Glass Marbles for Reflux Column Structured Packing

[rad14701]

Rad:
I sure hope you don't have a cat

No, but who the hell has pets that get on kitchen counters anyway...??? I never have and never will...

That picture serves as an example of how a small scale setup can produce exceptional spirits... That collection point is far too high, even for me, and things need to be modified in the very near future... It's far mare stable than one might first assume, however... I'm still working on cleaning the hoard out of the basement so I can have a dedicated stilling area... My father never got rid of anything...

[rad14701]

Makes me wonder about tempered glass shards, they have large surface area and are all they same size basically, they would pack well and be very cheap(free)

You could give them a try but I seem to recall that the flat sides cause them to stick together more than expected, impeding vapor flow followed by choking and flooding... But it would depend on the tempered glass, I suppose...

[Boda Getta]

" pets that get on kitchen counters anyway...??? I never have and never will..."
Fully agree there; I am amazed by people to allow their pets to lick them on the mouth. I have a personal rule: Never allow a pet who can lick his own butt-hole, lick me on the mouth.

BG

[mash rookie]

Hooker, by disregarding Rads formula and using flattened marbles you change the game rules.
I doubt seriously you will achieve any satisfactory results.

While a smooth hard surface is not as affective as one that provides surface tension and “cling” Rad has corrected for this with greater throughput and higher reflux ratio thereby re distilling his spirits many more times. The larger marble allows for additional space for vapor and refluxed or condensed vapor to fall. Matching surface area, type, speed, and reflux takes practice with any type.

He has found a sweet spot where the marbles work. With a tighter packing vapor speed will have to be reduced to avoid choking. Nice work Rad.

Every different packing I have tested, like every different still tested required different operating procedures. (usually with a large learning curve)

Have a great day Guys!

[ga flatwoods]

Great to see you post Mash Rookie! Thanks for your insight!
Ga Flatwoods

[ga flatwoods]

Anyone tried with comments to make?

[rad14701]

I have more wash to be run through the marbles... Not sure if I'll get a chance to run that wash before I run off my rum or not... Interested in hearing the results anyone else has had...

[Bagasso]

Had I slowed down my take off rate I may have been able to further compress the tails but I have found that it's easier to just increase the heat input because the take off rate drops as soon as the transition from hearts to tails occurs...

Any idea if it also does this between heads and hearts?

[rad14701]

Had I slowed down my take off rate I may have been able to further compress the tails but I have found that it's easier to just increase the heat input because the take off rate drops as soon as the transition from hearts to tails occurs...

Any idea if it also does this between heads and hearts?

Yes... I generally start out with a slower take off rate of 4 - 5 drips per second for my first jar which collects foreshots and early heads... After that, starting with the second jar, I increase the take off rate to be a steady stream, rather than drips, and collect at a rate of 125ml (4oz) every 4 - 5 minutes... When refluxing low wines I can even run slightly faster for the hearts... I just did two runs on Saturday and collected the tails in normal reflux mode for the heck of it and the collected tails were actually cleaner than when collecting in pot still mode with the needle valve all the way open...

[bearriver]

Ordering these "peewee" marbles now: https://www.moonmarble.com/p-2087-clear-peewees.aspx" onclick="window.open(this.href);return false;" rel="nofollow

These clear marbles are approximately 12mm or 1/2" in diameter. They are sold by the pound or in an 1000 count bag. The 1000 count is an approximate amount and can weigh anywhere between 5 and 7 pounds depending on the color and size of the marbles.

Hopefully they will get here before I do my next deal here in a few day, so I can test them. I have no Idea how much to get, so will start off with one bag of 1,000. Math wasn't my strongest subject...

[thecroweater]

Ihad a thought about improving the performance of marbles a couple of years back but never actually tried it or asked if others have. My idea was to put the marbles in a concrete mixer with fine gravel and a bit of water and run it until such time as to scuff the surface of the marbles. I was thinking this would improve their "wettability" no end and therefore cut down the amount of reflux cycles required for the same desired result obtained by un-modified marbles , Just a thought

[rad14701]

Ihad a thought about improving the performance of marbles a couple of years back but never actually tried it or asked if others have. My idea was to put the marbles in a concrete mixer with fine gravel and a bit of water and run it until such time as to scuff the surface of the marbles. I was thinking this would improve their "wettability" no end and therefore cut down the amount of reflux cycles required for the same desired result obtained by un-modified marbles , Just a thought

Craft stores sell glass etchant which would accomplish the same result... But your rock tumbler method should also work...

[Roddy]

Ihad a thought about improving the performance of marbles a couple of years back but never actually tried it or asked if others have. My idea was to put the marbles in a concrete mixer with fine gravel and a bit of water and run it until such time as to scuff the surface of the marbles. I was thinking this would improve their "wettability" no end and therefore cut down the amount of reflux cycles required for the same desired result obtained by un-modified marbles , Just a thought

The key element in all of this is the AREA of contact between the surface of the liquid and the passing vapour.

Increasing the surface area of the liquid surface bearer medium (e.g. marbles) at the bottom of the liquid layer (not the surface which meets the vapour) is of no consequence.

On the other hand, using smaller diameter marbles can provide a thinner liquid layer and an increased area of liquid/vapour contact (per unit mass of marbles and unit feed of liquid), so this would indeed improve the flux of the molecular exchange - alcohol evaporating out and water condensing in.

But after a point (see many references to packed columns "choking") gravity cannot remove liquid fast enough and vapour passageways, upwards, get clogged with liquid and produce the expected Physics chaos.

This is most easily understood if you forget all about "boiling" once vapour is passed out of the pot. Fractionation is about molecular exchange. And that occurs only through the area where the liquid and vapour phases contact each other.

No boiling occurs beyond the pot.

[thecroweater]

there are more things t play than just the surface area, you would need to try it before making statements like that and my money would be on it making a profound difference

[Roddy]

Maybe, for you.
But my money is on Science and Irving Langmuir (Nobel prizewinner).
He showed, categorically, that fractionation in a reflux device (plate, packed column, spinning band etc) takes place ONLY via the area of contact between the liquid and vapour phases. All industrial and other (including HD) stills depend on the absolute nature of the relationship he published. No ifs, no buts.


I do not make such statements based on guesswork, as you imply.

[DAD300]

Roddy,

Large object vs smaller object, say they are they same shape, same material, same surface...the smaller object has a thinner surface layer of liquid? Serious question...

I see the smaller object packing tighter and making less void for vapor, thus slowing vapor and creating more interaction.

[thecroweater]

Ok so lets assume that nothing at all about different strata, still design , vapour density or speed has any effect , only surface area. Cool , how many times larger do you think the surface area would be on a completely scuffed up marble as opposed to a relatively smooth one. I'm aware its a "how long is a piece of string" question but it is suffice to say it would have many many many times more surface area so on surface area alone one can assume that it will improve the reflux performance by many times
@ Dad Yes I guess if you were willing to run the still very much slower though a denser packing it would have that effect but most people aim for a quicker run while maintaining the quality they desire

[Roddy]

Roddy,

Large object vs smaller object, say they are they same shape, same material, same surface...the smaller object has a thinner surface layer of liquid? Serious question...

I see the smaller object packing tighter and making less void for vapor, thus slowing vapor and creating more interaction.

Good question/observation.
The ratio of the surface area to the volume of a sphere grows rapidly as the radius is decreased.So if an equal volume of liquid is applied to two systems, one of marbles, say 20mm in diameter, and the other is say 10mm diameter, the surface area (of equal weights) of the smaller marbles is TWICE the surface area of the larger ones (2513 vs 1257 sq mm). So the liquid layer will indeed be half as thick, all other things not interfering with that calculation.

But alongside the surface area "benefit", the available void-space does indeed diminish dramatically too, as you clearly envisage. It pays to remember that this void-space serves not only as a route for vapour to pass upwards, it also has to accommodate any liquid falling downwards which cannot flow over the surface of the marbles quickly enough to keep up with the downward liquid feed rate.

So, yes.... once we learn that the molecular exchange takes place solely at the liquid/vapour contact area, we can then, and only then, start to investigate and manage all of the parameters which can spoil the ideal case of a constructed, suitable contact area. Like doing the best we can to make the liquid flow evenly over the packing (Surface Tension problems which may be helped by surface etching), or being able to move liquid (or vapour!) as fast as we need to (viscosity problems).
It's all a bit like "putting the cart before the horse": Ignoring the fundamental process of exchange is bound to lead to false assumptions and poor results overall.

[Roddy]

Ok so lets assume that nothing at all about different strata, still design , vapour density or speed has any effect , only surface area. Cool , how many times larger do you think the surface area would be on a completely scuffed up marble as opposed to a relatively smooth one. I'm aware its a "how long is a piece of string" question but it is suffice to say it would have many many many times more surface area so on surface area alone one can assume that it will improve the reflux performance by many times
@ Dad Yes I guess if you were willing to run the still very much slower though a denser packing it would have that effect but most people aim for a quicker run while maintaining the quality they desire

See my previous response.
The surface area of a "scuffed up" marble will be higher than a polished one of otherwise similar dimensions, of course.
Which may facilitate a better spread of liquid over its surface and thus bring the active contact surface area (liquid-to-vapour) closer to the designed ideal.
Many other factors can also reduce the designed ideal.
But no other factors are able to improve on that designed ideal, which is testament to the accurate and concise nature of Langmuir's Equation.

Understanding and acceptance of Langmuir's Equation isn't mandatory, but denial of it's importance as the necessary foundation for any reflux-based fractionator is about as useful as declaring that the Moon is made of cheese.

[bearriver]

Many other factors can also reduce the designed ideal.
But no other factors are able to improve on that designed ideal, which is testament to the accurate and concise nature of Langmuir's Equation.

Understanding and acceptance of Langmuir's Equation isn't mandatory, but denial of it's importance as the necessary foundation for any reflux-based fractionator is about as useful as declaring that the Moon is made of cheese.

What? I just looked that equation up, and didn't learn anything practical. I guess its above my pay grade...

On a side note Odin claims that he does not etch his SPP for better performance. So whatever is going on there, may also apply to marbles. I wouldn't think etched marbles would perform any better/worse without collecting real world data. You know what they say about assumptions...

[Brutal]

Roddy, have you ever run marbles in a still?

[SoMo]

Rad in my new CM column what would be the best way to secure such a medium in the column? Seems without some major restraint the medium would be hard to keep in place. 50 inches of column to fill.

[MichiganCornhusker]

OK, first of all, I'm WAY out of my pay grade and in over my head on this one. But, I am trying to learn more about reflux so that someday I might build a column still. This thread seems to be generating a lot of current, useful info about packing material.

Roddy, you seem to be suggesting that if we all just bow down to Irving (Nobel prizewinner), and pay attention to surface areas, that's all there is to it, no more to think about, no ifs, no buts. I think most folks here would agree that a key element of reflux is the area of contact between surface of liquid and passing vapor, but as you begin to maximize that area, then the key areas shift to other factors, such as reduced vapor passageways, rates at which you can run the still, etc. As Croweater suggests, there are many things in play when trying to maximize efficiency in a reflux column. I don't think anyone here is trying to improve on, or trying to surpass Mr. Langmuir's design ideal, we're just trying to get as close as possible to it.

Roddy suggests:
"once we learn that the molecular exchange takes place solely at the liquid/vapour contact area, we can then, and only then, start to investigate and manage all of the parameters which can spoil the ideal case of a constructed, suitable contact area."

Agreed. Even I, a reflux noob, am prepared to accept that exchange happens at liquid/vapor contact area. So, now, and only now, am I prepared to investigate all the other parameters.

That's why I started following this thread in the first place, because Rad started experimenting with a packing that seemed to have been dismissed over the years. This thread seems to be getting a lot of response on the hows and whys of how various packings work, and how the efficiencies can be improved. It has at least really helped me get a better understanding of how the reflux columns work, and I'm grateful for all the back and forth, guys, thanks!

[DAD300]

So, can we agree that there is a relationship between surface area, liquid hold up and column void (area for vapor and reflux to travel through)?

I think so...and there is the balance we've found in SPP. The physical size of the SPP determines the void as smaller SPP packs tighter.

The surface of the packing, when rough (etched SPP) can retain more liquid.

non-etched and etched SS Wire

This is a very simple experiment of etched and non etched surfaces, but it shows that etched holds more liquid than non.

But this all happens in relationship to the other elements of the packing. In fact it has been proven that etched SPP can be detrimental to the BALANCE of the other qualities of a packing. Too much liquid hold up can interfere with the downward travel of the reflux and flood the column.

Now we might assume a flooded column is bad, but again experience with SPP has shown that it is at it's optimum when the column is flooded and the vapor has to travel within the liquid and bouncing off the packing surfaces. There are videos of this state.

[straight_shot]

While the picture obviously shows that the etched side holds more liquid, it's not from the etching, but from the fact that the pipes are not bent equal and the etched side is almost flat. Not sure if it was intended as a joke, or I'm just missing something.

[rad14701]

While the picture obviously shows that the etched side holds more liquid, it's not from the etching, but from the fact that the pipes are not bent equal and the etched side is almost flat. Not sure if it was intended as a joke, or I'm just missing something.

That was also my first thought... Identical coils would give a more realistic result...

[straight_shot]

While the picture obviously shows that the etched side holds more liquid, it's not from the etching, but from the fact that the pipes are not bent equal and the etched side is almost flat. Not sure if it was intended as a joke, or I'm just missing something.

That was also my first thought... Identical coils would give a more realistic result...

Absoloutely......kink a pipe into a V and see how much it holds, with etching and without.....not much. The radius of the bend or lack of will have an effect on how much liquid will hold. Unless I'm wrong.....which is always a possibility.

[rad14701]

Rad in my new CM column what would be the best way to secure such a medium in the column? Seems without some major restraint the medium would be hard to keep in place. 50 inches of column to fill.

You have several options... A small amount of scrubber might hold that much weight... Or a sink drain sieve... For my small column I use a length of heavy copper wire bent into a zig-zag pattern that rests on a lip where the copper slip joint is soldered onto my stock pot lid...

[SoMo]

Ok thanks I figured something like that but the possibilities are endless.

[lampshade]

Do marbles prevent channeling (reflux running down the side of the column, instead of in the packing)? I know that can be an issue with mesh/scrubbies.