Question for the "Math Smiths"

[LWTCS]

Don’t have enough mental ammunition to sipher my way out of a paper bag.

Please bare with me for a moment. Hope you math fellers are reasonably familiar with my design.

I would like to do an experimental extended 100% reflux period with my still (fully assembled). I will start with dry thumpers. I will let the dephlegmaer fill/charge all of the thumpers during this reflux cycle.
I would like to run the still in this reflux mode till the unit is fully cycling. In other words, till all overflow tubes are draining back to the vessels below and ultimately to the primary boiler. During this time when alcohol vapor is rising through the still and high abv liquid is draining downward, I have found my still yields its highest abv.

But my question is…At what point (with my still) will there be no added value supplied by a boiler with little to no remaining alcohol? Assuming all of my thumper vessels had enough available volume to capture and hold most nearly all usable alcohol within the given refluxing period.
And when the boiler is fully depleted of its alcohol, will the refluxing cycle then reverse it’s self and start adding water back to the alcohol isolated within the thumper vessels?
And finally, about how long would that take? Just hoping you fellers can get me closer to the mark so I don’t waste time or more specifically,,, so I am more productive with my findings.

20-25 liter charge @10% abv
40% input= 1792 watts during reflux cycle

Thanks for any insight.

[olddog]

I aint no maths theorist, so I can't give you any scientific numbers, but the principle of distilling is easy, it's just condensing vapor and getting the right bit of alcohol out of it.
Since changing my water supply to a lot larger container, I can now do a complete run without the need to restack. After taking heads and forshots, I let my still fully reflux for half an hour, I have a temp guage directly under the deplagmater which with the increased water supply I can now maintain a still head temperature of 79 degrees which is the temp that I take off the hearts, when all useable hearts have been taken, delivery from the Graham decreases to just a few drips, still at 90ABV, but not worth collecting. I then turn off the deflagmater and run the column in potstill mode to collect the tails, its surprising how little comes out, it will drop from 90ABV down to 20 ABV within 3-4 minutes and whats left in the boiler is mainly water.
I find that once you can maintain the correct temperature the still will behave automatic.
Sorry I can''t give you any numbers to theorise with.


OD

[LWTCS]

Thanks OD.

Recon what I want to do (dunno why) is extract ALL the alcohol out of the boiler and postion it into the thumpers before I collect one drop. Talked about this before.

Recon I want to know that it can be done. And about how long that would take so that I'm not wasting electricity and time refluxing for naught. Also do not want to create a point of diminishing returns during this reflux period.

Loneswinger putting together a calculator for column equalibrium times and recons he can git me in the ball park with the reflux time.

Sight glasses all round would be helpful aye Mike?

Recon he'll be along to articulate.

[olddog]

Sight glasses would be nice for you to see whats happening, but I think that being able to see and control the vapor temp is important with this type of column.


OD

[LWTCS]

I don't have any thermometers yet either.

Need to get moving on that I guess.

[olddog]

I think you would find it easier with one. Like it or not, what you have got is really a Flute column , with one huge bubble cap on each fixed plate, you could mount your dephlagmater directly over the top chamber, which would then be the ideal placement for the temp guage, as the top chamber is the business end where you take the ethanol from.


OD

[LWTCS]

Yep I'd like to get a port installed at the top and at the boiler

[loneswinger]

Ok man my programming skills suck, this thing took me so long to debug. Anyway, I wasn't 100% sure of your design, so I ran the program for 4 thumpers? The lowest one being 6 liters, the others being 433 ml. If it is different then just let me know. I can not easily change the number of thumpers (or plates as far as the program is concerned), but I can change them with a little effort.

The major assumptions with this program are: 1. The solutions on the plate mix instantaneously so the solution is always uniform. 2. The vapor coming from a plate below are completely condensed in the liquid on the plate. 3. Ethanol and Water volumes are additive (this made book keeping a lot easier but is not correct and the volumes while running the code could be off by as much as 5%). I could go on, but here are the results.

25 Liters of 10% at 1.8 kW in boiler

There could still be errors but this is what I have for now. These are the concentrations in solution on each thumper during full reflux as a function of time. Larry your predicted drop in ABV appears to be there for all the thumpers but is least significant for the top one. You can see when the bottom thumper is finally full by the upturn in boiler ABV (just after 5000 seconds) as the thumper starts dumping back into the boiler.

If anyone wants this program I will give it out freely. I wrote it in Matlab which kind of sucks as most people do not have it. The language is similar to C++ if someone wants to rewrite it for different software. It would be nice to know if it was behaving correctly.

-Loneswinger

[LWTCS]

Dude that is so generous of you to do that.

So based on your assumptions then I'll be at peak performance (for the higher abv) at round bout 3000 minutes into the cycle with the given input values.


Wonder if more goodly rumminess starts to carry over after the 8000 second mark?

How much did my tubing sizes affect the program as we did not discuss that.

BTW, 5% error is totally close enough for me. But as the Senior Vice President of Production for Garage Likker Inc. I'm afraid I'm gonna have to put you on probation.

Seriously though,,,,Thank you so much.

[Kentucky shinner]

I have a temp guage directly under the deplagmater which with the increased water supply I can now maintain a still head temperature of 79 degrees which is the temp that I take off the hearts, when all useable hearts have been taken, delivery from the Graham decreases to just a few drips, still at 90ABV, but not worth collecting. I then turn off the deflagmater and run the column in potstill mode to collect the tails, its surprising how little comes out, it will drop from 90ABV down to 20 ABV within 3-4 minutes and whats left in the boiler is mainly water.
I find that once you can maintain the correct temperature the still will behave automatic.
Sorry I can''t give you any numbers to theorise with.


OD

I experience the exact same thing. It amazes the hell out of me...

[LWTCS]

So,, while you have your tool belt on:

*Will the results for each thumper remain the same if there where no thumper above?
*How would larger thumpers affect the curve?
*How will a larger boiler charge affect the abv of the lower thumpers? I assume the lower thumpers would increase in abv? If this where true I would be curious to see if one could collect at,,,,,,,,,,,,break neck speed (after taking fores n heads) once the optimum amount of alcohol has been stacked into the thumpers.

[LWTCS]

I would be curious to see if one could collect at,,,,,,,,,,,,break neck speed (after taking fores n heads) once the optimum amount of alcohol has been stacked into the thumpers.

This BTW is the entire reason for this thread.

KS uses the expression "rain maker"

I want to be able to stand under my discharge and shower in 90+ @ 1.5 gpm . And as my flesh peels away I will,,,,,,smile,,, then grimmace

[loneswinger]

So based on your assumptions then I'll be at peak performance (for the higher abv) at round bout 3000 minutes into the cycle with the given input values.

Something like that. It is probably better to error on the side of too long of time than too short. The program only considers ethanol and water, not the other stuff in there.

Wonder if more goodly rumminess starts to carry over after the 8000 second mark?

No idea, but it isn't until about that long that the column finally goes into equilibrium. How that affects flavor? I don't know.

How much did my tubing sizes affect the program as we did not discuss that.

I did not include it. The program doesn't consider things like liquid entrainment and flooding. Your gonna have to go purchase software if you want that. I think as long as the vapor speed in the open section of tubing stays under about 50 cm/s, these things should not come into play.

Seriously though,,,,Thank you so much.

I wanted to write it anyway, you just gave me an excuse. Your welcome.

-Loneswinger

[loneswinger]

So,, while you have your tool belt on:

*Will the results for each thumper remain the same if there where no thumper above?
*How would larger thumpers affect the curve?
*How will a larger boiler charge affect the abv of the lower thumpers? I assume the lower thumpers would increase in abv? If this where true I would be curious to see if one could collect at,,,,,,,,,,,,break neck speed (after taking fores n heads) once the optimum amount of alcohol has been stacked into the thumpers.

I was also curious about the answer to your first one so I will check it out. Larger thumpers will probably just make it take longer to equalize. Higher boiler ABV should increase the alcohol in every thumper, especially the lower ones like you said. It would not be that hard to alter the program so that you could collect output. It would be interesting to see how the equilibrium is disrupted at different output speeds. I think I will try this as well.

-Loneswinger

[loneswinger]

Here is the answer to question one. Not much of a difference but some...

-Loneswinger

[LWTCS]

Don't know how to respond to a specific quote as I am on the hand held at present.

I was wondering if,,when the curve starts it's downward turn and the compounds with higher boiling points start to make their way through the still,,,would those compounds be a good thing? A really good esterfication point within a cycle or just a bunch of raggidy ass tails mucking up the works?

Of course I realize at present you have no way of knowing. I'm just posing questions for consideration

[loneswinger]

Seems to me that those compounds in small quantities would be a good thing, it is so hard to say without just trying it out though. It could be that even with the ABV decreasing, those compounds might be slowly working there way down so their concentration could actually be decreasing with increased equilibration time. Hard to say.

OK last mod to the program for the day is finished. I included an output. You can set the time that the output turns on and at what reflux ratio. Below is the same parameters as before but collection turns on at 1 hour and a reflux ratio of 2:1.

I will add the ability to include a bunch more plates, then the program will be complete.

-Loneswinger

[LWTCS]

Thats a cool little "Titty" spike just before the bottom falls out (first graph).

Wonder if a bigger boiler charge would prolong that spike?

Note to self:
Spiked titties are wonderful.

[loneswinger]

Thats a cool little "Titty" spike just before the bottom falls out (first graph).

Wonder if a bigger boiler charge would prolong that spike?

Note to self:
Spiked titties are wonderful.

I have played with the titty spike a little more and it won't go away. What will happen with a bigger charge is as soon as you turn on the output, the plates will adjust to a new, less efficient equilibrium. It will level out to the new equilibrium though with a bigger charge. Things that minimize the change in equilibrium is more plates or a higher RR. The program can handle 11 plates now.

-Loneswinger

[LWTCS]

Did a really good job of getting me close.

I'm thinking site glasses will be next on the mod list.I'll land those in.line with my liquid line over flow. if I'm making vodka, I'll adjust my dephleg and start. Collecting soon as the liquid level reaches.the mark.

At least now I have a reference for time.

Pretty handy tool

[loneswinger]

Just let me know if you want to run a different combination of input parameters. I have been tinkering with the program quite a bit to see what different combinations of inputs does.

I am trying to get someone to rewrite the code for use as a free web app. I will let everyone know if this actually happens.

-Loneswinger

[jake_leg]

I reckon acetate's yer man for getting the simulator up as a web app.

My programming sucks but I know a little bit about "translating" MATLAB code into R, which is freeware.