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3” bubble plate with 5 plates vs 3” packed section 1m+ long

PostPosted: Thu Jan 23, 2020 7:16 pm
by GINKING
Hi,

I have few questions to work out which still type would be better to produce a nice neutral spirit for gin.

Question 1:
Which of the following still designs would produce the better neutral:
1. 3” bubble plate column with 5 plates + 500mm packed section
2. 3” Column with long packed section (~1.5m)

Is there a point where a really long packed section is better than the plated/packed section combo?

Both would be made of full copper, the only bits of stainless steel would be the ferrules.

Question 2:
For a 3”column build how tall/long should each plated tee section be? I’m guessing around the 6” mark??

Question 3:
How long should the 3” dephlegmator reflux condenser be? Is 6” too short/long?

Thanks for your assistance in advance.

ginking

Re: 3” bubble plate with 5 plates vs 3” packed section 1m+ l

PostPosted: Thu Jan 23, 2020 8:22 pm
by RC Al
1. A 1.5m packed column will produce neutral faster than the plates plus packed as described, the plates without the packed produce rum/bourbon/scotch in a single pass without stripping
1m packed and 5 plates - roughly the same as 1.5 packed

2. 6" is fine, more can be better, it depends on the rest of the unit

3. For a shotgun, 6" is generally considered too long and slow to reflect adjustments, many who have done 4" said they would try even smaller. The trick is to put as many tubes in there as you can fit, no closer than 1.25x tube diameter and no further than 1.5x tube diameter apart, Centre to Centre. Baffles every 2", This is the recommended spacing for industrial coolers and helps the condenser be efficient and easily adjustable as there is less mass of water - the heat is transferred away more quickly

Re: 3” bubble plate with 5 plates vs 3” packed section 1m+ l

PostPosted: Thu Jan 23, 2020 8:22 pm
by bluc
Combine the two if you have roof height :handgestures-thumbupleft:

Re: 3” bubble plate with 5 plates vs 3” packed section 1m+ l

PostPosted: Thu Jan 23, 2020 8:36 pm
by db1979
In the early days of people making bubblers there was talk of a rule that the plate spacing should not be smaller than the column diameter. There's an issue with entrainment, where vapour components can become trapped in upcoming vapour or bubbles and the plates become less effective at separating different components. As the diameter increases, vapour speed can also increase and more separation is needed. So you'll want to go a minimum distance of 3" for a 3" bubbler, but I think 6" is way too much. The more metal the longer it takes to heat up and the more height starts to limit where you can run your still (you might not be able to run it in future where you are currently planning on running it). Also if you're willing to go 6" spacing, why not go smaller so you could fit in more plates later on (or a Carter head) if that's what you decide to do later.

6" for an RC is also way too much, my RC on my 4" is 85 mm. My 2" RC is about 50 mm. I think you could very easily get away with a 75 mm RC but it will depend on the internal tubes, try to pack in as many as you can.

Re: 3” bubble plate with 5 plates vs 3” packed section 1m+ l

PostPosted: Thu Jan 23, 2020 9:18 pm
by GINKING
Thanks for the information guys.

Will the the 1.5m packed section produce a better quality neutral?

Re: 3” bubble plate with 5 plates vs 3” packed section 1m+ l

PostPosted: Thu Jan 23, 2020 9:22 pm
by RC Al
Either will produce a good neutral, the packed column will do it faster

Re: 3” bubble plate with 5 plates vs 3” packed section 1m+ l

PostPosted: Thu Jan 23, 2020 9:34 pm
by bluc
RC Al wrote:Either will produce a good neutral, the packed column will do it faster

:text-+1:

Re: 3” bubble plate with 5 plates vs 3” packed section 1m+ l

PostPosted: Fri Jan 24, 2020 8:19 am
by scythe
With plate spacing you need to consider downcomer length as well.
I reckon column diameter plus an inch is good, your plates are not going to be foaming up unless it pukes.
Most of the time it will be about 1/3 full of bubbles, maybe.

Re: 3” bubble plate with 5 plates vs 3” packed section 1m+ l

PostPosted: Fri Jan 24, 2020 9:52 am
by peter01010101
Please correct me if I'm wrong, (I'm new to bubblers) I thought one advantage of plates + packed section was the convenience of not having to strip the wash. If this is the case, would that apply to a 1.5m packed section also? Or would both need to be running low wines @ 40% to achieve a clean neutral?
Cheers.

Re: 3” bubble plate with 5 plates vs 3” packed section 1m+ l

PostPosted: Fri Jan 24, 2020 10:18 am
by bluc
I say both :handgestures-thumbupleft:

Re: 3” bubble plate with 5 plates vs 3” packed section 1m+ l

PostPosted: Fri Jan 24, 2020 1:32 pm
by peter01010101
bluc wrote:I say both :handgestures-thumbupleft:



Sorry bluc, just to clarify. Both running low wines? or both running from a wash? :wtf:

Re: 3” bubble plate with 5 plates vs 3” packed section 1m+ l

PostPosted: Fri Jan 24, 2020 1:35 pm
by bluc
For neutral I would say use low wines..

Re: 3” bubble plate with 5 plates vs 3” packed section 1m+ l

PostPosted: Fri Jan 24, 2020 3:00 pm
by peter01010101
:text-thankyoublue: :handgestures-thumbupleft:

Re: 3” bubble plate with 5 plates vs 3” packed section 1m+ l

PostPosted: Sat Jan 25, 2020 10:04 am
by woodduck
I don't strip with my bubbler and didn't with my boka you just need to run slower. I say try it and see what works for you.

I think if I was making a neutral still I would go all packed section.

Re: 3” bubble plate with 5 plates vs 3” packed section 1m+ l

PostPosted: Sat Jan 25, 2020 1:55 pm
by GINKING
How long should the packed section be to get the best (very good) neutral for:
1. a 3" column
2. a 4" column

Re: 3” bubble plate with 5 plates vs 3” packed section 1m+ l

PostPosted: Sat Jan 25, 2020 2:11 pm
by RC Al
To get to 95% you need at least 15 "Plates" if you have more, you can run the still faster, Recommended length is usually 20-30x diameter, once you go past 30x, the returns diminish rapidly. You can run with less plates, but you have to reflux more (takes longer)
Packed with scrubbers a 3" has an equivalent to a plate distance of around 100mm, a 4" is around 80mm

Re: 3” bubble plate with 5 plates vs 3” packed section 1m+ l

PostPosted: Sat Jan 25, 2020 7:37 pm
by GINKING
Nice,

Thanks RC AL.

How did you work that out?

What if its packed with other material? How do you work out the equivalent plate distances?

Re: 3” bubble plate with 5 plates vs 3” packed section 1m+ l

PostPosted: Sat Jan 25, 2020 8:05 pm
by GINKING
So based on the 20x diameter as a starting point;

The 3" packed column would need to be at least 1524mm
divided by 100mm gives No. of plates = 15 plates

The 4" packed column would need to be at least 2032mm
divided by 80mm gives No. of plates = 25 plates
Does that seem overkill for the 4" (would 1600mm do i.e. approx. 20 plates equivalent)

Re: 3” bubble plate with 5 plates vs 3” packed section 1m+ l

PostPosted: Sat Jan 25, 2020 9:38 pm
by RC Al
There are some rough and ready calcs on home distiller.org based on the math in the book "the complete distiller" that can be found in the library here

There are a few setups around that require a ladder

Ceiling height is of great concern, as is boiler capacity, the 1.6m column would easier in both regards, I can't find the answer to liquid capacity of a column vs packing density currently but a large column can run the risk of holding more product than the boiler can provide ie 40l@10% is only 4l of alc, I personally don't see an issue with using water to push it through, but for some reason people seem adverse to that concept. Stripping wash and then running the boiler at 40% abv gets arrond this issue (whatever the issue is)

Also of concern with larger diameters is weight, of the column itself and of the packing, scrubbers will crush under the weight of the product above over long legnths, unless it's sectioned off and supports are added. Using scoria rock instead will combat that somewhat, but this makes the column much heavier overall too

How much power are you planning on? A 4" would want at least 4kw, potentially much more

Not trying to put you off, just making you aware that as you scale up, things get interesting

Re: 3” bubble plate with 5 plates vs 3” packed section 1m+ l

PostPosted: Thu Jan 30, 2020 8:00 pm
by GINKING
In terms of neutral quality would there be any difference (apart from speed) between a 3" and 4" version of the following:
- bubble plate column with 5 plates + 500mm packed section + Reflux Condenser

I'm trying to work out if I should make a 3" or 4" version of the Neutraliser Still (something similar anyway)

Thanks for your help.