Shinners Flute build.

[squidd]

KS,

Okay, so the vigorous boiling activity is highest at the top plate, and diminishes incrementally on the plates below.
But, the vapour temperature is highest at the bottom plate, since it's closest to the boiler.

That seems to be a contradiction, except that we also need LIQUID for boiling activity.

The top plate receives the largest quantity of liquid, being closest to the deplag, hence the activity even though it is the farthest away from the boiler.

We need to get MORE liquid to the lower plates.

That means LOWERING the liquid level on the upper plates, by lowering the top of the downcomers.

If you get it just right for the top plate, then plate #2 should boil just as vigorously as plate #1.
And so on.

squidd

[Mr.Spooky]

interesting

[rednose]

That would be great Joe.. I really want to know what happens to the bottom plate with a bubble plates..
Thanks, Look forward to seeing the results.
KS

Now there is no way back, my friend said it's ok to make the sigh glass today and I already disarmed the complete rig.

[loneswinger]

Ok, I think I figured it out, or am I least on the right track with a reasonable theory.

I assumed that you are putting 4000 Watts into the column (if less it could be worse), and that your % clear area on the plates was 3.5% (if greater due to leaks or unfilled traps it could be worse). For the upper plates, i.e. 90% ethanol, the pressure drop due to gas vapor flow through the perforated plates is about 230 Pa. This is enough to support a layer of 90% ethanol that is about 3 cm or about 1 inch thick. More than enough to fill to the inlet of the downcomer and more, plenty of pressure.

However, the vapor and liquid near the bottom plate has a lot less alcohol and a lot more water. So for the simplicity of calculation, I assumed that this was pure water. The pressure drop for water vapor flow is only 63 Pa for the same power (4000 Watts). This is only enough pressure to support a layer of water that is 0.6 cm thick or about 0.2 inches. Now that would still be ok, would still bubble, just would not fill to the down comer, all would be weeping through the plate.

I ignored bubble forming pressures in the above calculations so they are really only ballpark but they give you an idea. You are probably running with a configuration (power and plate) which works for high purity ethanol but not for low ethanol purity. Now I don't know for sure, but in reality you might be running less power into the column than 4kW. Also because of vapor leaks around the outside of the plates and up through the unfilled down comer, the % clear area could be higher which will make the pressure drops even lower.

In short, my newest prediction: The whole thing is too underpowered to run the bottom plates when there isn't much ethanol in the boiler. Maybe try running at whatever power the dephlag can handle. Then for output, just increase the boiler power but keep the water flow to the dephlag the same.

In the future (future plate builders) you might want to make the lower plates have a lower % clear area, i.e. drill less holes (or just smaller ones).

BTW, 4000 Watts at full reflux and the dephlag should be dropping 300 mL/minute of reflux, are you seeing this much? That is 20 L/hr which is a lot. I wonder if the dephlag is underpowered for this 4" beast.

-Loneswinger

[LWTCS]

Not using 4000 on full reflux.

I use bout 1400,,,plus or minus

[loneswinger]

1400 Watts won't be enough to support the liquid on the plates in a 4" column. Even the top plate could only support about 2 mm on pressure alone, beyond that it would start to weep. It would just be a manner of can the reflux getting onto the plate outrun the weeping through the plate as to whether or not it will fill to the down-comers.

I power my 2" column with 1200-1400 Watts. On an even scale you'd want 4 times the power with a 4" since you got 4 times the area.

That is, as was the previous post, to the best of my knowledge of course. I hate when other people post 'matter of fact' like, so I don't want to come across that way. This is my opinion based on calculations I did using an online calculator with unknown accuracy. It is entirely possible that it is complete BS, but the numbers sound ok so I trust them for now.

-Loneswinger

[rednose]

So my still has eyes now.

Have to install all and maybe on monday run it.

There will be 4 sight glasses but we didn't have more time.

[LWTCS]

Pretty sure I miss spoke after reading your post loneswinger. My still (and dephlag) should not be used as an example as my still head is a series thumpers contained within the 4". There fore my still behavior is much too different.

Clearly I have interjected at the wrong point in the conversation.

Still looks good Joe.

[olddog]

Okay, so the vigorous boiling activity is highest at the top plate, and diminishes incrementally on the plates below.But, the vapour temperature is highest at the bottom plate, since it's closest to the boiler.That seems to be a contradiction, except that we also need LIQUID for boiling activity.The top plate receives the largest quantity of liquid, being closest to the deplag, hence the activity even though it is the farthest away from the boiler.We need to get MORE liquid to the lower plates.That means LOWERING the liquid level on the upper plates, by lowering the top of the downcomers.

The reason for the activity on the top plate is because of the stacking which occurs with a refluxing column, the element with the lowest boiling point at the top of the column, and the element with the highest boiling point at the bottom, eg: water.
This allows you to take off the alcohol content of the wash, and return the water content back to the boiler.
It would not matter if you had two plates or ten plates, the principle still applies. The top plate will be the lowest boiling point, and the bottom plate will be the highest.


OD

[olddog]

I love your nice big windows Joe, you should get a good view.


OD

[loneswinger]

Pretty sure I miss spoke after reading your post loneswinger. My still (and dephlag) should not be used as an example as my still head is a series thumpers contained within the 4". There fore my still behavior is much too different.

Clearly I have interjected at the wrong point in the conversation.

I didn't actually know what kind of still you were running. I am still a forum newbie after all, thanks for the info. Is there a link to your still design? Sounds like you could run at whatever power you choose as long as the dephlag could handle it?

-Loneswinger

[Kentucky shinner]

So my still has eyes now.

Have to install all and maybe on monday run it.

There will be 4 sight glasses but we didn't have more time.

twins with eyes.jpg

she looks good.. The guy did a hell of a job on your sight glasses. I look forward to seing the results..
Great work..

[squidd]

Okay, so the vigorous boiling activity is highest at the top plate, and diminishes incrementally on the plates below.But, the vapour temperature is highest at the bottom plate, since it's closest to the boiler.That seems to be a contradiction, except that we also need LIQUID for boiling activity.The top plate receives the largest quantity of liquid, being closest to the deplag, hence the activity even though it is the farthest away from the boiler.We need to get MORE liquid to the lower plates.That means LOWERING the liquid level on the upper plates, by lowering the top of the downcomers.

The reason for the activity on the top plate is because of the stacking which occurs with a refluxing column, the element with the lowest boiling point at the top of the column, and the element with the highest boiling point at the bottom, eg: water.
This allows you to take off the alcohol content of the wash, and return the water content back to the boiler.
It would not matter if you had two plates or ten plates, the principle still applies. The top plate will be the lowest boiling point, and the bottom plate will be the highest.

OD

Hi OD,

Thanks for the clarification.

But here's what I still don't get.
KS stated that there was very little liquid (water) flowing onto the last plate. That means that all the alcohol vapor is contained between plate #3 and the dephlag.

So what would happen if we were to add (say,6 more for a total of 10) plates below #4 ?
Would they contribute anything ?

Or would more alcohol vapor from the boiler occupy the new spaces ?
Or would the column dynamics be totally different?

Thanks,
squidd

[olddog]

I have 5 plates in my Flute, 4 plates bubble the bottom one dosn't. KS has four plates in his Flute 3 plates bubble the bottom one dosn't.
I would bet my boots that if I had 6 plates, the top 5 would bubble. Joe's bubble plates may act differently as the will hold liquid and not collapse as a perforated plate can, but I chose to use perforated plates because I could build them with basic tools.


OD

[loneswinger]

KS stated that there was very little liquid (water) flowing onto the last plate. That means that all the alcohol vapor is contained between plate #3 and the dephlag.

So what would happen if we were to add (say,6 more for a total of 10) plates below #4 ?
Would they contribute anything ?

Or would more alcohol vapor from the boiler occupy the new spaces ?
Or would the column dynamics be totally different?

Thanks,
squidd

Just because there isn't much liquid on the plate, doesn't mean there isn't liquid getting to the plate. I think that there wasn't much flowing from the cup on the bottom plate (from the down comer above) because the plate above is weeping, so not as much is flowing into the down-comer. At full equilibrium and full reflux, there is as much vapor going up as liquid reflux going down at any section of the column. Regardless of down-comer height, number of plates, efficiency anything.

More plates should give you more purity at the top of the column. Other dynamics should change very little.

-Loneswinger

[loneswinger]

OD, I never got back a response from KS on this question.

Any idea how much power you are running your rig with?

-Loneswinger

[LWTCS]

Sounds like you could run at whatever power you choose as long as the dephlag could handle it?

Recon I just assumed that the other folks in the 4inch club were refluxing slowly as I do.

My dephlag can't knock down 100% at full power (4480 watts). But it does not need to as my still liberates and isolates higher proof at each level.

Sorry, not really related exactly to this thread.

http://homedistiller.org/forum/viewtopi ... 0#p6831483

[olddog]

OD, I never got back a response from KS on this question.Any idea how much power you are running your rig with?

I use a 3 ring propane Banjo type burner, I usually have the outer two burners to run the rig

OD

[loneswinger]

I keep mentioning weeping as if it is some bad thing. It is not, I don't want to lead you guys into thinking that it is or that you need to make some design mods to prevent it. It should not really affect efficiency until it gets so severe that the plate can no longer hold enough liquid to get good liquid/vapor mixing. It is much worse, efficiency wise to run the column at the other extreme where it is near flooding.

As long as you are satisfied with the alc% in your output that is all that really matters. From the sound of it you all want it a little detuned anyway to try to get some flavor through. (Sounds a little anti-american/pro-canadian whiskey like to me, but I guess I can let that go )

I use a 3 ring propane Banjo type burner, I usually have the outer two burners to run the rig

OD

Ok, thanks I will do a search and try to figure out how much juice that is.

And thanks LWTCS, I will take a look at the link.

Cheers,

-Loneswinger

[rednose]

I love your nice big windows Joe, you should get a good view.


OD

Thanks OD, I'm not very sure that I will keep them.

It's cause of the fire security company.

If something ever happens they could say: Haha, those glasses are not made for it and that caused the problem, f@ck ya.

For the actual discussion it will help to see what really is going on in the first plate.

Oh well I always can cut them and solder a commercial sight glass.

[squidd]

KS stated that there was very little liquid (water) flowing onto the last plate. That means that all the alcohol vapor is contained between plate #3 and the dephlag.

So what would happen if we were to add (say,6 more for a total of 10) plates below #4 ?
Would they contribute anything ?

Or would more alcohol vapor from the boiler occupy the new spaces ?
Or would the column dynamics be totally different?

Thanks,
squidd

......I think that there wasn't much flowing from the cup on the bottom plate (from the down comer above) because the plate above is weeping, so not as much is flowing into the down-comer.....
-Loneswinger

Okay, so this "weeping" would be in the form of liquid droplets ? Since there is no activity above plate #4, would they be visible ? Light drizzle ?

To prevent weeping I surmize that the size/quantity of perforations would have to be reduced. This could be simulated by putting some copper screen on plate #3 to test the hypothesis ?

Still trying to figure it out.

squidd

[Kentucky shinner]

From the sound of it you all want it a little detuned anyway to try to get some flavor through. (Sounds a little anti-american/pro-canadian whiskey like to me, but I guess I can let that go )

-Loneswinger

No need to detune.. all you have to do is turn up the burner some and you will get more flavor.. Actaully I think mine is perfect. :

[loneswinger]

No need to detune.. all you have to do is turn up the burner some and you will get more flavor.. Actaully I think mine is perfect. :

I meant detune as in not getting optimal efficiency out of each plate. I know you like your stuff, I am sure I would like it too.

If you want you can send me a couple gallons and I will send back a note telling you whether or not I like it.

-Loneswinger

[
Okay, so this "weeping" would be in the form of liquid droplets ? Since there is no activity above plate #4, would they be visible ? Light drizzle ?

To prevent weeping I surmize that the size/quantity of perforations would have to be reduced. This could be simulated by putting some copper screen on plate #3 to test the hypothesis ?

Still trying to figure it out.

squidd

Take a perforated plate put some water on it and watch it fall out the holes, that is what it looks like (except not so much liquid). You would have to look at the bottom side of the plate to see it, but it should be visible if it is happening. Your surmization is correct, to prevent weeping you need to either reduce the size/quantity of perforations, or up the boiler power. I don't really think that copper screen would do much to change the clear area. You would have to do something more drastic like plug half the holes with solder, probably on both plates 3 and 4 (you are counting down correct? top plate equals plate 1?)

If you know the boiler power, you (or I if you want) can calculate the clear area (i.e. size and number of holes) that are needed to run a given plate with a given down-comer height, assuming a certain purity on the plate. Since purity will change throughout the run, you can't really optimize it for any arbitrary still charge. I have heard its best to design at the lower limit of pressure drop, that is its better to have too many holes than not enough.

I hope this clarifies,

-Loneswinger

[squidd]

Thanks Loneswinger.

squidd

[JethroBodine]

So, the gist of what we're thinking now is that the upcomming vapor doesn't push hard enough to support the water in the lowest plate? Did all 4/5 plates bubble durring the water cleanout run? Wouldn't that be more like the condition that a run makes toward the end? Lowering etho level, rising temp, more water vapor rising?

rednose - I'll say it again... WOOOOHOOOOO!!!!

[olddog]

Did all 4/5 plates bubble durring the water cleanout run? Wouldn't that be more like the condition that a run makes toward the end? Lowering etho level, rising temp, more water vapor rising?

It's the reverse, this is why at the end of the run only the top plate is left bubbling.


OD

[Mr.Spooky]

this thread is one of the reasons that i LOVE HD. even though those who have the plated columns are extremely satisfied with them, there are so many more people that are interested in the dynamics of whats going on.
this is evolution in progress. this is how standards get set,,,, and i for one, feel privalaged to be a part of it.
to everyone,,,,,, keep up the good work!
Mr.Spooky

[LWTCS]

U sippin aincha Spook?

[Mr.Spooky]

[Mr.Spooky]

but i still ment what i said.