Marbles vs ss scrubbers for packing

[shadylane]

I'm at a point were a marbles vs scrubbies experiment is easily done.
I figure to use the same boiler, power and 100mm x 1000mm CM column with different packing.
The reflux condenser, it will be slowly adjusted to different abv outputs and the volume measured.
Then change the packing and do it again with the same abv still charge.
I'm open to any help I can get

[OtisT]

Don't know much about operating a CM, so will mainly spectate on the thread. good luck.

[Klein]

Well I'm interested in seeing how this turns out.

[bluefish_dist]

Run a short section maybe 24" and compare the max abv you can pull. That will show which has a lower hetp. I ran one wash through different plate setups and you can quickly see which provides the best separation by running a setup that can't reach azeo and just comparing how close they come.

I have wanted to do this for a while and also compare lava rock. Just have been too busy with production.

[shadylane]

I've got the boiler filled half full with 1 gallon of 95% ethanol and 7 gallons of water.
The element is 4500w plugged into the 240v outlet.
The CM column is 4" X 36" and filled with CC scrubbers.
Guess it's experimenting time

[shadylane]

Run a short section maybe 24" and compare the max abv you can pull. That will show which has a lower hetp. I ran one wash through different plate setups and you can quickly see which provides the best separation by running a setup that can't reach azeo and just comparing how close they come.

You have a good point I'll try a shorter column after I'm done with this.

[shadylane]

After getting a little experience, It looks like bluefish has a better point than I realized.
Based on what I have on hand, a tall column isn't the best tool, for comparing the HETP of different packings

[bluefish_dist]

You are doing the test I want to do. I thank you for taking the time to do it.
I wanted to run 24" packed with various packing materials from the same 10% wash at a maximum reflux. On my rig that is 3.5 turns out on the takeoff valve. Then compare the abv between setups. You do need a high accuracy hydrometer as the difference will only be a few proof.
Based on what I saw from running plates that will quickly show the difference in Hetp. I could not hit azeo from 3 ft of packed, so I thought 24" would maybe show more difference. If you need a 24" spool of 4" I have one you can borrow which has a plate in it to hold packing.

[shadylane]

Hell's fire
This simple experiment just got more difficult
Is 24" or 12" or less, a better length to test the packing a 4" column

[Yummyrum]

Shady , I'm also eager to see where this goes . The HD parent site and my intuition says scrubbers will be better but the Rad marbles and fan club swung it the other way .

As far as 12" 24" or 36" goes Hmmm good question . I can only go on instinct here again and say that the higher will be the better because it will even out variations in packing densities and channeling .

I agree with Bluefish about the high end of the Alc meter being more difficult to compare apples but the less reflux will bring that down as you know .
In my mind repeat-ability of the RR will be the hardest part to achieve . Also return the collected stuff back to the boiler and repeat so the boiler charge is the same .
My tuppence also would be to take off for a period of time say 1/2 hour before taking a sample so you know that the still has stabilized and is at the same operating point .
( base all these suggestions on some comparison tests I did on CCSC forum comparing Flute RC reflux diversion )

Good luck with the testing

[shadylane]

I'm not real happy with my experiment
The valve that controls water flow to the condenser is very touchy.
Therefor it was difficult to control the reflux with any repeatability
Long story short. I set the valve to were it normally is during a run and left it there.
The output with marbles averaged 59ml per minute and the SS delivered 66ml per minute.
The abv for both packing's was 95%
I've reconfigured the still and will try a shorter packed column for the next tests

[shadylane]

Here's the still reconfigured.
The tests will be done with 4 -1/2 inches of packing
The reason I picked this size, was that's what fits in my sight glass.
The defleg is bigger than the column, Hopefully it's eight 1/2" tubes will distribute the reflux evenly

[shadylane]

I changed the crappy reflux cooling water valve
The reflux was adjusted, so the still had 60ml per minute output.
After many runs, here's the average numbers
The abv of the marble packing was 85%
The abv of the SS scrubbies was 92%
I was really surprised that 4 -1/2" of packing worked this good
I was expecting much lower numbers than this

[bluefish_dist]

That confirms what I have observed. Marbles are not quite as good as scrubbies. Can you try lava rocks? Would be good to see how rocks compares as well.

[shadylane]

I'll have to wait until tomorrow, so I can buy some lava rocks.

[Klein]

How much power was used for each run?

[rgreen2002]

Interesting! Now I'm really curious about the lava rock.... so much talk about it over the years...

[shadylane]

How much power was used for each run?

A 4500w element screwed into the boiler. Plugged directly into a 240v receptacle

[shadylane]

Interesting! Now I'm really curious about the lava rock.... so much talk about it over the years...

I'm kinda curious about lava rock also.
When I get the bag of scoria, I'll hand pick the best pieces out.
Edited
I'll hand pick what I think are the best pieces

[Klein]

From my research it seems that marbles can handle much more power than scrubbers.
(I can’t confirm this because I have never use stainless steel scrubbers)

My 2” column with 14mm marbles can handle 2825 watts, anymore and it would flood. If we scale that to a 4” column then it should handle 11,300 watts. It’s hard for me to know for sure as I don’t know the marbles sizes you use, or the exact voltage at the receptacle. From my experience with the 2” your marbles were only getting 39.8% of the power it could handle (assuming a max of 11.3kw before flooding and 4.5kw of input). I suspect if they are not given enough power that the performance of the marbles is reduced. If this is the case then it would be interesting to compare them with both packing under there optimum conditions.

This has me thinking that I should do some testing with marbles comparing marble sizes to column sizes to power inputs while keeping a constant reflux ratio.

I have a new 4” column and marbles for packing and I have not run it yet, but will soon.

[shadylane]

This has me thinking that I should do some testing with marbles comparing marble sizes to column sizes to power inputs while keeping a constant reflux ratio.

Sounds like a great idea

[Yummyrum]

Good result shady

I'm kinda curious about lava rock also.
When I get the bag of scoria, I'll hand pick the best pieces out.
Edited
I'll hand pick what I think are the best pieces

There is a huge difference to be had . I tried large pieces initially around 3/4" - 1" in diameter . It was absolutely hopeless .
Thn I tried smaller pieces 1/4" - 1/2" in diameter and the difference was startling . Sorry no mumbers but I now use a 1m 4" packed with this scoria as my nuetral column . I will be interested to see you pull numbers on it as I'm quite happy to go to scrubbers if it works better .

[shadylane]

Here's the lava rock and the boiler is plugged in

[shadylane]

Tested the scoria under the same conditions and it was 90%
The scrubbies were 92% and the marbles 85%
I'm rerunning all the tests to be sure.
Tomorrow I'll buy a bottle of everclear and test my alcoholmeter
I suspect it's reading higher than it should.
But that wouldn't change the outcome of the comparision tests

[shadylane]

@ Klein
I'm sure your right about different packings, needing different power and reflux for optimum performance
But I'm lazy and didn't have the energy to explore all the possibility's

[Klein]

I made an excel sheet to enter my data. it will do some calculations for me once I start my runs (next week when I get home). once I can find say 2 more sizes of marbles (I already have 14mm) and I run them at different power levels and then in different size column.

The variables for each run that I will have these calculations based on are: the column size, the void percentage, power, collection time & volume (will calculate collection rate per minute and per hour), and alcohol content.
There is a fair amount of calculations on the spreadsheet, but it's well laid out and will be easy to compare each run. I plan on keeping a 1:1 reflux ratio with my ccvm

I can start another thread that way I'm not high jacking your thread.

[bluefish_dist]

Great results. Have you thought about running one plate and see how it compares?

[Yummyrum]

Interesting results Shady
What was the average size of the scoria ? Its hard to tell but looks bigger than 1/2" .
I guess klien has a good point about power handling or should that be reflux return handling ability.
There must be a trade off between surface area available for phase change and space for reflux liquid to flow .
Smaller size scoria gives a higher abv than larger sizes but if the smaller sizes don't allow enough space then it becomes a flood issue . Lots to explore .

Enjoying your experiments Shady

[rgreen2002]

NIce work ya got going on shady. The scoria info is very interesting to me as well. Like Yummy was saying, I wonder if there is an "optimum" size for the scoria or could the variability in size(to a degree at least) increase surface area and allow liquid flow withot flooding....

[shadylane]

Great results. Have you thought about running one plate and see how it compares?

Take your pick