Pot Still Vapor Temperature

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Corsaire
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Re: Pot Still Vapor Temperature

Post by Corsaire »

Brew bama wrote: Sun Aug 02, 2020 10:49 am
jedneck wrote:Adding power is not adding heat
???? [emoji1021] I give up.

Running power thru a heating element produces heat. A heating element converts electrical energy into heat through the process of resistive (otherwise known as Joule heating). The electric current passing through the element encounters resistance, which produces heat.
Of course power produces heat, but that doesn't neceserily increases temperature.

Look at it this way:
If you boil water it turns to steam, but the water stays at 100C.
You can throw more power at it, turn up the gas, throw another log on the fire, whatever. All it does is increase the rate steam is produced. The liquid still holds 100C.

In distilling you don't manage temps, you manage vapor production.
In a pot still the rate of vapor produced dictates how much smearing happens.
In a reflux column it contributes to reflux ratio.

Add to that that yes, pure ethanol boils at whatever science books dictate but if you add other compounds to the mix all sorts of crazy bonds happen.
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Re: Pot Still Vapor Temperature

Post by Hambone »

Does the PID work better with glass thumpers or silicone gaskets?


Lord, I apologize for that comment....
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Experience is usually the result of bad judgement..
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Re: Pot Still Vapor Temperature

Post by kimbodious »

Great clear concise explanation Corsaire!! It should be required reading.
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Re: Pot Still Vapor Temperature

Post by bluefish_dist »

Brew bama wrote: Sun Aug 02, 2020 7:22 am I guess we simply agree to disagree.

Not sure how bumping up a PID controller is any different than turning up heat any other way, manual or otherwise, but OK.
It’s not, but it’s horribly inefficient.

Why have a PID then change the set point to keep the rate of vapor production the same? The whole point of PID is to control a process at a set temperature. Unfortunately this doesn’t exist is the process of boiling wash/wort. The boiling temperature of a wash/wort is constantly changing and it always goes up. Because of this the power input is always going down. To overcome this, the user has to keep increasing the temperature set point to keep the same vapor production rate.

Controlling power input almost directly controls the rate of vapor production which is proportional to vapor speed in the column. There are slight changes since alcohol and water don’t require the same amount of energy to change phase, but it’s close enough we can ignore this. If using wash/mash boil temp it might change 15-30 deg during a run. That’s a lot of adjusting on a PID to do something that requires no adjustment using a power meter.
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Re: Pot Still Vapor Temperature

Post by Brew bama »

bluefish_dist wrote:
The boiling temperature of a wash/wort is constantly changing and it always goes up. Because of this the power input is always going down. To overcome this, the user has to keep increasing the temperature set point to keep the same vapor production rate.
^^^^ Exactly. ^^^^

This works like a charm. Is very easy to do. Makes the process interactive. ...and is fun.

Why anyone other than me would give two craps how I make what I have work to the extremes this has taken is hilarious. [emoji23]

Take it easy folks. Have fun and don’t take this so serious.

Cheers!
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Re: Pot Still Vapor Temperature

Post by LWTCS »

Extreme?
Not extreme at all.
Fact is , more or less daily fodder (more recently).
It's why we're here no? To talk about all things distilling.

You wanted us to be part of your education and journey or you wouldn't have posted, no?
It just sounds like you weren't expecting to be called out by the self policing community.
Trample the injured and hurdle the dead.
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Re: Pot Still Vapor Temperature

Post by Brew bama »

LOL. Ok.

Your world. I’m just hangin out in it.
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Re: Pot Still Vapor Temperature

Post by bluefish_dist »

Brew bama wrote: Sun Aug 02, 2020 3:10 pm
bluefish_dist wrote:
The boiling temperature of a wash/wort is constantly changing and it always goes up. Because of this the power input is always going down. To overcome this, the user has to keep increasing the temperature set point to keep the same vapor production rate.
^^^^ Exactly. ^^^^

This works like a charm. Is very easy to do. Makes the process interactive. ...and is fun.

Why anyone other than me would give two craps how I make what I have work to the extremes this has taken is hilarious. [emoji23]

Take it easy folks. Have fun and don’t take this so serious.

Cheers!
We are just trying to help you from wasting time and $$. Come back after a few hundred runs and let us know if you still run this way.

IMHO a simple power controller is awesome. Simply use as much power as you have for heat up, then back off to start your run and not puke. One whole adjustment, no tweaking required. No need to figure out what temperature is required to boil the abv in the boiler.
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Corsaire
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Re: Pot Still Vapor Temperature

Post by Corsaire »

If you have fun with it then it's all good.

But if you can, just swap out the pid for a power controller and see if you notice a difference. Just for shits and giggles.

I get being inefficient. I used to commute an old honda bike that needed oil changes every 3000kms and still had points ignition. Kick start only too.
Still love that thing.

Problem is a lot of new distillers get sucked into the temperature trap and think a pid is the best possible controller, which it isn't.
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Re: Pot Still Vapor Temperature

Post by NZChris »

There's been a lot of newbie PID owners coming here since a newbie started posting distilling videos on Youtube without bothering to do his homework first.
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Re: Pot Still Vapor Temperature

Post by Brew bama »

@bluefish_dist
@corsaire

I don’t doubt one and done power is a better deal but it’s just not in the cards right now. Maybe later. Until then I have to run what I brung.

Cheers!
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Re: Pot Still Vapor Temperature

Post by NZChris »

Some PIDs come with the option of manual control of the output. Check if yours does.
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Re: Pot Still Vapor Temperature

Post by Grandad7 »

TDick wrote: Sat Jul 25, 2020 9:05 am
ParrotHead wrote: Fri Jul 24, 2020 8:23 pm You guys are awesome. Maybe I just needed someone to tell me to stop listening to all the temperature folks writing the books.
But
ParrotHead wrote: Fri Jul 24, 2020 8:23 pm I do think that around 90 deg C is a good marker for me to take cuts for heads-hearts transition.

Just looking for answers is all.
I read this thread because I have a copper pot & thought I'd learn something new.
I shouldn't have done that - folks THAT KNOW are repeating the same thing written here years ago.
Because they work.

I have a thermometer and yes I watch it out of curiosity. Even though I KNOW it means absolutely nothing compared to LISTENING to my pot and putting my hands on it.

It would appear you are looking for the answers you already believe to be correct.

Even when everyone here is telling you they are not.
:roll:
I guess some folks, including myself, need/want some form of reassurance.
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Re: Pot Still Vapor Temperature

Post by Yummyrum »

Grandad7 wrote: Sun Aug 28, 2022 10:20 pm
TDick wrote: Sat Jul 25, 2020 9:05 am
ParrotHead wrote: Fri Jul 24, 2020 8:23 pm You guys are awesome. Maybe I just needed someone to tell me to stop listening to all the temperature folks writing the books.
But
ParrotHead wrote: Fri Jul 24, 2020 8:23 pm I do think that around 90 deg C is a good marker for me to take cuts for heads-hearts transition.

Just looking for answers is all.
I read this thread because I have a copper pot & thought I'd learn something new.
I shouldn't have done that - folks THAT KNOW are repeating the same thing written here years ago.
Because they work.

I have a thermometer and yes I watch it out of curiosity. Even though I KNOW it means absolutely nothing compared to LISTENING to my pot and putting my hands on it.

It would appear you are looking for the answers you already believe to be correct.

Even when everyone here is telling you they are not.
:roll:
I guess some folks, including myself, need/want some form of reassurance.
Yeah , it's called your tongue . It's the sensor thing in your mouth that detects nice things or not .
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Re: Pot Still Vapor Temperature

Post by BlueSasquatch »

Bit of an old thread.

Best thing I've done was run with a copper pot-still with 0 bells and whistles. There are alot of small things sure, but you just turn on the heat, and collect what comes out. Fores, Heads, Hearts, Tails. The order doesn't change on you, use small jars, they make the cuts for you.

I mean now, I want all the bells and whistles, but that's after building a solid foundation without them. The best tool for this hobby should be yourself.
"In the silence of the study one can discuss theories, but only in practice one becomes an artist" - Meunier
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Re: Pot Still Vapor Temperature

Post by Saltbush Bill »

BlueSasquatch wrote: Mon Aug 29, 2022 6:08 am The order doesn't change on you, use small jars, they make the cuts for you.
BlueSasquatch wrote: Mon Aug 29, 2022 6:08 am The best tool for this hobby should be yourself.
:thumbup: :thumbup: +1
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Re: Pot Still Vapor Temperature

Post by drmiller100 »

Brew bama wrote: Sun Aug 02, 2020 10:19 am Physics?

A pot of liquid doesn’t care how the heating energy is applied. Whether that’s with a wood fire, propane, an induction cooktop, electric stove, or water heater element inside the pot.

A temperature output device registers temperature regardless of whether that temp is provided by a mercury ‘stick’ thermometer, an analog gauge, or pt100 probe with remove readout.

When I plug a temp probe into a box that provides a temperature readout, and based on that perceived temperature, calculates power required to raise the liquid from that temp to a higher set value by providing power to a heat source, I disagree that all of a sudden I am breaking the laws of physics.

Whether I am turning a dial or pushing a button with an up arrow on it likewise should not matter.

It is exactly the same as me manually looking at an analog temperature device and turning up the stove or adjusting a propane burner.

I understand that at any one point in time the PID control can set the steady state, but as soon as the alcohol in the wash drops, the steady state, and therefor the controlling characteristics of the system change. As the run continues using several cues such as the parrot, the temp, and sensory analysis (sight, smell, taste), I bump up the SV.

I’m sorry but I don’t see how I’ve broken any laws of physics.
There are lots of people on this site who believe a pot of boiling water has different temperatures in the pot. Some believe you can separate out the mixture in the boiling pot by slowly bringing the pot up to temp.

There are people who believe you can change the boiling temperature of the pot by using a pid to set the boiling temperature.

Most seem to believe the ONLY reason to use a pid is to lower the boiling temperature of the pot.

They already KNOW it all!!!!

All that being said I'm a HUGE fan of temp gauges with a reflux column going for azeo.

I don't see how a temp gauge is going to help if you aren't after azeo.
Now I know how you claim azeo so easy, it's based on a meat thermometer. :lol:
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Re: Pot Still Vapor Temperature

Post by bluefish_dist »

drmiller100 wrote: Mon Sep 26, 2022 7:05 pm
All that being said I'm a HUGE fan of temp gauges with a reflux column going for azeo.

I don't see how a temp gauge is going to help if you aren't after azeo.
Use of thermometers in a still is always a big topic of discussion. Those that run pot stills tend to say they have no use and some who run columns say they can be useful. Imho both are correct. When I ran my still configured as a pot, I had no temperature measurement device. Not needed and doesn’t really tell me much in regards to my process. When I ran as a column, I controlled reflux rate based on temperature. I found temperature to give me a quick way to see how well the still was working. Temp going up, I am pushing too much heat, or too fast a takeoff (not enough reflux). Going down, I could run faster, more heat, faster takeoff. Fwiw I found changing power was not a good way to control reflux or abv, number of plates and reflux rate were far more effective.
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Re: Pot Still Vapor Temperature

Post by BlueSasquatch »

I must still be an amateur, with my pot still on propane, I have a sharpie marked for how much gas to feed, and it sits at that spot, for 4+ hours, never changing, and what comes out is a nice "pencil-lead" stream, that never really changes. I know columns are a bit different, but Christ on a cracker, you can just set the fuel feed and leave it alone. Maybe people feel the more they do during a run, the more skillful they are?
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Re: Pot Still Vapor Temperature

Post by SDEngr1 »

I make all my cuts based on taste while distilling. I take 2 ml of distillation and add 3 ml of water and taste. I can detect transitions within a few ounces of one another. However, I am running a reflux still and typical proofs coming off are around 187. The dilution and tasting gives me the best window into where I am at during the process.
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Re: Pot Still Vapor Temperature

Post by bluefish_dist »

BlueSasquatch wrote: Tue Sep 27, 2022 5:34 am I must still be an amateur, with my pot still on propane, I have a sharpie marked for how much gas to feed, and it sits at that spot, for 4+ hours, never changing, and what comes out is a nice "pencil-lead" stream, that never really changes. I know columns are a bit different, but Christ on a cracker, you can just set the fuel feed and leave it alone. Maybe people feel the more they do during a run, the more skillful they are?
That’s pretty much how a pot still runs. I did a little more than that, but that was simply reducing power for the first 30-45 min for a hot break, then ramping up power a little more.

Column isn’t a lot more complicated, bring to boil, stabilize with no takeoff and low power. Take off fores cut at high reflux rate (4 turns on valve) and a little more power, for me that was 1 gallon (100-110 gal of wort). Then reduce reflux (10 turns/half open), wait for temp to climb to my desired temp. Once it hits temp, increase reflux (close valve 1/2 turn). Repeat until I get to 2.5 turns open. After getting to 2.5 turns, when I hit temp, Reduce power by 1000w (max of 12kw). Repeat power reduction until down to 8kw, then shut down. Temp depended on what I was making.

The skill is really in cuts, but even then I found most people could get within a jar with some basic guidance. For cuts I would cover with paper towels and wait 24 hrs. Then dilute 1 tsp water to 3/4 tsp spirit in a sample glass to taste. I would have between 15-30 1/2 gallon jars.
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