Glass Marbles for Reflux Column Structured Packing

[Bobbywolf]

Michaels craft store. They have lots of locations, hopefully one by you. They are sold as decrative beads and are round, clear and 7/16 in diameter. 1kg tubes.

[Desvio]

Depending on where you are (US or Canada?) and if you have Amazon Prime, these were a pretty good deal for quantity and price.

https://www.amazon.com/gp/product/B00MV ... detailpage

Ordered two packages of them, and they are working pretty good for thier size.

[still_stirrin]

Here's where I got mine: http://www.hobbylobby.com/Floral-Weddin ... les/p/3504" onclick="window.open(this.href);return false;" rel="nofollow

And at $3USD for 2 lb., the price is very reasonable. Grab a couple of bags for when they crack, which they will...they're glass.
ss

[Klein]

Here's where I got mine: http://www.hobbylobby.com/Floral-Weddin ... les/p/3504" onclick="window.open(this.href);return false;" rel="nofollow

And at $3USD for 2 lb., the price is very reasonable. Grab a couple of bags for when they crack, which they will...they're glass.
ss

Has anyone compared different size marbles? With the size difference compared to the 7/16" (11.1mm) bobbywolf uses.

I'd love to hear if guys think it would make much of a difference.

[Bobbywolf]

Just make sure you wash them well in a bucket of hot soapy water. Mine had an oily sheen initially.

[greggn]

> Just make sure you wash them well in a bucket of hot soapy water.


I soaked mine in a pot of heads followed by a boil in clean water. They came out squeaky clean.

[casper the Irish]

If bluefish is getting better result from scrubbies (given he needs to do the straight comparison Rad asks) could a factor be the dispersal patterns. Scrubbies spatter liquid randomly, regular marbles are patterned. Perhaps those unsorted marbles of various dia will improve the diffusion of distillate in vapour

[FullySilenced]

@RAD14701 How many 7/16" marbles will it take to fill a 4" x 24" column?

if you could how many 3/8" ones as well i may want to go smaller? just considering

trying to place an order for a few to play with


i calculated 2408 1/2" marbles to fit in same size column but am not sure if my numbers are close even.... i said to myself "I bet Rad would know just from memory!"

happy stillin,

FS

[700G]

@RAD14701 How many 7/16" marbles will it take to fill a 4" x 24" column?

if you could how many 3/8" ones as well i may want to go smaller? just considering

trying to place an order for a few to play with


i calculated 2408 1/2" marbles to fit in same size column but am not sure if my numbers are close even.... i said to myself "I bet Rad would know just from memory!"

happy stillin,

FS

Here's how my 5/8" marbles worked out in a 4" column:

5" of marbles in a 4" column = 3.25lbs. 308 marbles

[FullySilenced]

@700G Thank you

BTW The equation for this was developed over 400 years ago. It is a favorite classic physics advanced geometry problem.

It took 400 years to verify and prove the theory.

Was bugging the **** out of me for the last couple days, but have gotten it down to hand grenade and horse shoes close.

Happy Stillin

FS

[rad14701]

@RAD14701 How many 7/16" marbles will it take to fill a 4" x 24" column?

if you could how many 3/8" ones as well i may want to go smaller? just considering

trying to place an order for a few to play with


i calculated 2408 1/2" marbles to fit in same size column but am not sure if my numbers are close even.... i said to myself "I bet Rad would know just from memory!"

happy stillin,

FS

I'm using 5/8" marbles and "should" have a formula for various size requirements and it seemed fairly accurate... I'll have to hunt around because I'm not sure if the spreadsheet file is on a local machine or on my server... That's one calculation I can't pull off from memory...

Edited to add: I've only been able to find a formula from early on in my research and with a little tweaking was able to come up with a range off 4477 - 5000 7/16" marbles to fill a 4" x 24" column section... But that number sounds high to me so I'll try to refine the formula... Even the scientific math wizards seem to have a tough time with this one due to some of the variables involved...

[thecroweater]

If you take the assumption that the marbles are the same, shaken down the voids should be the same. If the marble size the height and the diameter are known it should not be very difficult to calculate. Even if they do not precisely stack each layer will deviate by the same percentage, worse case scenario there will be a formula for that maximum that will fit

[rad14701]

@RAD14701 How many 7/16" marbles will it take to fill a 4" x 24" column?

if you could how many 3/8" ones as well i may want to go smaller? just considering

trying to place an order for a few to play with


i calculated 2408 1/2" marbles to fit in same size column but am not sure if my numbers are close even.... i said to myself "I bet Rad would know just from memory!"

happy stillin,

FS

My calculation, derived by using online calculators and a simple calculator, came out to ~2575 for 1/2" marbles in a 4" x 24" column... However, that number might be high given the fact that I used the 4" OD as the ID in one calculator... With an actual ID that number would most likely drop...

That same method of calculating resulted in ~3465 7/16" marbles in that same column...

One thing to note here is that these numbers are not optimized by taking into account the fact that there is a percentage of nesting between layers and potentially different numbers of marbles per layer due to said nesting... Worst case scenario is that more marbles may be required to completely fill to 24"... It might be practical to buy a few more than you think you need - and a slingshot...

[T-Pee]

It might be practical to buy a few more than you think you need - and a slingshot...

K.I.S.S.

tp

[Fills Jars Slowly]

This is a run report comparing marbles to stainless scrubbers for one particular still design and one particular set of initial conditions.

I decided to build a Condenser Controlled Vapor Management (CCVM) still similar to many designs seen on this site. It consists of a 2” copper pipe for the column with a 2” takeoff tee above it, a Dimroth style reflux condenser made from corrugated stainless steel tubing above that and a 2 foot long Liebig as a product condenser. The column is about 40 inches long up to where it meets the bottom of the tee and is meant to hold 36” of packing. Here it is in action dripping product into a proofing parrot’s beak:

For my initial cleaning runs, I made up a still charge of 1 liter of 95% abv Everclear and 8.5 liters of water for a total of 9.5 liters at 10% abv. For the first run with alcohol after the water and vinegar runs, I packed 3 feet of the column with stainless steel scrubbing pads, and for the second run (same still charge with the first run distillate dumped back in the boiler) I took out all but the bottom couple of inches of scrubbers and replaced them with 14mm diameter marbles.

The first run with scrubbers produced 95.6% abv when the hydrometer reading is temperature corrected:

The second run with marbles made the same thing:

Due to the angle of the photos and such, it may be hard to tell, but the readings between the two runs are just about exactly the same, though I was running the marbles just a bit faster, maybe a liter per 30 minutes rather than a liter per 40 minutes. I could probably have run both even faster and stayed close to azeotrope, but it was my first time running this still so I didn’t push it. This is what the output looked like:

The main differences between the scrubbers and the marbles are:

• The scrubbers are a pain to get in and out of the column. I resorted to a fish hook taped to the end of a mop handle to remove them. They also tangle up with one another and I cut my finger pulling them apart.
• Marbles are easy to get in and out of the column. I scooped them in with a plastic cup and poured them out into a bucket when I was done.
• The marbles make a slight clattering noise near the top of the column when running, the scrubbers are silent.
• If you buy the scrubbers at retail (Home Depot or grocery store) they are more expensive at about $2.50 for a three pack, with 24 total scrubbers needed. The marbles are $3 for 2 pounds at Hobby Lobby. It took about 5.5 pounds to fill my column. So it takes about $9 worth of marbles and about $20 worth of scrubbers. However, I see that an online restaurant supply advertises stainless scrubbers for $4.39 a 12 pack, so shipping aside, that is competitive with marbles.
• The marbles will last basically forever (a few break here and there), while the scrubbies degrade with use.
• The marbles are super easy to clean, while the scrubbies are not.

Since this was a cleaning run, I don't have any comment on any difference between the taste qualities between the two runs. Here are the marbles I poured out of the column:

Conclusion? In a 2” diameter CCVM with a 3 foot packed section, both marbles and scrubbers produce azeotrope from a 10% abv still charge. For me, a couple of scrubbers in the bottom to retain the packing and the remainder as marbles is the perfect balance of ease and effectiveness. Note that my experiment does not prove that marbles have a HETP equivalent to the scrubbers, just that 3 feet of packed 2” column is a enough for both materials to produce azeo. Further experimentation reducing the height of the packing could well show that the scrubbers have a lower HETP, as theory indicates.

I also have lava rock, but have not experimented with that yet. Marbles are so clean and easy that I might choose them over other packings unless I really needed the smallest HETP or I am running a large enough column that the weight becomes a problem. I have used them in my 4” flute column instead of plates and over plates and it gets pretty heavy but not undo-able. That setup doesn’t achieve azeotrope at the takeoff rate I usually run, but it does make pretty decent neutral at a high output rate.

[still_stirrin]

Fill Jars Slowly,

I'm a "believer".

And...a "user".

Great assessment and summary. Thx.
ss

[KingE]

FYI I figured hobby lobby 2 pound bags would be 3 bags per foot for my 3" column. It's a bit better than that. 14" per 3 bags.

[masonsjax]

I bought 5 bags for my 3" x 30" column and had maybe a half pound left over.

[pounsfos]

So for people wanting to know.

We have basically concluded that
1. the HETP of marbles isn't as bad as we thought it was.
2. it could be on par with Pot scrubbers but with advantages such as
a: easier to pack/unpack
b: easier to clean
3. My theory (yet to be proved but a thought for everyone) is that there will be a "perfect size range" marble for different still sizes
IE: to small and it will flood easily, to big and might not get the same HETP value,

More data is required, if we can roughly prove that marbles have a slightly better HETP value, then repacking them over Scrubbers could mean you might get a free plate or 2 extra, and thats always nice.

If people could put in there posts what size marbles they have purchased, and maybe some more experiences with them, we could be onto a winner.

Keep trucking people, you guys are doing well.

and as always, thanks Rad for curious mind.

Edit:Heres a table for conversion for you metric people (myself included)
http://infinityline.net/conversion.htm" onclick="window.open(this.href);return false;" rel="nofollow

[The Baker]

Thanks, I will be interested to see how this works.

Maybe two people with the same 'model' still could distil the same product in the same way, one using marbles and the other using Pot scrubbers...
A great project for two who work together....
Geoff

[joeymac]

I don't really think there's anything to "prove" about scrubbers vs marbles...

I had copper scrubbers in a 36" x 2" column and it produced about 1 L/hr of 94%
I switched to marbles in the same setup and I was able to hold 96% at a rate of 2.5+ L/hr
Marbles had better purity, over twice the production rate, and handled way more power. Still clean tasting too.

[The Baker]

Thanks, joeymac, that's exactly what I wanted to know.

Ordinary sized marbles? Or maybe a bit smaller?

Geoff

[T-Pee]

Marbles had better purity, over twice the production rate, and handled way more power. Still clean tasting too.

The marbles or the distillate?

tp

[Klein]

It was months ago since I have read this thread so I don't remember if it has already been stated.

Just incase anyone wanted to know how much to get.
The 2lb bag of marbles from hobby lobby will fill 19" of 2" copper pipe.

[pounsfos]

what size marbles you using klein?

so others can share your results

[joeymac]

my marbles are from michaels or hobby lobby and 5/8"

[Klein]

what size marbles you using klein?

so others can share your results

They are the hobby lobby 14mm

[pounsfos]

soo

5/8' is 16mm according to my chart in a previous post. (thanks for the input joeymac!!), rad is using this size aswell, although I believe he started with bigger marble and working his way down.

and klein is using 14mm

I would say this is a good agreed size for a 2' column, and naturally scale the marbles up as column diameter increases (to be properly tested)

from Joeymacs earlier post

I had copper scrubbers in a 36" x 2" column and it produced about 1 L/hr of 94%
I switched to marbles in the same setup and I was able to hold 96% at a rate of 2.5+ L/hr[/color]

from lester on page 2
I was very pleased to be able to take product out at 1:1 RR and the head temperature would still hold steady. This is a big improvement from the 2:1 RR I needed with the scrubbies.
Output rate at middle of the run = 3.5 LPH of 95.6% ABV

Column Type: VM
Column Diameter: 2"
Column packed height = 45"
Packing: Round glass marbles 11.2mm in diameter

so without going to far into testing, it is safe to say, they work better than scrubbers, but It would be fantastic if we could work out the HETP, I think the parent site needs a good upgrade and I believe thats in progress, so beeing able to find out the HETP of all this new and revised packing that is around would be awesome, as a few people have said, you might not be able to get a certain packing in your country, but at least you can have a quick look on the parent site, or these posts, and see what the HETP value of said packing is.

anyway, back on topic, so marble definitely seem to hold their own against scrubbers, I may have to grab some and join in with all the fun you're having collecting data.

[joeymac]

It's more complicated than marbles having a set hetp. Marbles work best when you really throw a lot of power at them and get the top and bottom of the column to flood. If you're not going to drive them hard they won't work as efficiently. Essentially, the hetp changes with more power and column foooding state... so there is no set number. Search here about marbles and the aquatic environment in the column regarding the different zones.

[thecroweater]

once you have flooding or even channeling you no longer have reflux, that not just with marbles that's anything full stop