Distilling at altitude Control and Feedback

[dtashmore547]

Hi
I have been distilling for the last year and a half and put together this device to show the temperature of both the neck and keg of my still, also as I live at 1500 meters I have included a BME280 to calculate the boiling point of methanol, ethanol and water so I have an idea what the still is producing at any moment, there is also an output to control an SSR for the 2 KW internal heater. I included a switch to select different displays.
any improvements or suggestions would be appreciated, so far all seems to be good although one display to try and predict the breakpoints between foreshots, heads, hearts and tails has never been utilized as it looks irrelevant in practice.
I assembled the hardware on a through hole prototype board, the unit has a DV20400 4 line by 20 digit LCD display, BME280 humidity sensor, ESP8266 D1 mini and a small 220V to 5V 3 watt supply module.
The ESP8266 was programmed with the Arduino programming interface so the text document will need renaming sketch_distillcontrol.ino before opening.

 

[dtashmore547]

update to the project, missed out the output to the two temperature sensors on the diagram.
The tester is to determine the addresses of the two temperature sensors and assign them to the correct place within the code, rename to .ino and run in Arduino.
DeviceAddress TopHeat = {0x28,0xFF,0x64,0x02,0xE8,0x3F,0xF3,0x00}; //change the addresses between the curly brackets to the ones found in the test
DeviceAddress BotHeat = {0x28,0xFF,0x64,0x02,0xE8,0x38,0x43,0x5C}; //according to position, TopHeat = neck temperature, bottom heat = boiler temperature.

 

[IAmPistolPete]

Temperature datapoints can be useful for reference for repeatability but keep in mind you cannot run a still by temp. I assume you are running a pot still, but regardless, you run a still by power[watts/BTUs] to achieve the output rate you are looking for. It also depends on the wash/mash and product desired. For fruit washes[brandy] the best flavors are in the heads/early hearts and for grain mashes[whiskey] the best flavors are in the late hearts/early tails. The boiling temp is a function of the alcohol content in the kettle so you could use it to estimate amount of ethanol you have left to boil off. The vapor temp can give you an idea of the abv of the condensate. But neither should be used to control the heat output, which is why PIDs are a terrible idea for distillation.
So always run by sight and taste.

 

[dtashmore547]

i haven't used the unit for any kind of control other than manual adjustment of element power.
I find the neck temperature gives some indication of when i am at the ethanol product point and therefore at the hearts production, i understand that the still temperature should be able to give an estimate of remaining alcohol but have never tried to use it, i find that the altitude compensated boiling points are quite accurate so i expect that if i get produce at around methanol boiling point it should be a good indicator of any methanol in the output, so far all my produce is much higher temperature in my whiskey, rum and sugar washes, not yet tried fruit, still get rid of the first 50ml (great cleaning fluid)
as to your question it is a small 2 inch reflux still with a 2kw internal heater mounted on a 50lt keg.