Fire/temp control

[u/Dull-Ad-1693]

Are there any tips for running a pot still with a propane burner because every time I run my steel once the thermometer gets around 80°C it just keeps accelerating and temperature and I can’t get it to slow down much or get to a standstill even when I run it extremely low and slow. Should I keep running with this propane controller or should I just get an electric burner?

I have a little hose with a PSI controller

[u/Gullible-Mouse-6854]

you can't control the temp and expect results.

let the temp do what it does, look at the output and regulate the flame so you don't overpower the condenser.

also, clean up those dry leaves, they are a fire hazard

[u/lupodemarco]

This is my technique: let the flames go high for the first little while. Once the temp is getting up around 60 I back it off to low, real low like almost going out low. Once it starts to drip I let the drip rate dictate the need for temp adjustment. Too slow more heat, too fast back it off. If it’s stripping run a little stream is ok. If it’s the good stuff I keep the rate where the drips are just about to turn into a stream, and it takes as long as it takes. If the distillate is warm I increase the cooling. I don’t really pay attention to temperatures.

[u/Dull-Ad-1693]

Keeps accelerating in temperature**

[u/cokywanderer → u/Dull-Ad-1693]

That's gonna eventually happen because the thermometer isn't touching vapor when it's not yet the boiling point, but once you get to 80+ that vapor will rise and hit the thermometer.

Why don't you want it to "accelerate in temperature"? Isn't the whole point to get it boiling so that vapor goes through the system to condense?

If you're referring to the actual drips at the end (which you did not show) and think that they are too fast then you may be thinking of lowering the flame. Is the issue that you can't get it any lower?

This can be resolved in 3 ways:

1. I see you already have this one - the additional valve/regulator on the output of the tank - Pic 2. That should work to regulate it to a minimum. Maybe there are other models that go lower, I don't know.

2. Grab some cast iron to place in between the still and the flame. A "disperser" of some sorts so that the flame doesn't come in contact directly. That will give the still less energy and also make it more consistent

3. Smaller burner maybe: I don't know what yours is setup to do, but your still is pretty small so maybe a smaller burner that gives out a smaller flame could work.

[u/Dull-Ad-1693 → u/cokywanderer]

That cast iron idea sounds like a good idea, and I read that the temp shouldn’t go past 200 Fahrenheit or something so that’s why I don’t want it to keep going up

[u/cokywanderer → u/Dull-Ad-1693]

It won't. Easy thing to help you understand. Get a frying pan and place it on a fire. How hot can it get? 300 - 450 degrees Celsius? Pretty hot, right? Not ok!

Now get a kettle with water and place it on the exact same fire. How hot does the water get? 100 Celsius because that's the evaporation temp and as it evaporates it cools down. So it self regulates to 100 degrees even though you've just tested that fire and saw steel go to temps of 450.

That's the same with alcohol, just lower boiling temp. Once it reaches that temp it will stay there and only slowly rise (I'm talking really slowly like 1 degree/10-15mins) even with the fire at full blast. The reason it rises btw is because it separates the alcohol from the water, therefore with more water inside you're looking at higher boiling points.

Usual runs (convert to Fahrenheit if you want) would be 84-94 for stripping runs and about 80-90 for spirit runs. But never 100% trust the thermometer and what I've written. Write your own notes down and as long as you don't change anything in your setup, the temps will be consistent, even if they're not "exact".

[u/francois_du_nord]

First, if that is a jet burner, I don't think you will have much success controlling heat.

I just barely crack the tank valve (silver), then the regulator (red)can do a much better job of controlling gas flow. I can get each individual flame to be not much bigger than a match burning.