Glass Marbles for Reflux Column Structured Packing

[rad14701]

I'm starting this topic to open a discussion about using glass marbles for structured packing in reflux columns... I have always considered marbles to be underestimated as far as their effectiveness as structured packing and would like to see whether anyone else has used them, whether successfully or unsuccessfully...

Checking the parent site one might surmise that marbles wouldn't be worthwhile from a purity standpoint... I have always disagreed but never did any testing to prove out my stance... Using the HETP's Calculator with various settings, and comparing between marbles and SS scrubbers, performance would seem dismal at first glance... However, I feel that theoretical and practical results differ greatly for a multitude of reasons... For example, setting the calculator to some baseline numbers of Column Diameter = 0.1, Packing Height = 1m, Reflux Ratio = 1, and Power Input = 1000W, SS scrubbers supposedly yield 0.085m HETP, 13.8 plates, and 95% ABV while marbles yield 0.256m HETP, 5.9 plates, and 91.9% ABV... Based on those numbers one might assume that in practical application marbles would be less than satisfactory for neutral spirits... In reality, this is not the case - at least in my own personal experience...

I recently began glass marbles in my small scale 1.25"/32mm LM reflux column with greater success than I had expected... What surprised me the most was the fact that I attained my highest purity spirits by using them... I was also surprised by how stable the run went and how the ABV hung right at 96.5% all the way to the tails at a seemingly rapid take off rate for such a small diameter column... 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...

The packed column section measures 30" and is completely filled with marbles with the exception of the top 1" and bottom 2" which have SS scrubber to hold the marbles in place during assembly and dis-assembly... I am using a concentric reflux condenser on top of my dual reducer LM head which has recently been fitted with an external reflux return tube, located on the back side and not visible in the picture below...

My last run of 3 gallons of 40% low wines produced 2.5 liters of ~95%+ neutral spirits, making overly conservative cuts from the 3.75 liters collected in total... While there were more acceptable spirits which could have been blended, I chose not to be greedy and tossed all but foreshots into the feints jug...

Let the discussion begin...

Concentric_LM_30inch_marbles.jpg

1oz_per_minute_using_marbles.jpg

96_5_ABV_using _marbles.jpg

[bearriver]

Thanks for the tip. Testing ways to increase HETP without modifying a larger column is on my "To-do list". Marbles being affordable, rank high priority on that list.

I have so far found marbles online ranging from 12mm to 50mm in diameter. Planning on trying the smallest marbles available.

EDIT: How large are the marbles in your column?

[DAD300]

I have minor experience with a ten foot tall x 8" Charles 803 with 3/4" marbles.

I've grown to have a lot of faith in the calculators.

The diameter of the marbles would have a great effect on the void in the column. How rough or smooth the surface would also.

The marbles allow for great penetration of the reflux, due to the greater void. Thermally they are a nightmare.

In your theoretical example of a 3.9" x 39" column...I think all of your ethanol would have been in the column and as stacked as it could ever be. Or, it would have been hard to hold any reflux from going back to the boiler.

How long did this run take?

[Jacksonbrown]

Looks safe

[rad14701]

@bearriver

I checked online but ended up buying bags full of 1/2" marbles at The Dollar Tree... Just remember, the marbles add a lot of weight to the column...


@DAD300

I'm actually able to push more heat into the boiler due to less chance of total flooding I had to avoid with SS scrubbers... I'd like to find even smaller marbles if they are available... Those 3/4" marbles you used sound way too big... Mine are 1/2" which is fine for larger columns, but they are almost too big for my small 1.25" column... That's why I was so surprised by how well they have been working...

My runs actually take less time with marbles because I can increase my take off rate... With SS scrubbers some of my runs were a bit finicky...

[Andy Capp]

I tend to agree rad. Marbles are crucified by members that don't understand their usefulness. My experiments with marbles found they worked great when used in a short column to single distill a ujssm through a boka. Uncle jesse used a still that operated in a similar fashion and that was my goal.
I haven't tried them with a neutral wash but i"m not surprised with your results.

[rad14701]

I tend to agree rad. Marbles are crucified by members that don't understand their usefulness. My experiments with marbles found they worked great when used in a short column to single distill a ujssm through a boka. Uncle jesse used a still that operated in a similar fashion and that was my goal.
I haven't tried them with a neutral wash but i"m not surprised with your results.

I mentioned in another topic about how I have used marbles for several years in my short stripping column... I've used as few as a dozen with no extension up to a jar full in a 6" stripper column...

[FullySilenced]

Rad what about something like these?

http://www.alibaba.com/product-detail/T ... 25284.html" onclick="window.open(this.href);return false;" rel="nofollow

4mm to 7 mm in diameter

http://www.alibaba.com/product-detail/C ... 15202.html" onclick="window.open(this.href);return false;" rel="nofollow

[rad14701]

FullySilenced, those would be nice but I'd imagine they would be substantially pricier than glass marbles... They would be just the ticket for a SS column, however...

[Hound Dog]

I bet it would be costly to pack a column with copper balls. Seems like they would need care or corrode up.

I would have thought the smooth surface of the glass marbles was undesirable. This is why I when with lava rocks. I like the thought of a consistent sizing like you would get with the marbles. I will need to experiment soon. I would think that a little smaller than 1/2" would perform well for 3" with low wines charge.

[googe]

I've always read there no good to so never tried them, good to see yet another myth dispelled with different running procedures rad. How does the taste compare to your normal runs?. I too would have tonight the smoothness would not be good, depends how clean it is, some high % can taste bad and some low % can taste clean. They would be awesome I reckon fully!. Imagine how much cross scrubbing would be happening on all the little surfaces!. The very reason I built my latest small cm was to have a compact still capable of producing high % at good speed, I'll be trying lava, and now marbles, and maybe some of them balls!. Thanks for sharing rad.

[bearriver]

I would have thought the smooth surface of the glass marbles was undesirable.

I too would have tonight the smoothness would not be good

Perhaps chemically etch the glass?... : http://en.wikipedia.org/wiki/Glass_etching" onclick="window.open(this.href);return false;" rel="nofollow

[Hound Dog]

Hmmmm... there's a good thought too Bear. Could try both etched and smooth to compare. I don't know how readily available the chemicals are but it would be pretty easy to rough them up in a rock tumbler/polisher. I can't wait to get my remodel done in my house and get back to experimenting a bit!

[Odin]

I had lots of succes with small basalt stones. Closer in shape and surface area to marbles than to scrubbers. I think marbles have been "dismissed' earlier because of the emphasize on surface area as the deciding criteria in reaching low HETP. But marbles could work as this: less open space, so higher vapour speeds & reflux having less space to drip down through. Gasses rising up through liquids. Now that would create lots of interaction. As in a flute with a higher liquid level: cleaner product. Stability could be a result of total mass in the column (packing & liquids).

Odin.

[ga flatwoods]

Instead of round marbles what about using the flat ones like used for fish tanks or clear vase displays for flowers. They come multicolored and are sold at most stores in the craft section. Seems they have more surface area and would fit more surface in a given length of pipe than round marbles would.
Ga Flatwoods

[Bushman]

With a 4" column and copper scrubber my column with the dephlag already weighs enough my biggest concern as mentioned earlier is weight for lifting onto the boiler.

[rad14701]

Instead of round marbles what about using the flat ones like used for fish tanks or clear vase displays for flowers. They come multicolored and are sold at most stores in the craft section. Seems they have more surface area and would fit more surface in a given length of pipe than round marbles would.
Ga Flatwoods

I almost bought some of those flat marbles, ga flatwoods, and still may give them a try... It costs less for those at The Dollar Tree than buying two packs of scrubbers, costing $1USD per bag of ~50...

I think in my situation the issue at hand has been vapor speed within the structured packing density... Rising vapor was moving so fast that at a decent take off rate and reflux ratio the reflux couldn't adequately flow back down through the packing and was retained in the reflux head... With marbles I can apply more power, have more reflux, and still attain higher take off rates... Combine that with the fact that the purity is higher and the resulting spirits taste cleaner, even the jars tossed in the feints jug, at this point I'm a firm believer in using marbles... Not to mention that they are easier to install, remove, and clean...

@Bushman

Yes, weight is the main concern with marbles... With a tall, large diameter column, unless you have a way to fill and empty the marbles in-place, their use may be impractical... I probably wouldn't even want to fill a 2" x 36" packed column section if it was to be mounted on an original stock pot lid due to flexing the thin SS...

[still_stirrin]

So, how do you hold the marbles in your column? I'm curious.

[Bushman]

So, how do you hold the marbles in your column? I'm curious.

[T-Pee]

Scrubbies or coarse SS screen should work.

tp

[Hound Dog]

So, how do you hold the marbles in your column? I'm curious.

Bushman's way would be best. I have something similar having drilled and soldered some copper rods across the bottom of mine to hold in rocks. I would think the weight of the marbles would push scrubbers right back out.

[rad14701]

In my small column small amounts of SS scrubber works to hold the marbles in place, but for larger columns the methods described and shown here would work better...

[The KYChemist]

Question: What about the lack of copper, for removing sulfites, in a column comprised of SS and marble packing? I have read it is good to have copper in the vapor path for doing so. That is why I went with copper mesh, instead of SS scrubbies.

[rad14701]

Question: What about the lack of copper, for removing sulfites, in a column comprised of SS and marble packing? I have read it is good to have copper in the vapor path for doing so. That is why I went with copper mesh, instead of SS scrubbies.

My column is copper but if it was SS I would have copper scrubber at both the top and bottom for sulfur compound removal... One scrubber at the top and bottom should suffice...

[ga flatwoods]

Rad if you had a larger column I would be willing to bet that the flat marbles would perform better than the round one as there is more surface area on each and the density per linear foot would be heavier than with the round with less void space.
Ga Flatwoods.

[rad14701]

Rad if you had a larger column I would be willing to bet that the flat marbles would perform better than the round one as there is more surface area on each and the density per linear foot would be heavier than with the round with less void space.
Ga Flatwoods.

I almost stopped and picked some up today... Not sure how much improvement I can get beyond 1.5 LPH @ 96.5% from a 1.25" diameter column... Would be interesting to find out though...

I want to try lava rock, as well, for comparison purposes...

[The KYChemist]

Rad, is that "1.5LPM@96.5%" your takeoff rate? Or is that the coolant flow. Or, is that supposed to be 1.5LPH, I referring to take off rate?

[wv_cooker]

Damn it Rad lets just take distilling back my god how many years LoL. I am just finishing a 3" x 36" cm column that was going to get Lava Rock in it. I will head off and gets some glass let's just see what we can do with one of the oldest packings there is lol.

Have you ever boiled marbles to crack the surface, we used to do it as kids for different projects and I assume that would be as good as chemical etching without having to use chemicals. Since surface area for the reaction of liquid with vapor is important I will get the flat ones GA has talked about and some round ones as well. Hmmmm maybe even a mixture of both would be good so lets try three ways. Going out to start a UJ and a BW will report back in about a week.

I can't believe the stuff we try sometimes LOL!

[ga flatwoods]

KISS beats rocket science in many ways. That is keep it simple stupid for those that do not know.
Sounds like a sweet rig there WV. Pics? Who taught you how to build something like that?
Ga Flatwoods

[rad14701]

Rad, is that "1.5LPM@96.5%" your takeoff rate? Or is that the coolant flow. Or, is that supposed to be 1.5LPH, I referring to take off rate?

Take off rate was 1.5 LPH(our)... Coolant rate was 1.5 LPM(inute)...

Previous post corrected...