Equalizing a column or getting everything in the boiler upto temp.

[Dancing4dan]

How much of the advantage of doing it that way, is due to "stacking the column"
And/or how much is from entire boiler charge getting up to temp?

How do you answer "How much of the advantage...?"

Stacking the column includes having the boiler charge and column up to stable temperatures so that a "fuck ton" of reflux occurs!

Kinda like the chicken or the egg...no one cares!

What does shadylanes second sentence mean? I HAVE to be reading it wrong.
And a guy above says if he slowly brings the wash up to temp he gets better cuts???? Why?
I'm sorry I'm not understanding.

I don't know. And, I don't know.
If it works for him, thats great! If you tried it and it does not work for you, that's great.
Sometimes the big picture just is what it is. Ask my wife why when she steers the car left it goes left. She will tell you... "I don't care why!"
There are as many ways to run a still as there are people running them. And almost as many different stills! Why something happens on a pot still but does not on a reflux still, or on a Tuesday still run....I don't know.
I'm not sure it matters. The discussion above is great food for thought and gives us an opportunity to try doing things a little different next time, If we chose to.
Lets not chose heart attacks and grey hair over this!

[Hügelwilli]

I have a question on my continuous fuel still.

The top of my column is 170 and etoh and heads come out the top.
My boiler is 212 and my column drains down to the boiler. Let's say I run 20 gallons through. Where do the tails go?
Well, they have to come out the boiler.
Which means the temp drops a degree or so.
So now I'm at 211.
Does that lower temp mean a tiny bit of ethanol is making it out?

The tails are split in two parts:
One of them is the acids. Those fall down to the boiler.
The other part is the higher alcohols. Those accumulate somewhere in the middle of the column. This is why stills for neutral alcohol often have a "fusel side draw". I think, especially if your column has a small diameter and therefore not much volume, you should have this, if you want to distill a large wash continuously, because more and more of the higher alcohols will make it into your distillate. Or, because you only make fuel, you simply don't care, because those higher alcohols are flammable too.

The acids in the bottom of the still can rise the temperature a bit. I am not sure if it is measurable, because you empty the boiler continuously.
It depends on the number of plates of your still if there is a significant amount of ethanol at the bottom.

[NormandieStill]

What does shadylanes second sentence mean? I HAVE to be reading it wrong.
And a guy above says if he slowly brings the wash up to temp he gets better cuts???? Why?
I'm sorry I'm not understanding.

Imagine a worst case scenario: A thin tall boiler with an element halfway up. You will have boiling occur when the liquid above the element has heated to its boiling temp, but a large amount of the liquid below the element will still be lower temperature. And at the bottom it may well be cold. Given enough time (and not too much loss to the environment) the liquid will all mix and the whole charge will be at the same temperature.

The same thing will happen on a lesser scale in a "normal" boiler. How long it takes before the liquid directly above the element and the rest of the charge reach the same temp depends on the shape of the boiler and height and length of the element (ignore this for direct-fired boilers).

If only part of your charge is boiling, then only some of your heads are evaporating. Hence (as I understand it) Shadylane's question.

[Saltbush Bill]

magine a worst case scenario: A thin tall boiler with an element halfway up.

It often helps and should in this case...........I think.

[shadylane]

....If only part of your charge is boiling, then only some of your heads are evaporating. Hence (as I understand it) Shadylane's question.

Thank you.

[drmiller100]

Hügelwilli. Thank you!

[squigglefunk]

i think that by the time the vapors get all the way up the column, the entire charge in the boiler has become homogenized temperature-wise.

[RC Al]

Squiggle, not the case
Theres more than one account in the element height threads of being able to put a hand comfortably on the bottom of a boiler mid run, very much implies mixing not happening.
( Dont yell at me if you try this at home and burn yourself folks )

[CoogeeBoy]

Ok, some measurements are in order, I haven't done this math in a while so if something is wrong someone should correct me.

Assuming a 3" column with a 60" height that is 424 cubic inches, or 6.95 liters.

Lets assume that what's in the column is pure methanol, it probably isn't, its sort of best case.

Methanol is 1.202kg/m^3 at 65°c (just above its boiling point). 6.95 liters = .00695 m^3. .00695/m^3 x 1.202kg/m^3= .0084 kg = 8.4g.

So you have 8.4 g of vapor in your column.

At 20 c methanol is .7913 g/ml so in this hypothetical column, that makes 10.6 ml. A tablespoon is about 15 mils. So assuming you had no packing in the still, and you could purge everything that wasn't vapor you could potentially have 2/3 tablespoon of methanol vapor in your column.

Now lets back down the empty column assumption, and instead assume that column is packed with marbles (because they are the easiest to do the math on). The porosity of any group of spheres is 23%. So now you are down to about a 1/6th tablespoon of pure methanol vapor in your column.

Could make further assumptions about what is going on in the boiler but there is enough violence in there from the boil I would expect sufficient entrainment not to be able to use the volume, unless you had a very small relative amount of liquid in the boiler.

Lets not forget, the fores are mixed with a good percentage of ethanol, water, and "stuff", and most of that is more expansive than methanol.

So no... Can't fit that tablespoon of fores in your column. Not even close.

I knew that........ This one's way above my pay grade.

[TwoSheds]

Theres more than one account in the element height threads of being able to put a hand comfortably on the bottom of a boiler mid run, very much implies mixing not happening.
( Dont yell at me if you try this at home and burn yourself folks )

I found this to be exactly the case during my cleaning runs on my 3 gallon still. Since then I have bent the element so it goes very close to the bottom of the kettle and I _think_ I have it resolved.

[Ben]

The next time I do a run I'll shoot the side of my kettle in a few places with an IR GUN and see what the variations look like. SS isn't the best for this but it would be interesting. In the brewery I always run the recirc pump to verify temp homogenity, a pot can have a 15 degree differential at 160. The mash is worse.

[Ben]

The next time I do a run I'll paint a black strip on the side of my kettle and hit it in a few places with an IR GUN and see what the variations look like. SS isn't the best for this but it would be interesting. In the brewery I always run the recirc pump to verify temp homogenity, a keggle can have a 15 degree differential at 160.

[jward]

Theres more than one account in the element height threads of being able to put a hand comfortably on the bottom of a boiler mid run, very much implies mixing not happening.
( Dont yell at me if you try this at home and burn yourself folks )

I found this to be exactly the case during my cleaning runs on my 3 gallon still. Since then I have bent the element so it goes very close to the bottom of the kettle and I _think_ I have it resolved.

Interesting. I use a ripple shaped element. I was orienting it flat plane up so the total element height is lowest to require less wort to keep the element covered. I did notice that rotating it ripples up and down puts part of the elements very close to the bottom without touching, of course, part of the element being higher too. I'll have to measure the kettle bottom temperature to see if the flat horizontal position leaves some cooler wort on the bottom.

[TwoSheds]

Interesting. I use a ripple shaped element. I was orienting it flat plane up so the total element height is lowest to require less wort to keep the element covered. I did notice that rotating it ripples up and down puts part of the elements very close to the bottom without touching, of course, part of the element being higher too. I'll have to measure the kettle bottom temperature to see if the flat horizontal position leaves some cooler wort on the bottom.

Mine was in a 3 gallon milk can which I had a ferrule welded onto. The welder put the ferrule a little higher than I would have preferred, probably 2" or so from the bottom, in order to avoid a seam.

If you're down to a half inch or less I would suspect you're fine, but worth checking if you can reach the bottom of your kettle during a run.

[squigglefunk]

Squiggle, not the case
Theres more than one account in the element height threads of being able to put a hand comfortably on the bottom of a boiler mid run, very much implies mixing not happening.
( Dont yell at me if you try this at home and burn yourself folks )

ah I see, another issue with elements to consider eh? you're only boiling some of the liquid in the boiler, seems like this would really mess with cuts if parts of the mash haven't even begun to vaporize while the still is already running? smeared from the start in a way?

[Ben]

Give and take with the electric element thing I guess. Data is needed before condemnation though. Even a gas boiler can have quite a bit of temp deviation before the boil starts, especially if the boiler is stainless.

I don't think temp variation is completely avoidable. Maybe the better question is how much difference is it really making, and is the difference good or bad. A boiling solution has quite a bit of movement in it, regardless of the heat source. Water conducts well.

In the case of my pot specifically I could add a triclover plate with a camlock to my fill port and use a pump to constantly recirculate out of the bottom drain, that should homogenize the temps some, but what data would I collect? I am not good enough at this to make identical cuts at every step, it would have to be volumetric. That could also add theoretical plates which would skew the result. I would have to pack my column to get a plate count high enough to make that negligable.

[Dancing4dan]

Squiggle, not the case
Theres more than one account in the element height threads of being able to put a hand comfortably on the bottom of a boiler mid run, very much implies mixing not happening.

Interesting! I could not understand why some senior guys said they were running reflux for so long before starting to take product but this may be the reason.

The ambient temperature or altitude may possibly play a role in this. For example, + 30 Celcius vs - 20 Celcius! Mile high or sea level. This is likely more of an issue with a high mounted / placed electric element.

In either case it is another reason to run as much reflux as your coil can handle for a while before starting to take product. Insulate the pot and boil the pot as hard as you can manage with 100% reflux to give the entire pot time to reach a hard boil.

This would be a bit of a challenge with a pot still. However, the Liebig condenser on my pot still is able to knock down full power on full boil with the Liebig angle adjusted to point straight up. I did this during cleaning and testing runs. Kind of like 100% reflux.

If you are able to do point the condenser straight up on a pot still would that give more time to have the entire pot come to a boil prior to starting product take off? Assuming the condenser has the capacity to return all of the condensates to the pot during this exercise. Mine made a lot of gurgling noise but handled all of the condensate.

Would that give better separation of fores and heads?

[Saltbush Bill]

I could not understand why some senior guys said they were running reflux for so long before starting to take product but this may be the reason.

Shadys first post in this thread says "full reflux for a while"
I see a few people who seem to think an hour is needed.
I know of at least one distiller "Minime"who spent a LOT of time chasing the perfect Neutral and building packed columns who often stated that anymore than 15 mins was unnecessary.
Personally I've never bothered to run full Reflux on any still for more than about 10 min.
There is no reason to wait longer before starting to slowly bleed off foreshots, anything more is a waste of time in my opinion.
If electric is that problematic when it comes to heating a wash I'm sure glad I've always stuck to using LPG.

[shadylane]

Personally I've never bother to run full Reflux on any still for more than about 10 min.
There is no reason to wait longer before starting to slowly bleed off foreshots, anything more is a waste of time in my opinion.

+1
Instead of holding 100% reflux for an extended time, keep the column @ 99% reflux and slowly drip out the more volitile 1%
This will give the boiler charge time to get evenly up to temp, the column stabilized and the forshots disposed of.

[Saltbush Bill]

Couldnt agree more, I see no point in watching a still do nothing for an hour when you could be utilizing that time bleeding fores off,
Any still that cant make good booze without an hour to stabilize first needs rebuilding or throwing in the scrap bin IMO.

[LWTCS]

Personally I've never bother to run full Reflux on any still for more than about 10 min.
There is no reason to wait longer before starting to slowly bleed off foreshots, anything more is a waste of time in my opinion.

+1
Instead of holding 100% reflux for an extended time, keep the column @ 99% reflux and slowly drip out the more volitile 1%
This will give the boiler charge time to get evenly up to temp, the column stabilized and the forshots disposed of.

Yep.
To add further, enriching the column is important for holding proof. Not quite as critical with more plates (actual or theoretical).
As an aside, the longer reflux period only increases the likelihood of dragging up fusels.

Similarly, high reflux ratios while in operation also drag fusels further up into the column. Not nearly as bad with packing since the liquid mass (dwell time) in a hobby sized pack column is just not that big compared to the liquid mass and dwell time of an actual plated column. This is why some guys complain about tails being drug all up into their likker and they can't figger out why. Its cuz they have actual plates and need to take a chill pill on the heavy reflux.

Odin used try and throw shade on plated columns for this reason. But in reality it is guys trying to make the column behave outside of its comfort zone in a way. More to do with operator error really. But then Odin was constantly stumping for his methodology (and equipment) on seemingly a daily basis.
Yeah plated columns can run like the devil and do have a much wider operating range with respect to hydraulic behavior. It's why so many commercial distilleries use them. And the thing that allows them to have the wider operating range also is the thing that does a better job of trapping flavor ( both good and bad).

Run your plated column accordingly.

[Dancing4dan]

Cool. Good to know

[shadylane]

The fluid in the boiler is all the same temperature.

Grab a long temp probe and do some measuring.

Measure what?

The cooler layer of wash near the bottom of the boiler, after the boiler is already boiling on the surface and making vapor. Proper foreshot separation can't be done until all the wash is boiling hot and the column stacked. The cool layer of wash can lead to smearing.

On my electric boiler it takes around 15 - 20 minutes after the column is hot and alcohol is being produced, before the bottom layer in the pot is as hot as the rest of the boiler charge.

On a side note, an agitator really helps avoid this problem.

[drmiller100]

The fluid in the boiler is all the same temperature.

Grab a long temp probe and do some measuring.

Measure what?

The cooler layer of wash near the bottom of the boiler, after the boiler is already boiling on the surface and making vapor. Proper foreshot separation can't be done until all the wash is boiling hot and the column stacked. The cool layer of wash can lead to smearing.

On my electric boiler it takes around 15 - 20 minutes after the column is hot and alcohol is being produced, before the bottom layer in the pot is as hot as the rest of the boiler charge.

On a side note, an agitator really helps avoid this problem.

Where is the heating element in your boiler? What is the general shape of your boiler? Do you have baffles or insulators in your boiler?

[shadylane]

Where is the heating element in your boiler? What is the general shape of your boiler? Do you have baffles or insulators in your boiler?

Here's when I built the boiler.
viewtopic.php?t=57812

[drmiller100]

Where is the heating element in your boiler? What is the general shape of your boiler? Do you have baffles or insulators in your boiler?

Here's when I built the boiler.
viewtopic.php?t=57812

It looks like one element is about half way up and the other is about 1/5 up from the bottom? And you are using the bottom element?

And you are aware boiling causes violent vapor pockets to occur?

And you are saying you believe there is a layer under the bottom element that didn't mix and is significantly cooler.

And you believe the compounds in the boiler are not free to mix because of this temperature gradient?

Do I understand you correctly?

[shadylane]

It looks like one element is about half way up and the other is about 1/5 up from the bottom? And you are using the bottom element?

I'll call Bullshit on Ya.
You saw the pictures, do you honestly think "one element is about half way up and the other is about 1/5 up from the bottom"

Your persistence in misrepresenting facts, leads me to question everything else you say.
While I'm riled up and ranting, which I try to avoid.
Were's the pics and proof that you know what you're talking about.

[drmiller100]

It looks like one element is about half way up and the other is about 1/5 up from the bottom? And you are using the bottom element?

I'll call Bullshit on Ya.
You saw the pictures, do you honestly think "one element is about half way up and the other is about 1/5 up from the bottom"

Your persistence in misrepresenting facts, leads me to question everything else you say.
While I'm riled up and ranting, which I try to avoid.
Were's the pics and proof that you know what y
ou're talking about.

Well, I was looking at only the bottom part of your boiler not the whole thing assembled. ..

Im guessing you are agreeing the heating elements are really close to the bottom.

And your argument is that bottom inch of wash is not being heated like the rest of the wash and is somehow causing smearing. ..

I believe that a wash should be boiled for several, maybe many minutes to drive the nasty heads out of the wash.

Can we agree on that?

[shadylane]

And your argument is that bottom inch of wash is not being heated like the rest of the wash and is somehow causing smearing. ..

Even with a well designed electric boiler. It takes time for all the wash to get boiling hot.
Until that happens, it's not possible to stack the column with the most volatile vapors, because they haven't had a chance to boil off yet.

[shadylane]

During the time it takes to get the pot uniformly boiling.
I have the take off at a steady drip to draw off the nasties.

I believe the way to concentrate the heads is to run it in full reflux a while. Then pull everything off the top on one dump. Should be a table spoon or two.
repeat.
Repeat a third time. If it is still nasty you can go again.

Or. You can pull heads one drop at a time so the nasties get diluted with good etoh.

I disagree, because fiddling with the controls is unnecessary and counterproductive.
Leave the column in a steady state and wait.