dmachura wrote: ↑Mon Jun 29, 2020 4:08 pm
I don't know why pid control brings such vitriol from some members, the technique produces an acceptable product (okay for me) so it obviously works.
I will explain my procedure, but I'm sure most of you already have watched Georges videos know. My column is 2" x 40" copper tube packed with about 20 inches of stainless steel scrubbers. I use birdwatchers sugar wash recipe to make 23 litres which is 10 to 12 percent ABV.
I let my still heat up using the pid to 80F at the top of the column, of course when vapor breaks through the temp rises to over 100F. At that point the pid turns off the power and the temperature drops I then increase the setpoint as the temp drops 10 to 15 degrees at a time until the overshoot gets to about a 150F. at that point I let the pid and column stabilize. I will say at this time my pid controller is tuned so it holds the temperature exactly after a minute or two. I will then increase the setpoint slowly to 170F At this point there will be a slow drip from my condenser of about 1 to 2 drops per second. I leave it here until I collect 50ml of condensate. I throw away the condensate and slowly increase the setpoint to 175 or 178 until I get a steady drip. I leave the temperature unchanged and collect one quart of 180-185 proof liquid it takes about 90 minutes. I then slowly increase the temp to 185F and collect another quart of 170- 175 proof liquid in about 90 minutes. Then I increase the setpoint to 190 and collect another quart at about 100-110 proof in another 90 minutes. Then I shut the still off.
I will also note that my pid uses a ssr and not a scr so I cannot put the controller in manual but it is tuned so it does not cycle the temperature at the measurement point, at the top of the still.
OK, Now I understand your process but you are not giving me all the info I need to understand what is going on.
What kind of reflux still are you using? Simply saying "I have a reflux still" doesn't say much and your description sounds like it is simply a pot still with packing that is possibly getting some passive reflux by running it slow. How is the distillate being refluxed? How are you managing the water to the reflux condenser? I myself run a 3.5" CM (Cooling Management) packed with 40 or so inches of lava rock. I used to run a 1.5" Bokakob, also packed with 40" of lava. Both of them used the same simple, cheap SSR controller to accomplish very high proof. The boka ran slow but produced azeotrope from the 2nd pint throughout the run until the very last jar. The CM does 94.5- 95%, again from the 2nd jar until the very final one, the final jar drops from 94% to 30% in less than a quart and runs very quickly.
As far as watching George's videos to see your process, I have only watched a couple of them and found myself screaming at the monitor when I did because of the bad information he is passing on, so I avoid them.
Would you be open to try making a simple controller and running in a way those of us who make high proof do and see which way is better?
If I had the budget I'd buy one of these PIDs just to run the way George tells everybody to do it and see just what is happening but in all honesty it doesn't sound like a very good method to me but I would like to see exactly what is going on inside the column when run that way.