alcohol’s boiling point of 78°C? If so I’d argue it would still be too hot to handle safely without some extra cooling.

[Steve Broady]

Thanks, guys. Yes, I’ll definitely be cooling down the liquid, as with any LM still. I’m wondering if a simple coil of 1/4” copper tubing hanging free in the air would do the job, or if it needs a water jacket. Easy enough to test, of course.

One thing that appeals to me about this is that I can do exactly what has been suggested, and just use it as a normal 3 plate (or 4, if I build another one) sill. So even if the idea of taking product off the plates is completely worthless, I won’t have wasted all my time and money. But I’m me, I’m curious, and I want to find out what happens. Maybe I’ll make something just a tad bit simpler that makes a product that I like. I have my doubts, but I’m still going to try.

[drmiller100]

Hi Steve, reading the thread, it seems like you’re building a relatively standard 3 plate bubble cap column, and then using it to experiment in a non standard way.

Just a thought, but why not give your new plated column a few runs as a regular cm or vm before starting the experiment? That way you’d have a good baseline for comparison, and have the benefit of all the experience here to help you iron out any teething problems. Fwiw I reckon the regular column config will probably give the better result, but science is built on experiments, not I reckons.

One other thing, just remember that unlike a normal LM, the liquid on those plates will be at boiling temperature, so will need to cooled down to room temp to be safe.

Cheers, have fun and be safe.

If you mean 'at boiling temp' to be 98 to 100⁰C it will not. It will be boiling because of the vapour passing through and yes also because of the physics but it will be at a point between your reflux condenser coil temp and the vapour temp.

I agree with giving a normal plate run a chance with take off at the top plate regardless LM, VM or CM. If you do want draws at different plates with only 3 plates do a lintle at the bottom to keep the tails down. But myself would rather draw at the top of 5 plates for a batch run.

It will indeed be at the boiling temp of the liquid/vapor at that point in the column.
This will be somewhere between the boiling temp of the liquid in the boiler and the product at the top.

[Steve Broady]

This is going to take me just a little longer to start than I’d hoped. I have everything on hand to get started, and then I decided that it really needs to be 2” TC, rather than 1.5”. So I ordered another pull through tool, ferrules, clamps, gaskets, etc.

I know it won’t make any difference right now, because I’m sure that I’m limited by power input, but hopefully this will be something I can use in the future, and going 2” seems like the logical thing to do.

[Renhoekk]

Without going into heaps of detail, you need a big tower to make this feasible. If you're a home distiller with 6 plates, you're not going to get enough separation to make it worthwhile pulling product from a specific plate. The kind of setup you're describing is more typically seen in continuous columns with a lot more plates. A traditional Coffey still, which is a type of continuous still used to produce whiskey, usually has 25 plates in the stripping column and 40 plates in the spirit column. The product is tapped off near the top of the spirit column.

[Bolverk]

Any updates? Curious about this project...

[googe]

I've wanted to do this many times but always got put off due to laziness and what others say about it. In reality, I'd spend my time and.money on a new idea of distilling. Most small additive ideas on our level doesnt work well. But, I would never discourage you from.having.a.go, i.spent endless time and money on building stuff cause I wanted to. Like LWTCS said, have a look at captainhoochs build, I cant find the thread! He did take offs on all plates and very detailed. Good luck mate.

[Saltbush Bill]

This what your looking for Goo?......Hoochy , the man of many stills....and skills
viewtopic.php?p=7305844#p7305844

[Bolverk]

SBB, thanks for that, I hadn't seen that thread

[Steve Broady]

Any updates? Curious about this project...

Not yet, unfortunately. I’ve got the parts sitting here, but I haven’t had time to build anything with them yet. Just yesterday, I finally finished my dual 110/220v controller, so maybe some bubble plates can bubble their way up to the top of the priority list. As long as more things don’t brag around the house, or other needs arise first.

[Bolverk]

No sweat, I'm subscribed so I'll get the update when you get around to it.

Thanks!