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Which is better? Which is easier? Why

It is generally believed that packing works better in smaller columns and plates work better in larger columns. Perforated or bubble cap. And for the most part that holds true.

Before Old Dog explored making a four inch Perforated plate column, hobby and commercial distillers were split apart right here. Even small batch distilleries used plated column stills. (and still do)
On the hobby side guys working with two inch were exploring packing solutions. Since OD built the first Magic Flute, members have made several modifications and down scaled it even further. Some with success down to 3 inch but not much luck on two inch.

During distillation in a forced reflux column or a column run so slow as to be in a total reflux state, different alcohol fractions find their comfort zone in the column and settle in.
This is Equilibrium.
Starting at the bottom and consisting of water and alcohol the lower Boiling point fractions find there way farther up the column as higher volatiles, occupy the higher spaces. On a very tall column of 20 plates or more they will separate quite well with little help. On shorter columns forced reflux is used to create greater evaporation cycles to enrich the mixture.
(typically using a dephlagometer or reflux condenser)
The evaporation cycle occurs at the surface of liquid at each plate or packing surface. The greater the evaporation cycles the greater the enrichment.
This is Reflux ratio. By using a high reflux ratio during batch distillation ABV can be raised and fractions can be taken off separately with some success. Key to successful column distillation is establishing this equilibrium and taking off slowly enough as to not disturb it, what ever that equilibrium mixture happens to be. Tall columns will provide greater separation of fractions than short.

Packing efficiency is rated in comparison to plates. HETP's, Height Equivalent to Theoretical Plates.

What is good and bad about plates.
Plates are great for commercial use or having fun starring through little windows. Plates can be used to almost any diameter with predictable repeatable results. They provide a consistent product determined by the number of plates. They are also limited by the number of plates. They are low maintenance once built and installed. Most micro distillers are using plated batch columns to make flavored liquor. Few have tall enough columns to make vodka as designated by the TTB at 190p.
A four plate column can be run with a high enough reflux ratio to create over 180p but provide very little separation between fractions resulting in heavier flavored spirits. Another down side to plates is the inability to run at higher vapor speeds. With boiling action at each plate, entrainment can easily occur if distillate splashes on the plate above contaminating the fraction. Vapor speeds must be low enough to avoid entrainment.
Plated columns can predictably produce the same flavor profile from a given ferment when run with the same protocol.
Plated systems do not appear to work well below three inch. Likely because of the low vapor speeds required to avoid entrainment as compared to packing. Four to Ten Plates will not make neutral .

What is good and bad about packing?
Generally packing has been limited to three or four inch diameter and considered not practical for anything larger. There is a miss belief that packing must be removed and cleaned regularly that discourages many from its use on a larger scale. Above four inch typical packing can collapse under its own weight destroying consistent vapor space. There are options and remedies there.

Even a basic packing can provide greater HETPs than a plated column.
Packing provides better fraction separation and higher overall ABV. Why? Several reasons. First, greater surface area. If you visualize that every surface is like a tiny plate with evaporation cycles occurring at the surface of the liquid you can easily see that many more evaporation cycles can occur in a given distance than typical plates. Second, and exactly opposite of plate function these tiny surfaces are not boiling and splashing very darn far. Entrainment is greatly reduced.
Some members have had great success adding packing above their plated columns. I am not sure if this is because they have added more surface area or reduced entrainment by controlling splashing or both.
Different risks do appear with packing. Channeling or wall affect channeling can drastically reduce packing performance. Where there is enough space for falling distillate to build and run like a small river, gravity takes over and defeats equilibrium by disrupting evaporation cycles. Distillate should flow down wick like. Wall affect channeling is easily solved or reduced by insulating the column. Internal channeling is solved by correct density.
Shinny or hard surfaces that do not encourage liquid to cling add to the problem of channelling and reduce evaporation cycles. Substrate should have a very low energy surface to encourage low surface tension. Think old paint job V/S new paint job with good wax. Dull good. Shinny bad.

So which one?
I can only ask, What do you want to make? If you are a micro distiller and want to make a consistent flavored product I say plated for sure. Number of plates will determine flavor profile. If you want to make Rum. Bubble cap plates, or minimal perforated plates will produce great flavor.
When running a still with fewer plates, lack of fraction separation or “smearing” is a given and equals flavor.

Packing can certainly be made to work on larger diameters by simply providing structure to maintain proper placement that considers previous notations. There is no limit. I could build a 24” Azeotrope column that would fit into your garage and would produce like crazy.
If you are a hobby distiller and want to make a variety of different products, I say packing. Even on four or six inch columns. They can be run faster or with reduced reflux ratio to make flavored products.

When batch distilling with a packed column fractions do not magically disappear.
They are taken off accurately as they distill. You can easily make whiskey by blending the tails and desirable fractions together during blending or keep only the perfectly tasteless hearts for vodka. Your choice. For more information on packings check out my thread “Lets talk Column packing”

Chime in with your thoughts or questions. PM me if you want. I will respond to all.

Mash Rookie

MR, this thread is on PG 2. I don't want it to slip by, especially since you took so much time to post and add the question. So here goes...
Since diameter =speed. And I have access now to 6" stainless. On a keg, (or 27gal Cerberus), would 6" be inappropriate for hobby scale? Packed or platted?
I realise I may be jumping ahead a little bit, but think about it. Diameter=speed.

Maybe just a bump of the thread, but this one is important I think, thanks MR...

I think this is why LWTS is on the right track. Bubble caps/plates with packing above...


What is good and bad about packing? Generally packing has been limited to three or four inch diameter and considered not practical for anything larger. There is a miss belief that packing must be removed and cleaned regularly that discourages many from its use on a larger scale. Above four inch typical packing can collapse under its own weight destroying consistent vapor space. There are options and remedies there.

Even a basic packing can provide greater HETPs than a plated column. Packing provides better fraction separation and higher overall ABV. Why? Several reasons. First, greater surface area. If you visualize that every surface is like a tiny plate with evaporation cycles occurring at the surface of the liquid you can easily see that many more evaporation cycles can occur in a given distance than typical plates. Second, and exactly opposite of plate function these tiny surfaces are not boiling and splashing very darn far. Entrainment is greatly reduced. Some members have had great success adding packing above their plated columns. I am not sure if this is because they have added more surface area or reduced entrainment by controlling splashing or both. Different risks do appear with packing. Channeling or wall affect channeling can drastically reduce packing performance. Where there is enough space for falling distillate to build and run like a small river, gravity takes over and defeats equilibrium by disrupting evaporation cycles. Distillate should flow down wick like. Wall affect channeling is easily solved or reduced by insulating the column. Internal channeling is solved by correct density.

wacabi1 wrote:MR, this thread is on PG 2. I don't want it to slip by, especially since you took so much time to post and add the question. So here goes...
Since diameter =speed. And I have access now to 6" stainless. On a keg, (or 27gal Cerberus), would 6" be inappropriate for hobby scale? Packed or platted?
I realise I may be jumping ahead a little bit, but think about it. Diameter=speed.

Maybe just a bump of the thread, but this one is important I think, thanks MR...

I have concerns about the 6" size. Mostly these are to do with the volume of the column relative to the volume of the boiler. The boiler has to be big enough that the transitions between the cuts occupy enough space within the column to make the cuts practical. If the transitions are too small it just makes it hard work, in the same way as it is hard to make cuts on a 1 gallon pot still.

I am sure there must be a guide somewhere to the column / boiler charge question.

Taken to extremes you could end up after stabilisation with the entire volatile content stacked within the column. Not sure that would be good, from a purely practical perspective. Your temperature gradient within the column might be a bit too compressed for ease of use.

I edited this post as I didn't want the wording to give the wrong impression.

I feel we as hobbyists have a long way to go in the research of what is best. And feel we have only really scratched the surface. We are also hindered by tradition and perceived opinions. To many different goals and opinions of what shoulds. Can make research blinded.

Thanks for the post MR.

Nice write up, MR. Thanks!

Odin.

MR glad you started this as it has me back re-studying design ideas. I agree with Myles on the six inch diameter column verses boiler size and this is one reason going larger favors plates as plate columns work better in larger diameter as packed columns are prone to severe maldistribution problems. I also agree with your comment about comparison between plates and packed columns by HETP. Recently I have been reading up on HETP (height equivalent of a theoretical plate) and HTU (height of transfer unit). The math can be carried out by each method with similar results which at times has me lost even with a minor in math. We tend to use the HETP method as the calculations are easier.

You have given a basic understanding of these comparisons that I think explains in theory that probably has many members shaking their head. The reason I say this is there are many factors to numerous to discuss in this thread and you have touched on the research at a small scale that we all applaud. I think many members think of packing in just terms of mesh and not the other packing material available on the market.

Some other factors that should be weighed and maybe not on this thread that should influence ones decision besides cost, and difficulty in building are:
Foaming tendency is greater on trays than with packing due to higher vapor and liquid velocities.

Packing generally have lower liquid holdup than trays.

You get a higher liquid rate with trays because multi-pass trays lower the liquid load.

Edit Some of these you touched on re-reading your post just stated differently.

I was wondering if on the bottom of our deflag putting a small nail shape in the bottom would help it to follow down the center of the packing? Instead of building a centering ring. I am building a bubble plate set up with a 20 inch packed column on top below my deflag.

wacabi1 wrote:MR, this thread is on PG 2. I don't want it to slip by, especially since you took so much time to post and add the question. So here goes...
Since diameter =speed. And I have access now to 6" stainless. On a keg, (or 27gal Cerberus), would 6" be inappropriate for hobby scale? Packed or platted?
I realise I may be jumping ahead a little bit, but think about it. Diameter=speed.

Maybe just a bump of the thread, but this one is important I think, thanks MR...

Six inch is absolutely too large for the hobby. Myles has it nailed. The sizes demands a boiler large enough to be commercial to even function. A four inch will run a full keg charge in an hour and a half once hot. How fast do you need to go? A four inch almost requires 26 gallons.

I have a six inch column that I have run twice. On the first run my 5500 watts was not enough power maintain correct vapor speed for decent reflux ratio and it produced below what a four inch would do. On my second run with a gas burner and a full keg charge the run was over in thirty minutes. Cuts were impossible to make at that speed. I can not even test with 13 gallons. I use math to translate up.

Needing a 50- 100 gallon boiler to function, It really crosses the line of any hobby description I can think of.

DuckofDeath wrote:I was wondering if on the bottom of our deflag putting a small nail shape in the bottom would help it to follow down the center of the packing? Instead of building a centering ring. I am building a bubble plate set up with a 20 inch packed column on top below my deflag.

My observations in my glass column showed that distillate drips off my dephlemometer pretty evenly. I dont think it requires any help or a centering ring. On a taller packed columns centering rings have been used to offset wall affect channeling. A better solution is to insulate the column to avoid additional condensing there. My dephlag uses 1/2" pipe.

[quote="Bushman"]
You have given a basic understanding of these comparisons that I think explains in theory that probably has many members shaking their head. The reason I say this is there are many factors to numerous to discuss in this thread and you have touched on the research at a small scale that we all applaud. I think many members think of packing in just terms of mesh and not the other packing material available on the market.
Thanks BM. I am trying to explain it clear enough that a basic understanding can be had by most.

Some other factors that should be weighed and maybe not on this thread that should influence ones decision besides cost, and difficulty in building are:
Foaming tendency is greater on trays than with packing due to higher vapor and liquid velocities.
Foaming is where entrainment reduces efficiency. I witnessed this on my glass plated flute. Below twenty amps it stacked beautifully with each plate boiling away at about half full. Above twenty amps they foamed up against the plates above. You could see entrainment happening that disables the next plate.
Packing generally have lower liquid holdup than trays.
This a down side of packing if it is loose enough to allow channeling. The hybrid design that some guys are building with plates and packing might be a good solution. In a sense they help each other. Plates controlling channeling, packing controlling entrainment and providing additional surface area.
You get a higher liquid rate with trays because multi-pass trays lower the liquid load. Down comers?
quote]

MR
I been following these treads and learning as i go and also building as i read and learn. Im building a 3'' slant plate (Bok) off of a 13 gal boiler with dual 3500 watt (controlled) elements. Im aiming to make brandy ,whiskey and a little flavored vodka. My still will be able to run either reflux or pot mode. I wanna put a preferated plate about 12'' above the boiler before it hits the copper packing. Would this help or hurt the process. Also i wanna build a bubble cap plate to install later using triclamps and ferrules to further my knowledge on this. How do u home build a bubble plate? maybe point me in the right direction if im at the wrong place>
THANKS

Shawn,
Samohon has a very nice tutorial on how to build a bubble cap plate. Look for it in the plans category or maybe his OD Mark 2 thread. What is your goal there?
It might be helpful to read the Flute talk thread. (yes its long) The FlyingDutchman does an incredible job of explaining distillation. He is an organic chemist and taught me much. Search his threads. There is some great stuff there.

On your rig, if you have a product condenser and take off you should be able to run fast without refluxing and take off like a pot still. When you desire neutral you would use the reflux condenser and take off at the slant plate. VM might work better. There are some new hybrids being built now.

Putting a plate below your packing will have the result of lowering efficiency. It will reduce packing surface area and evaporation cycles.

MR can you explain a little better. About what you mean in this statement about lowering efficiency? Or maybe your definition of efficiency? I'm a little cornfused by it.

Putting a plate below your packing will have the result of lowering efficiency. It will reduce packing surface area and evaporation cycles.

Yes, I don't understand either. I'm thinking of LWTS here. Are you saying for the same distance in column height? Because it takes up room within the height of the column that could be used for packing? Other than that, I don't get it...

wacabi1 wrote:Yes, I don't understand either. I'm thinking of LWTS here. Are you saying for the same distance in column height? Because it takes up room within the height of the column that could be used for packing? Other than that, I don't get it...

Be happy to explain guys.” I wanna put a preferated plate about 12'' above the boiler before it hits the copper packing.” All he is doing is increasing his boiler chamber space and decreasing column area and packing surface area. In a sense putting a shorter column on a larger boiler.

For those that are just starting to wrap your head around distillation I will explain a little further. (Thank you FlyingDutchman for your wisdom)

At each plate a distillation cycle occurs. The greater the number of plates the greater the number of distillations. (evaporation cycles.) This is usually limited by available height. Minimum spacing between plates is determined by vapor speed. Too much can defeat the plate above by splashing (Entrainment). That limits the number of plates that can be used in a given height.

Packing provides greater surface area for distillation cycles in a given space. Additional distillations can also be obtained by using a reflux condenser. They are affective for raising ABV but fraction separation is limited by the physical number of plates. That is why four plates will hit 92% but not make neutral.

Consider that at each plate when a distillation cycle occurs, it is not just separation of alcohol and water, but also the content of the alcohol. Different alcohols or mixtures of alcohols are called fractions. The fraction that wants to find its home or comfort spot in a column. In a perfect world, with enough plates and a tall enough column everybody has their own chair to sit in. This is equilibrium. Once equilibrium is established, take off at a slow enough rate will not disturb it. Heads can be taken and hearts can be taken very cleanly as fractions are allowed to remain in the column. After hearts have been taken tails will move up to occupy higher places in the column.

Ask away. I will try to find better discriptions.
MR

Be happy to explain guys.” I wanna put a preferated plate about 12'' above the boiler before it hits the copper packing.” All he is doing is increasing his boiler chamber space and decreasing column area and packing surface area. In a sense putting a shorter column on a larger boiler.

I would agree that 12" is wasted space. That could be utilized by either plates or packing.

But I'm still cornfuse as to your definition of efficiency?

Efficiency of the column as related to its ability to do the job of distilling alcohol. If he is using a 3' column and defeats the first one third by placing a plate at 12 inches, he has reduced its efficiency by one third. Whether it is packing or plates.

That is not to say that he may not like what he produces with only 24” of column. Just that there is no advantage in having the first plate 12” up from the boiler before any additional plates or packing.

But, You know this and are just having fun screwing with me. Hmm Very efficient grasshopper..

UJCornfused? or infused?

No I'm being serious MR. Was hopping you didn't think I wasn't.
I admit I missed the whole 12" thing in his post. I was just trying to understand your post. And it just wasn't working out in my head as to what you were trying to say.

Putting a plate below your packing will have the result of lowering efficiency. It will reduce packing surface area and evaporation cycles.

I read that as to say. Adding a plate under a packed column will make it less efficient. When my findings say it would increase its efficiency.

But like I said I agree that the 12" below the plate is wasted space. Move the plate to the bottom and add 12" of packing above it.

Move the plate to the bottom and add 12" of packing above it.

I agree PP.



I find it interesting that many are building hybrid stills using combinations of packings and plates. I am anxious to hear your results. In a sense we have come full circle from packings to flutes, thumpers than bubble caps and now to combining them all.

I understand that several of you are adding packing to your plated still columns. EG reported great results on the packing thread. What are you using? How has it changed your results? PP? LW? Guys?

Myles stated on his build thread that he is building a “Azeotrope still” and will use other stills for rum or whiskey.

Packings allow us to make azeotrope quality easier than perf or bubble cap plates. Recently we have shown that they are not limited to small diameter that limited speeds.

Now that I have done that with my packing designs my goal is to develop a operating protocol or mechanical solution so the same still can be used for all types of washes. In a sense I am working backwards. Mechanically de-tuning a packed still with a turn of a valve or changing power and cooling settings to operate differently. I am enjoying decent success with the later.

When I complete my packing studies and have tested everything I can get my hands on I want to explore packings used in a much larger diameter that incorporates a support structure in a plate fashion.

Picture something like 12”, 18”, 24” column with ”packing plates” 3”-4” thick. Packing trays? The reason for separation is to allow for a true vapor bypass system.Rarely used on a low plate count still. Something that could be quite affective on this type of design.
I think I can create a very low HETP at speeds commercial distilleries want. At a height that will fit in any building at a price that start ups can afford.

MR

whewwwww what a read.

Enlightening ain't it lol.

Honestly it made my head hurt. To much thinkin. Any one heard how MR is doing?

Yea, haven't seen any posts from him in a while. He had some serious fascinating stuff. Real art went into his work!

halfbaked wrote:Honestly it made my head hurt. To much thinkin. Any one heard how MR is doing?

No, I swung by his house after Thanksgiving but didn't see much from the outside. He asked me month's ago not to contact him until he was ready to deal with his health issues so I didn't stop. The last I heard was in a response to an email I sent and he asked me to help him finish a still, I said let me know and I would come down but he never got back to me. He lives 1-1/2 hours from me but I will be heading down to visit family tonight and may try to swing by tomorrow.

If you get to see him wish him the best we miss him!

Hi Bushman,
Please wish him my best if you get to see him.

Tell him we miss him if you come in contact with him and hope he is doing well.