Lets Talk Column Packing

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mash rookie
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Lets Talk Column Packing

Post by mash rookie »

I want to explore the pros and cons of different packings. It is interesting that several people are working in this direction ATM. It has come full circle back to packing and HETP’s after a nice ride through the orchestra’s reed and percussion sections. I will be back reading at the parent site looking for tiny clues.

I have posted some of my tests and conclusions on Myles reflux splitting thread. I am going to throw out some thoughts and theories about packing and possible packing alternatives. I can expand if your not sick of listening to me.

My thoughts and tests are going towards finer tighter packing. I want to find the balance between maximum density ( surface area) that can be used and correct vapor speed for the packing, column diameter and take off speeds.

I am visualizing every tiny surface like a tiny plate, each one enjoying multiple evaporation cycles. Two issues arise. One, Insufficient space for falling reflux to travel without choking the column. Two, Creation of back pressure that reduces the boiling point separation of fractions, reducing packing effectiveness in a short area.

All the talk is about the new SPP. Has anybody here used it yet? There are other varieties of commercially made pour in packings for distillation.

We have all read about or tried marbles, Raching rings, stainless scrubbers, copper scrubbers, broken pottery or broken glass. I have used broken glass, scrubbers and copper wire wool of varying densities. I use acid etching to improve surface areas.

I bought a huge $5 bag of Lava rock Thursday for a fire pit on my deck. Wow. It is very porous looking. It could be crushed and screen sized for varying density. Has anybody ever tried it? It would take about a $1 worth of it to fill a column.

My next test will be with stainless steel wool available from Grainger in my glass column.

What do you think would work??
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Re: Lets Talk Column Packing

Post by NcHooch »

You're not actually planning on drinkin hooch distilled through lava rock, are you?

What are your goals for this experimentation?
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Re: Lets Talk Column Packing

Post by mash rookie »

Hi Hooch,
The goal is Column efficiency. Highest possible fractioning at highest speed possible.

Having already been there, done that with a flute that will remove water and achieve high ABV but not separate fractions I have been working towards this goal for sometime.

I am enjoying considerable success with my new designs. This thread is meant to engage people on this subject and to consider possible alternatives to conventional materials.

I plan to test with Stainless steel packing. I plan to build a Fire Pit however I see no reason to not use lava rock for packing and may put it on my to do list. It is a natural stone that was formed by magma flows giving it a very porous surface. It is made up of silica and basalt. The red may have a higher iron content but I don’t know that for sure. I do know that it has been used for bio filters and fish tanks for many years. I cant imagine how a rock could leach anything once cleaned.

by rockchucker22 » Sat Jul 21, 2012 11:10 am

There is a guy on ad that uses volcanic rock as packing, as I recall he says it works great. I live in volcanic country and can get as much as my truck can hold for free, it would be great to know just how well it does work.
Interesting Rock. I bought a huge bag for $5. Following my pressure theory possibly we could crush and size it after washing to four different sizes. Finer at the base and getting larger going up the column with coarse on top allowing less resistance to vapor. Hmm
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Re: Lets Talk Column Packing

Post by mash rookie »

Yes. The glass column will teach us much RC. I have to say though that these tests are a major pain in the ass. To do an equipment test I need to split a wash and run consecutively for real comparison. With the speed a four inch column runs you need to do a 10 gallon run for fair comparison of cuts. That means a 20 gallon ferment. To do a wash comparison, ie BW v.s Noodle, I have to run consecutive runs on the same still using the same power settings and cooling flow. If I don’t do that and give them the same rest time, comparisons are worthless. It can make for a long hard day versus relaxing for a couple of hours.

Anybody tried fiberglass packing?
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Re: Lets Talk Column Packing

Post by blind drunk »

The Mighty Odin mentioned using some kind of rock, maybe lava ...
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Re: Lets Talk Column Packing

Post by myles »

IIRC Odin used small basalt stones in his CM column at one point. I am not sure at all about the use of an absorbent or even adsorbent material for use as packing in a column. I know it can be fixed with a longer stabilisation period - but I suspect the packing will retain tails at the end of each run.

Scrubbers do this too but they do not retain as much as a more porous material would do. Most of the commercial packings are innert and non-absorbent. They just provide a big surface area. If using a porous material you might need to modify your operating procedure to "clean" the packing so as to prevent smearing of contaminants through subsequent runs.
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Re: Lets Talk Column Packing

Post by mash rookie »

That could be a very valid point Myles. That might be the limitation of a porous material. Maybe not though. It might be worth testing. It was just something I threw out there.

After my tests with stainless steel wool I am considering something that allows changing density as described above.

Any thoughts about different materials? Throw something out there guys!
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Re: Lets Talk Column Packing

Post by cob »

NcHooch wrote:You're not actually planning on drinkin hooch distilled through lava rock, are you?

What are your goals for this experimentation?
one of the sources of arsenic is lava rock

http://www.greenfacts.org/en/arsenic/l-2/arsenic-2.htm" onclick="window.open(this.href);return false;" rel="nofollow

any cavern tour will tell you that any number of things leach from stone.

the goal is safety.
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Re: Lets Talk Column Packing

Post by mash rookie »

cob wrote:
NcHooch wrote:You're not actually planning on drinkin hooch distilled through lava rock, are you?

What are your goals for this experimentation?
one of the sources of arsenic is lava rock

http://www.greenfacts.org/en/arsenic/l-2/arsenic-2.htm" onclick="window.open(this.href);return false;" rel="nofollow

any cavern tour will tell you that any number of things leach from stone.

the goal is safety.

Cob, I don’t have much patience with those that spew crap but don’t offer positive intellectual input. Arsenic?? WTF?? That link said nothing about arsenic in Lava rock.? Who flipping cares. That is not the point of this post.

Are you suggesting a particular type of packing material? Pros or cons about pressure differentials? Different HEPT’s that different packings provide? Minimum amount of copper necessary in the vapor path? Your fractioning theory? Anything to add that addresses the orignal post?
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Re: Lets Talk Column Packing

Post by Bushman »

MR, this isn't a suggestion for packing but per our discussion on Friday about adding more packing I did a little more research when I got home. And a guy that has built stills for years and sells them for fuel consumption wrote the following:
In most reflux stills there is rarely enough internal surface area or thermal mass to stabilize the alcohol vapors to create the turbulent up and down effect of condensing ethanol dropping down and being reheated by upward vapors and at the same time cooling and stripping the ethanol out of the upward-moving vapors. A reflux column needs to be internally packed with a thermally stable packing material.
This is not new information to you but just helps solidify what you already knew!

In the past many members suggested that you need to blow into the column to make sure it wasn't over packed when using scrubbers. I am of the mind we need a better way to measure our packing and even though I am happy with the results we got on Friday I am going to take your suggestion and add more packing but before I do I am going to do a similar experiment as you are with two identical runs. One with the current packing and then I plan on adding 1/2 again as much packing to measure the results. Without the glass column I will only be able to measure how it performs without seeing what is going on inside. Good luck on your journey and while at the canal this week I will try and do some more research in this area. Found one paper on rocket fuel testing of different surfaces but it was way over my head.
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Re: Lets Talk Column Packing

Post by mash rookie »

His statements go right to my thinking. My next tests with the fine stainless steel wool will push the line on density. My difficulty is in measuring where that line is without a water column gauge on my boiler. If I had that info from my recent test it would give me a base line to work from. I can learn from observation of refluxing, power in, take off rate and ABV but don’t have that final piece of knowing when I have defeated the packings ability to fraction.
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Re: Lets Talk Column Packing

Post by mash rookie »

After considering my previous post I realize that I could be running tests for months collecting data and interpreting it if I try to add pressure tests in to the mix. I have decided that All packing tests will be done with pressure consideration. Every media will be structured for decreasing density going up the column. That will ensure that what pressures if any will decrease with elevation leaving vapor volume and speed primary considerations.
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Re: Lets Talk Column Packing

Post by rumbuff »

Okay, this might sound a little crazy, but bear with me. If the whole point of refluxing is to have liquid "scrub" the vapors, wouldn't something that atomized the liquid on the way down be the equivalent of huge surface area interaction? If you had a small tank after your reflux condenser, and instead of plates or bubble caps or packing, had it returned through something like a small HVLP spray nozzle? It would add a small amount of pressure and volume before the condenser, so you'd need to increase it's length, but for a small addition of air, you could have alot of interaction? I would imagine it would have a good temperature gradient as well?
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Re: Lets Talk Column Packing

Post by mash rookie »

f the whole point of refluxing is to have liquid "scrub" the vapors,
That is not what is happening Rumbuff.

The term “reflux” is loosely defined as re-distillation for enrichment purposes of alcohol vapor coming off the still. Although most basic stills enjoy some passive reflux when run very slow, reflux most often it is achieved by means of a reflux condenser of some sort. Cold finger, coil or dephlagomater.

There would be no advantage in spraying liquid on or into packing as it would condense into droplets immediately or vaporize.

The evaporation cycle (distillation) is happening at the surface of the liquid at a plate or droplet, that coats a piece of packing. The interaction that is doing the work is what your naked eye can not see. When watching refluxing in action you see liquid dripping down from above like rain. The real action is taking place as the liquid evaporates as it is falling and touching packing or plates. Invisible to the naked eye.

The key to fractioning (separation of alcohol partial pressure compounds) is the repeated evaporation cycles. Refluxing. Done correctly or well, cuts are very pronounced and collectable hearts are much greater. Did that make sense?
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Re: Lets Talk Column Packing

Post by rumbuff »

Ya, that makes sense. I was thinking that the evaporation would happen on the surface of each individual droplet, without any packing present. Thanks for clearing it up tho, like I said, I thought there was a reason it wasn't done, just throwing it out there :)
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Re: Lets Talk Column Packing

Post by mash rookie »

I guess nobody has any wild ideas about what could be used for packing. Walnut shells, sea shells, charcoal, jellybeans?

I am going to order the stainless steel wool today from Grainger. I have some UJSSM and BW working for my next tests. If there is enough to work with in the $108 roll I will pack up my six inch column and see how she runs.

Denisity will be recorded in weight per cubic inch.
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Re: Lets Talk Column Packing

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mash rookie wrote:I guess nobody has any wild ideas about what could be used for packing. Walnut shells, sea shells, charcoal, jellybeans?

I am going to order the stainless steel wool today from Grainger. I have some UJSSM and BW working for my next tests. If there is enough to work with in the $108 roll I will pack up my six inch column and see how she runs.

Denisity will be recorded in weight per cubic inch.
Pull out the calculator!

If you give me the height of your 6" column that you pack it too, I can quickly get a volumn analysis on my CAD program then all you have to do is weigh it. :D
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Re: Lets Talk Column Packing

Post by mash rookie »

Thats easy enough BM. R sqd X pi X hieght. You have seen my digital scale. It is accurate to one thousandth of a pound.

I forgot to order the steel wool yesterday but will this morning.
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Re: Lets Talk Column Packing

Post by frozenthunderbolt »

mash rookie wrote:I guess nobody has any wild ideas about what could be used for packing. Walnut shells, sea shells, charcoal, jellybeans?

I am going to order the stainless steel wool today from Grainger. I have some UJSSM and BW working for my next tests. If there is enough to work with in the $108 roll I will pack up my six inch column and see how she runs.

Denisity will be recorded in weight per cubic inch.
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Re: Lets Talk Column Packing

Post by Stilly »

MR, you might want to check out Riku's board for his finding on SPP. He seemed pretty well convinced it was the act to beat after running tests. He also had some discussion on AD on his findings.

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Re: Lets Talk Column Packing

Post by mash rookie »

I have heard that it is the cats meow Stilly. I watched the video on how to make it that the Russian guy posted. Is anybody making it in the US? I just might have to build a machine. I forgot to order the damn wool again yesterday. Its on my list for Monday.
Speaking of volcanic rock, what about discs of pumace stacked with space between each disc???
What is a pumice disc Rock?
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That might work FB
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Re: Lets Talk Column Packing

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mash rookie wrote:I have heard that it is the cats meow Stilly. I watched the video on how to make it that the Russian guy posted. Is anybody making it in the US? I just might have to build a machine. I forgot to order the damn wool again yesterday. Its on my list for Monday.
I wish I knew where to get it in small quantities in the US. There is also discussion about it on the Yahoo Distillers Group if you hadn't seen that. Keep us posted if you find any!

cheers
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Re: Lets Talk Column Packing

Post by myles »

That comment about vapourising of reflux is worth looking at again. There are discussions concerning the effectiveness of the column packing relating to the vapour speed, that deal with droplets being suspended by or transported upwards in, the vapour column.

Thermal stability of the packing is also valid. Insulation of the column immediately improves the stability of the typical packed column with reflux condenser. One of the "problems" with the SPP is the increased thermal mass. Too much retained thermal mass might not be ideal when it comes to the transitions between the phases.

I don't understand why the SPP is as efficient as it seems to be. Conventional practice is to run the SPP at high vapour speeds, with the packing in a condition most folks would consider to be "flooded". There is no doubt that it works very well (simmilar results with about 1/3 of the height when compared to scrubbers), but it seems to be that all the action is taking place in the last few inches of packing.
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Re: Lets Talk Column Packing

Post by rubber duck »

Some of the guys on the Russian forums are using lava rock and apparently they're getting really good results. It makes sense, you could get good density and it's extremely porous.
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Re: Lets Talk Column Packing

Post by Prairiepiss »

If Odin was around he could comment on using rocks. :problem:
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Re: Lets Talk Column Packing

Post by Bushman »

Stilly wrote:MR, you might want to check out Riku's board for his finding on SPP. He seemed pretty well convinced it was the act to beat after running tests. He also had some discussion on AD on his findings.

cheers
stilly
Riku is very high on SPP and with his tests on lava rock he felt that the problem was vapor-liquid contact thinking that not much was happening inside the rock. I have not yet read his books but would be interested to see how these tests were performed. In regards to density of lava rock or where they crushed, how were they packed, etc.
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Re: Lets Talk Column Packing

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rubber duck wrote:Some of the guys on the Russian forums are using lava rock and apparently they're getting really good results. It makes sense, you could get good density and it's extremely porous.
The Russians are very ingenuitive people and quite serious about their neutral. My Russian friends taught me to drink vodka Russian style.

I was just throwing that out there after looking at its surtface but may have to give it a go as a direct comparison to my steel wool test.
I had to go buy a second $5 bag of lava rock to fill my fire pit crucible. The good news is that my fire pot is working great! I plumbed it with natural gas.

I would not use it directly from the bag. The lava rock that I have is about 1” diameter. It would have to be crushed, washed and sized through screens.
I would want to start with ¼” diameter to achieve good density. I don’t think at that size we will have to worry about what is happening inside the rock BM. Its porous surface is what we are after. Thermal transfer may be some issue Myles but I think that changes are happening slow enough to not be affected drastically. I have 20 gallons of BW that can run this week. If I get both packing protocols ready I should be able to do consecutive 10 gallon test runs in the glass column.

I believe that the SPP works because of density. I kind of question those vapor speeds Myles. It just does not make sense that they could push that much through it at that density. There just wont be enough room for that volume. The unique shape of it allows for tight compaction without collapsing on itself unlike a spring would. That may be a problem with my efforts using stainless steel wool. I will weave a stiff wire structure through it for support.

After hearing about SPP and reading about other pour in packings, I want to push the limit on density to learn the ballance point of density,vapor speed and take off rate.
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Re: Lets Talk Column Packing

Post by Odin »

Interesting read up so far!

I just took a trip to the Hungarian / Croatian border. In a hunting house with family in law. And 5 liters of geneva, 3 liters of apple pie and some Limoncello. So it is a bit hard to remember what we did exacly. I do remember we got utterly lost while touring the forests in Mitsubishi Pajeros. But we got out, and here I am.

The rocks I use are basalt stones. Not lava. Not porous at all. What got my thinking going was that the vapour speeds I get with this dense, low surface area are so high, and still I can get to 96.5% abv.

Reading up on SSP, I feel (but cannot proof) that vapour/liquid exchange works differently in a situation where gasses flow freely and meet droplets of reflux on the way (say with scrubbers) and a situation where gasses bubble up thru liquid (a flooded/semi-flooded packing like spp). To put it in another way: with the HD regular explanations on achieving high abv/hetp I couldn't explain my results. My surface area is low, my vapour speed off the charts ... but it works.

The outcomes I get with my rig seem to be more easily explained by looking at what happens with spp and (semi) flooded re-distillation cycles.

A question for MR. Just to get things clear. MR, you say you couldn't achieve perfect separation with your flute. Even with a reflux line and all. But what I am curious about is what is your definition of perfect separation? Do you mean a perfect 96.5% result? Or the best separation of heads from hearts from tails? Or that you achieve (or not yet) a perfect neutral from - say - a UJ beer?

I ask this, because I think that different things can happen (or at least happen to me). For instance with my CM fractionating rig I hit 96.5% every time. From a wash of 9%, or from low wines of around 40%. Both will give me 96.5%, and abv wize I can make the same cuts for heads & tails (relative to the wash/low wines size that is distilled). The first approach will give me nothing close to a vodka though. At least not when I use an UJ beer as a base. It will give me a very light whiskey. Eau de Vie might be the best description. So even a " perfect" 96.5% leaves me with some taste. Strange.

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Re: Lets Talk Column Packing

Post by mash rookie »

Hi Oden,
I cant speak to your still and in effort to stay on topic of packing I will avoid discussions about my plated flute.
a flooded/semi-flooded packing like spp
Oden, SPP is not meant to be flooded even in part as that would defeat evaporation cycles where flooded.

Here are some excerpts from an SPP makers conclusions and recommendations.

1. Minimum resistance for vapor. Packed column working in film mode.
The flow of the film reflux unseparably, laminar. Flow regime - waveless.
According to experimental data, the optimal rate of steam is about 1.5 m /
s, ie very little. This means that the cross-section of the column should be free to
the maximum.
2. With a minimum of volume our packing should be characterized by a
maximum surface. We know that the interaction occurs at the interface between
liquid and vapor.

Q-3 What can we obtain, using spiral-prismatic attachment.
Consider a column of 40 mm in diameter. Its cross section is equal to 12.56
cm2. Let us remember that figure.
Let’s see what facilities we will be able to work using a variety of packings,
if the optimal rate fo vapor is 1,5 m / s, and at 1 kilowatt heater power produce around
45 liters of vapor per minute, or 750 cm 3 / sec.
If the column is empty, then we are at a speed of 150 cm / s in 1 second
would have let through the cross section of the column 1884 cm3 of vapor, which
corresponds to the power of 2.51 kW.
At this stage, are visible benefits of properly made spiral - prismatic
packing. It is, on average, leaving 86% free cross section of the column, that is, allow
us to work with a power 2.51 x 0, 86 = 2.15 kW.


Some things noted in his essay were thermal conductivity, (mentioned by Myles) glass packing and surface texture or finish.

Static retention capacity of spiral-prismatic packing, etched properly, only
slightly inferior to the static retention frosted glass
[/quote]
It may be that lava rock has a down side of poor thermal conductivity but an upside of the porous surface allowing greater static retention.

Reading his essay has added another test to my list. Glass. I have plenty of glass to work with. I have tried it before on two inch but did not understand some of the goals. Can anybody loan me a cement mixer? After crushing and sizing threw screens it will need to be surface treated. Tumbling it with silica sand should leave a frosted matte finish for static retention. This is a large consideration with any packing. I acid etch my wire packing now. Shinny bad. Dull good!

One thing I know for certain. Some things will be different with the larger diameters. While some packings will not work on larger diameters, protocols should remain similar. No reason to re invent the wheel. I will need cold measure testing for comparisons and may build a 12' testing pipe.
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Re: Lets Talk Column Packing

Post by Odin »

Sorry if I trailed off topic. Thought I read somewhere in the beginning of this thread a reference to the efforts you made before, using a flute but not achieving perfect separation. Maybe I am off? Maybe it was not the point you wanted to make?

Still looking for a definition of " perfect separation". Think it is important. If the goal is to achieve it by talking about column packing. I will try to put some thought into it.

I also think SPP has something to do with semi-floodedness. Some say it does not, some say it does. Reason I think it does, is because we need a new environmental circumstance to be introduced. Since, given normal environmental circumstances, the possitive effects of SPP cannot be explained. It's evaporation square cm's are less. It takes up more space, so vapour speeds need to be reduced. Twice. For the smaller available space for gasses. And for the fact SPP has less evaporation square cm's. Or at least, that would be the outcome of all the calculations using the traditional "gass meets liquid drops" / HETP" theory.

So using SPP would mean a column at least 4 times longer?

No. The outcome of all the tests show a shorter column can be applied and higher vapour speeds (and take off rates) can be used. Still giving you " perfect seperation" (in absence of a definition: 96.5% all the time, the same heads/tails compression as with "normal" packing, fastest take off speeds possible, with minimal taste transfer).

If all other things stay the same, what has changed?

The smaller space for gasses (or liquids) to gather or travel thru. And the heat (or cold) retention of a more dense packing. Faster vapour speeds in themselves would not explain this. So what does? The only thing varying here is ... heat retention of a more dense packing. But does density and heat retention affect gasses? If they cool, they just phase change back to liquid. But does heat retention have an affect on liquids? Oh yes it does!

It cools the liquids, and holds/traps liquids, thus enabling a (semi-) flooded environment where exchange between gass bubbles and liquids take place. Look at it like a thousand little bubble caps. Or a hundred thousand. Working with liquid and gasses, but on a close to microscopical seize.

Okay, that is my contribution. Off to other topics for now!

Odin.
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