Bubble Plate Still Flooding

[CopperFiend]

Dear Hivemind,

This is my first post and I apologise for it being a noob post. I have searched the forums using all the combinations of search terms I could think of to no avail. Feel free to tell me to read a book. However, I have experimented a lot with my gear and cant get stable results.

I have a self built 2" bubble plate column with three modular plates, 3 up and 1 downcomer per plate, 12mm bore with 15mm caps (standard plumbing supplies). I can get 85% with a tiny bit of reflux but no matter what I do with the power or having the RC even off, I ALWAYS get either top or second plate flooding. It doesnt flood if I use virtually no power and a little reflux but then I can't get any meaningful offtake. I really hope there's something simple I'm doing wrong. I also know that a 3" column would be better but I struggle to get the materials required... and I've put a lot of work into his one now!

I would be extremely grateful for any advice you fine distillers can give.

Cheers.

[googe]

Most flooding is due to thw drains not being big enough. I would have thought 12mm would be ok on 2 inch if 3/4 inch is ok on a 4 inch still. Any chance of a pic of your plates?.

[Saltbush Bill]

Agree with googe......all flooding I have encountered was caused by a bottle neck in the plates abilty to drain.
Usually bad or to small downcommer design.
The situation can be exasperated by too much power to the boiler.

[CopperFiend]

Thank you for the replies guys. This is the above and below views of one of the plates. I've just realised, looking at the image that there is actually very little room for liquid to get out on the underside of that downcomer. But I still want it to form a vapour lock so vapour cant get up? If I were to add more notches or even grind the cap down so there was a gap all the way around, but still able to keep a pocket of fluid in there, would that improve it?

Cheers! Please be kind to my shocking soldering!

[Saltbush Bill]

Id say thats your problem......grind/ cut more slots or bigger ones.
Please let us know if it improves the problem.
PS soldering looks fine to me.

[googe]

yep slots are way too small. could you fit a washer or two inside the downcomer cap to raise it off the plate?.

[Tummydoc]

More slots, and deeper. I'd start by doubling the number of slots and see if it still floods. If it does, increase the depth of the slots.

[CopperFiend]

Thank you everyone, I'll go and do a few edits. I have three plates at the moment so will change them all differently and then see which performs best.

Cheers

[Saltbush Bill]

More slots, and deeper. I'd start by doubling the number of slots and see if it still floods. If it does, increase the depth of the slots.

Yep way to approach the job

[CopperFiend]

Is there any way to test this without a run? I'm running out if sacrificial alcohol to run through it! I've been thinking of running a tap down and see if one edit to the downcomer makes more difference to the volume of water per second it can cope with before filling the plate but I assume some will be going down the up caps due to no vapour pressure from below?

[Yummyrum]

Use methylated spirits if you don’t have any more alcohol to play with . Water has different surface tension than alcohol and will act differently in static tests of hydraulics in your Downcomers
.

[LWTCS]

Running out?
Just collect everything and put it all back into the original kettle charge.

[LWTCS]

More slots, and deeper. I'd start by doubling the number of slots and see if it still floods. If it does, increase the depth of the slots.

Yep way to approach the job

You need to do a bit of math. Ideally the total open area in your bubble cap openings should be as close to the diameter of your column as possible.

[CopperFiend]

More slots, and deeper. I'd start by doubling the number of slots and see if it still floods. If it does, increase the depth of the slots.

Yep way to approach the job

You need to do a bit of math. Ideally the total open area in your bubble cap openings should be as close to the diameter of your column as possible.

That's an interesting point, I havent come across that before. I'd guess this is easier with larger columns and larger surface area plates?

[LWTCS]

Yes it is.
The more open area you can achieve, the wider the operating range.

The next variable is the draining capacity of each plate relative to vapor produced and reflux ratio.

Then liquid bed height in relation to plate spacing.
Deeper liquid beds and close spacing increases pressure in between the plates and adds to bad hydraulic behavior.

So there are a couple of variables.

[CopperFiend]

Thank you LWTCS, in theory then, I want my downcomer to be relatively short in it's extent above the level of the plate, to maintain a relatively thin layer of liquid? Obviously enough to cover the slots in the caps but not much more?

[LWTCS]

Well,,,you're kind of on the right track.
For example, rather than change your liquid bed height you could increase the plate spacing.

Btw, the liquid bed needs to remain deep enough so that the force of incoming vapor does not blow the liquid completely away from the bubble cap slot and allow the vapor to bypass the liquid bed.
Harry posted a video of this behavior a number of years ago. Not sure if that was here or over at AD?

EDIT: Not making any particular recommendation. Just trying to help you see how the variables can affect behavior.

[ideasinbeer]

hey Copperfiend. Not sure if you know but LWTCS is a hella good designer. Personally i would follow any input he gives if I was handy. Since I'm not I just soak it all in and support him when I can.

He'll get you on the right path.

Best of luck.

[CopperFiend]

That's exactly why I'm here! To soak up the pearls of wisdom offered and turn them into cool looking gear (that actually does the job intended hopefully if I read enough) and tasty drinks!

[fzbwfk9r]

any updates?

this

I am unable to source anything bigger than 2" at the moment, so am interested in how to get a 2" bubble cap column to work.

I'm looking at a single cap 1" or 1.25" diameter for now.

fluid bed height has me confused.
I see the bubble caps as just small thumpers..... but the dynamics are completely different. Thumpers have a lot of room whereas columns do not.

So far, my thought is to go 2" column
1" cap bubbler, a LOT of small slots cut into the caps.
Modular design using couplers, so I can alter the number of plates (up to 5 plates)
start off at 6" between plates. Can always cut them shorter... can't cut them longer!
CCVM for reflux control.
currently run with a leibig, but am looking at a shotgun 2" 4x1/2 tubes 12" minimum length cooling

I am concerned about quality over quantity.
I think the drive for very high ABV and high output levels are causing new distillers distress.
I think I need to start small, and once I get the process down for good product, then I can look at increasing volume.

[Setsumi]

Old threads susgests 2" bubblers not to work well. Myself have 4" flutes but helped build a few in 3" that works well. If i had to do one in 2" i would go perfs... mind even bigger rather go perfs...

Lower liquid depths works better for me. In a 2" column plate spacing would be more critical due to vapour speed, your 6" spacing would help.

Search for a thread by theflyingdutchmen on plate efficiency.

No worries to do CCVM, my flutes have CCVM heads and they work well.

Stilldragon has/had a 2.5" if i remember correct. Maybe look at dimensions there and scale back?

But a 2" packed colum may be less effort....

[Demy]

When I built the plates on 3 "I tried to keep the liquid bed lower as possible and only one big" Bubler ", allows me to run the column so calmly without excess power (I'm not a fan of" bring to the extreme "). The openings are certainly small, make sure you can control the power gradually.

[Saltbush Bill]

I cant begin to image how fiddly a 2 inch plated column would be to run, not to mention slow once it did produce.
All plated columns are a balancing act between reflux and power input, badly designed or too small downcomers just makes things worse/ harder.

[LWTCS]

I cant begin to image how fiddly a 2 inch plated column would be to run, not to mention slow once it did produce.
All plated columns are a balancing act between reflux and power input, badly designed or too small downcomers just makes things worse/ harder.

The 2.5" plate is not bad at all. It has a single bubble cap design with a fully integrated downcomer. There simply isn't enough real estate for a more traditional set of bubble caps and downcomer.

Bops along at 1.3-1.7 LPH.

[n_plains_drifter]

I may be two steps behind and a brick or two short of a full load, but here's what I'm going to be experimenting with at some point:

Just starting a 2" build of a CCVM that will augment my existing pot setup. Going modular, with a 2x2x2 tee going to my existing pot head connected to a long liebig. Minding my own business when I stumble into an interesting project. In accordance with the policies here, I won't mention or link to any off-site content.

The intent is to build 2" plates with custom made bubble caps and downcomers. The process involves fabricating the plate from sheet copper and the bubblers/downs from solid copper plasma cutting heads and 1/2" end caps. In this fashion, you can get 3 @1/2 bubblers , and 1@ 1/2 downcomers. I'm not sure it is possible given the surface area of the plate, but if I can force a 4th bubbler in there, I will.

That project is out on the timeline however. Most important is to get my column built and some practice just running reflux.

Best, Drifter

any updates?

this

I am unable to source anything bigger than 2" at the moment, so am interested in how to get a 2" bubble cap column to work.

I'm looking at a single cap 1" or 1.25" diameter for now.

fluid bed height has me confused.
I see the bubble caps as just small thumpers..... but the dynamics are completely different. Thumpers have a lot of room whereas columns do not.

So far, my thought is to go 2" column
1" cap bubbler, a LOT of small slots cut into the caps.
Modular design using couplers, so I can alter the number of plates (up to 5 plates)
start off at 6" between plates. Can always cut them shorter... can't cut them longer!
CCVM for reflux control.
currently run with a leibig, but am looking at a shotgun 2" 4x1/2 tubes 12" minimum length cooling

I am concerned about quality over quantity.
I think the drive for very high ABV and high output levels are causing new distillers distress.
I think I need to start small, and once I get the process down for good product, then I can look at increasing volume.

[fzbwfk9r]

Old threads susgests 2" bubblers not to work well. Myself have 4" flutes but helped build a few in 3" that works well. If i had to do one in 2" i would go perfs... mind even bigger rather go perfs...

Lower liquid depths works better for me. In a 2" column plate spacing would be more critical due to vapour speed, your 6" spacing would help.

Search for a thread by theflyingdutchmen on plate efficiency.

No worries to do CCVM, my flutes have CCVM heads and they work well.

Stilldragon has/had a 2.5" if i remember correct. Maybe look at dimensions there and scale back?

But a 2" packed column may be less effort....

I've read til my eyes bled.... and there were threads about successful 2" bubblers

BUT as SBB says, they are slower, but in my case, time is LESS money

4" copper tube up here is $90/ft, I am not sure I'll go that route

So, my initial thoughts/plan:
Modular 2" with each plate in it's own segment, connected by flanges
I already have my modular 2" TEE built for a pot still, so I can add a column of any type below. I can add Bubble Mods as I go.
I have just completed my 3 walled PC, and am working on my RC coil.

So, right now I can run as a pot still for stripping and spirit runs for whiskys
I do have 60" of 2" ready to pack for neutrals. Just need to solder in some flanges.

Bubbler will be for brown spirits as an option beyond simple pot stilling. I have read a lot of good things about bubble plates for flavour and high ABV allowing a "one and done" on bourbons etc.

one other thing I am doing.... whenever I see a copper pot/tea pot of some sort that appears to be big enough, I buy it.
I will cut these open and install a plate with caps, and 2" flanges so can pop them on the bottom of my column. As I make them, I can add them. It'll be ugly, but I don't care as long as the product tastes good.

one other thought is I do have a couple small pieces of 2" that I want to try as a short column with marbles to simulate 2-3 plates.
I have read up on a couple distillers who have good product coming from those.
if they don't work for me, I'll just add them to my packed column, or use them for more 2" plates or extensions for my UglyBubblers.
Options are good to have.

[Saltbush Bill]

Some random thoughts on the subject.

4" copper tube up here is $90/ft, I am not sure I'll go that route

Its not cheap even here, but in the end might be worth considering for these reasons.
Imo a two inch plated column is going to be woefully slow, in other words as boring as batshit to run.
Often small things are harder and fiddlier to make than a larger one.
The difference in time to make a 4 incher over a 2 inch is probably very little.
Having never run a two inch plated column Im only guessing , but my gut feeling is its going to be a fiddly little bastard to run. Tiny changes in water flow to the dephlegmator or energy input to the boiler will be needed for successful operation.
Hell a 4 inch can be fiddly enough if not properly set up.
Not trying to totally put you off the idea , but is the $ saving now worth the frustration and boredom that could be yours as time goes by as you sit and watch a tiny still dripping and spluttering.
If you ever want to get any booze truly aged , your going to be sitting next to that thing for many many many hours........hours that could be spent on other aspects of life.
on the flip side a 4 incher will happily put out 2+ Liters an hour of 92%.......or once cut and diluted roughly 4+L of white dog at 45%.
I be interested to see the output figures that a 2 incher can produce before its pushed to its limit and starts spewing tails into what could otherwise be drinkable product.
All just food for thought.
EDIT
Just noticed this post by Larry about a 2.5 incher, surprised at the maximum speed of 1.7.......but remember your talking going down another 1/2 inch in size.

The 2.5" plate is not bad at all. It has a single bubble cap design with a fully integrated downcomer. There simply isn't enough real estate for a more traditional set of bubble caps and downcomer.
Bops along at 1.3-1.7 LPH.

[Setsumi]

one other thing I am doing.... whenever I see a copper pot/tea pot of some sort that appears to be big enough, I buy it.
I will cut these open and install a plate with caps, and 2" flanges so can pop them on the bottom of my column. As I make them, I can add them. It'll be ugly, but I don't care as long as the product tastes good.

That will work pretty darn well and may get you in the better diameter range.

Search muggles on here!

[The Baker]

4" copper tube up here is $90/ft, I am not sure I'll go that route

Sheesh.
I bought old copper; four feet of four inch, ten feet of one inch and a partly damaged nearly three feet circle
of flat copper for ten dollars the lot.

Geoff

[fzbwfk9r]

Just noticed this post by Larry about a 2.5 incher, surprised at the maximum speed of 1.7.......but remember your talking going down another 1/2 inch in size.

The 2.5" plate is not bad at all. It has a single bubble cap design with a fully integrated downcomer. There simply isn't enough real estate for a more traditional set of bubble caps and downcomer.
Bops along at 1.3-1.7 LPH.

From what I've read, 1LPH is pushing it for a 2", and 0.8LPH is a better target