4" takeoff speed

[fiery creations]

I know the answer is "it depends" and I'm not looking for an exact number to run mine at, but rather those few with 4 inchers ball park take off rates in pot mode.

I went down the rabbit hole and see it may be more due to boiler charge, and that spirit runs all tend to take more or less the same time regardless of size. Yummy also pointed out something about two stills of half the size of a single bigger one running at the same time would have to collect twice as much to finish in the same time.

But doing the math on mine seemed to put me way above what I should have been at and it all smeared to hell. I really don't want to have to rerun a third time.,,, The calc has a 6 hour spirit run putting me at 6.5LPH if I stop collecting at 55%.

That is way too high right? 7LPH smeared to hell. What do you guys find to be the sweet spot?

[shadylane]

I know the answer is "it depends" and I'm not looking for an exact number to run mine at, but rather those few with 4 inchers ball park take off rates in pot mode.

At first I thought you were talking about a 4" packed or plated column.
A pot still is going to smear like hell at any speed and the riser dia has little or nothing to do with the takeoff speed.
Takeoff speed depends, are you distilling rum, whiskey or moonshine?
On a spirit run slower is better. For whiskey in a my 18ish gallon pot the takeoff is around 4 ltrs/hour.

[fiery creations]

I know the answer is "it depends" and I'm not looking for an exact number to run mine at, but rather those few with 4 inchers ball park take off rates in pot mode.

At first I thought you were talking about a 4" packed or plated column.
A pot still is going to smear like hell at any speed and the riser dia has little or nothing to do with the takeoff speed.
Takeoff speed depends, are you distilling rum, whiskey or moonshine?
On a spirit run slower is better. For whiskey in a my 18ish gallon pot the takeoff is around 4 ltrs/hour.

No, this is only my second spirit run with the plates out. The first one I kept it at 2.5-3LPH, but man... It took several days at that speed. After reading a bunch it seemed to be sensible that those number for a 15 gal 2" should be much higher on my 4 inch 26 gal, but it didn't turn out well.

22 gallon charge of 35% UJSSM low wines.

So 4LPH on the calc still puts me at over 10 hours just to hit 53%.

[SW_Shiner]

If its just a simple pot still, the take off diameter will have no real measurable effect on take off speed. Thats dictated by the ABV of whats in the boiler, but more importantly, power input. For example, i can run with 3 inch take off at 3000w or 2 inch take off at 3000w and they put out the same amount at the same speed and abv.

[fiery creations]

If its just a simple pot still, the take off diameter will have no real measurable effect on take off speed. Thats dictated by the ABV of whats in the boiler, but more importantly, power input. For example, i can run with 3 inch take off at 3000w or 2 inch take off at 3000w and they put out the same amount at the same speed and abv.

So column diameter only effects take off speed in a plated or packed column? Then the only advantage I have using this setup over my 2" 15 gallon is....It takes twice as long?

This really confuses me with all the old threads I poured through that said a spirit run should take about the same amount of time regardless of the set up. Why does it take me 10+ hours on this one and only a few on my other if this is the case?

[SW_Shiner]

So column diameter only effects take off speed in a plated or packed column? Then the only advantage I have using this setup over my 2" 15 gallon is....It takes twice as long?

Correct. Mostly, power input is what effects the speed. Take off speeds for reflux stills are generally set for a certain abv. My 3" will do 95% at 3lph, but i can just as easily take off at 80% at 4lph+ This is why a lot of people have a large boiler used for stripping, and a smaller boiler, or the ability to run less, for a spirit run. A large boiler can usually take higher power input before any issues may arise. For example, i wouldn't try to strip at 12000w through a 1/2in liebig. Thats why you'll often see pot still take off described as 'a small stream' rather than a number. It will be different for every still and every wash. Your power input will dictate your take off speed, boiler size will dictate how long the run is.

[fiery creations]

Okay... A quick search and wow. 15 years of reading threads and seeing diameter=speed and not once did I ever catch that the rule does not apply to pot stills. No wonder it's taking so long.

[Saltbush Bill]

You learn what take off speed suits your pot still by using your senses of taste and smell.........not by using someone else's numbers.
You need to be tasting/smelling right through the run, fores, heads, hearts, tails. If It's smearing to much your running to fast.

[fiery creations]

So column diameter only effects take off speed in a plated or packed column? Then the only advantage I have using this setup over my 2" 15 gallon is....It takes twice as long?

Correct. Mostly, power input is what effects the speed. Take off speeds for reflux stills are generally set for a certain abv. My 3" will do 95% at 3lph, but i can just as easily take off at 80% at 4lph+ This is why a lot of people have a large boiler used for stripping, and a smaller boiler, or the ability to run less, for a spirit run. A large boiler can usually take higher power input before any issues may arise. For example, i wouldn't try to strip at 12000w through a 1/2in liebig. Thats why you'll often see pot still take off described as 'a small stream' rather than a number. It will be different for every still and every wash. Your power input will dictate your take off speed, boiler size will dictate how long the run is.

Thanks, now it makes sense. I thought the pencil lead thing was obviously wrong for larger set ups, but now it's coming together.

You learn what take off speed suits your pot still by using your senses of taste and smell.........not by using someone else's numbers.
You need to be tasting/smelling right through the run, fores, heads, hearts, tails. If It's smearing to much your running to fast.

I'm aware of that, hence the first line of my post. That is why I said ball park numbers... So I don't spend 48 hours of re running and smearing for no reason when I'm not even close. Which I wasn't.


Appreciate the explanations and corrections. Now I'll play around between the 2.5 I know works and 4 LPH to see what I can get away with.

[shadylane]

22 gallon charge of 35% UJSSM low wines.

I'd put less in the boiler so there's more head space.
The reason is the extra distance will let droplets from the boiling lowines to fall back to the boiler instead of being carried up and out on the vapor. Entrainment is particularly bad when pot stilling since there's only one distillation taking place.

[Sporacle]

My opinion ontake off rate for a pot has changed, I believe Yummy pointed it out in another thread. Take off rate should be relative to the boiler charge and time. So the whole run should take; and this is only my opinion, somewhere around 6 hours from first drops.
SW made a really good point about power input and riser size.
If you have the correct power available and a suitable sized boiler and riser a run on a 10 gallon boiler should take the same amount of time as a 30 gallon boiler, if you have the ability to heat and condense.
The 10 gallon still charge and the 30 gallon still charge have the same percentages of desirable fractions as each other , just in different volumes.
Having said that you could collect in jars 3 times as large and at 3 times the rate as you would of with your 10 gallon charge as long as the 30 gallon boiler and riser was up to handle that input and output.
Just my thoughts