Page 1 of 1

PID controller complete

PostPosted: Sun Oct 27, 2013 9:24 am
by trolleyed
Hi all, thought i'd post this up for general interest and to add to the growing list of people using PID controllers for their boilers.

I'm still in the process of completing the still itself (2" Boka for now), so I haven't put any load on this unit to see if the SSR heatsink is adequate. I'll be monitoring the heat output closely when I do my vinegar/cleaning runs initially to see how everything goes. There's no airflow when the cover is on, if this becomes an issue I can create a vent and mount a small fan on the right hand side quite easily.

All work inspected by 2 electrical engineers, all given the A-OK and the only recommendation is to earth the DIN rail, which i'll do today. I tried to make this 'modular', the fantastic keg element I got from the 5SD store here will plug into the GPO you can see on the left side. Using the earth pin in the heating element which runs straight from the power input you can see in the pic. Had to tie a knot in the cable as the black plug thing (Wtf is this called) that screws into the box was too big. Used 2 extension cables from Bunnings, cheaper this way as you get both ends and a bunch of cable for $3, instead of one end for $5!!

Re: PID controller complete

PostPosted: Sun Oct 27, 2013 9:48 am
by punchy21
Looks good mate, just run an earth to one of your SSR mounting screws also :handgestures-thumbupleft:

What PID did you opt for?

Re: PID controller complete

PostPosted: Sun Oct 27, 2013 11:19 am
by Brendan
Your build looks of good quality mate :handgestures-thumbupleft:

I still don't understand the use of PID controllers in distilling though...considering that adjusting the power input does not change the temperature of a boiler with alcoholic components, only the output rate...? :think:

Re: PID controller complete

PostPosted: Sun Oct 27, 2013 1:54 pm
by Canadoz
Brendan wrote:Your build looks of good quality mate :handgestures-thumbupleft:

I still don't understand the use of PID controllers in distilling though...considering that adjusting the power input does not change the temperature of a boiler with alcoholic components, only the output rate...? :think:


You just answered your own question. :clap:

Output rate/speed which affects smearing in a potstill and coolant flow requirements in a reflux still.

Re: PID controller complete

PostPosted: Sun Oct 27, 2013 3:04 pm
by Brendan
Canadoz wrote:
Brendan wrote:Your build looks of good quality mate :handgestures-thumbupleft:

I still don't understand the use of PID controllers in distilling though...considering that adjusting the power input does not change the temperature of a boiler with alcoholic components, only the output rate...? :think:


You just answered your own question. :clap:

Output rate/speed which affects smearing in a potstill and coolant flow requirements in a reflux still.


But the fact remains that a lot of 'newish' people rig up PID controllers to temperature sensors...

So you're saying that the OP has created this unit to be wired up with output flow rate sensors, to automatically adjust both the power input and coolant flow rates?? :wtf:

Re: PID controller complete

PostPosted: Sun Oct 27, 2013 3:22 pm
by Canadoz
Brendan wrote:
Canadoz wrote:
Brendan wrote:Your build looks of good quality mate :handgestures-thumbupleft:

I still don't understand the use of PID controllers in distilling though...considering that adjusting the power input does not change the temperature of a boiler with alcoholic components, only the output rate...? :think:


You just answered your own question. :clap:

Output rate/speed which affects smearing in a potstill and coolant flow requirements in a reflux still.


But the fact remains that a lot of 'newish' people rig up PID controllers to temperature sensors...

So you're saying that the OP has created this unit to be wired up with output flow rate sensors, to automatically adjust both the power input and coolant flow rates?? :wtf:


Sorry if I came across facetious, I didn't mean it that way :oops:

In answer though:

"Ain't nobody got time for that!" I meant it in a more indirect sense:

I'm not sure precisely what OP has done, but I could see using a PID with a temperature sensor to automate the process of high speed boil up using all available wattage and then leveling off the power input to avoid pushing all the vapor out at an accelerated speed once the vapor begins flowing. This would accurately allow the foreshots and then heads to collect at the optimum speed so they compress as much as possible.

Not that I've done any of that but it sounds good in theory.

Re: PID controller complete

PostPosted: Sun Oct 27, 2013 4:22 pm
by trolleyed
Hmm thought I posted a reply but it seems to have disappeared.

Thanks for the comments, yes I am very new to distilling. I haven't done any runs yet :) Might do the first vinegar cleaning run tonight.

This PID controller was born when my electrical engineering friends went over the temperature controller schematics on this website. It was a case of "yeah, that'll work, but this is a much cooler way to do it..." i'm always up for cool things, so there you have it. And yes once everything is boiling I don't need full power anymore. And i'll be able to use it for more complicated purposes when i'm more experienced, I'd love the challenge of doing a fully automated setup for everything from taking cuts do managing cooling. That's a long way off in the future!

I need a proper work bench instead of doing everything on the garage floor :)

Re: PID controller complete

PostPosted: Sun Oct 27, 2013 4:40 pm
by Brendan
Yeah I should re-word my statement...I don't understand why anyone would use PID control in home distilling.

As someone who understands PID control, I can see their value in a commercial distillery with thousands of dollars of control systems. But I worry on a home level, that people want set and forget equipment that will do it all for them.

Although it revolves around science, it is very much an art :handgestures-thumbupleft:

Re: PID controller complete

PostPosted: Sun Oct 27, 2013 4:44 pm
by Brendan
trolleyed wrote:Hmm thought I posted a reply but it seems to have disappeared.

Thanks for the comments, yes I am very new to distilling. I haven't done any runs yet :) Might do the first vinegar cleaning run tonight.

This PID controller was born when my electrical engineering friends went over the temperature controller schematics on this website. It was a case of "yeah, that'll work, but this is a much cooler way to do it..." i'm always up for cool things, so there you have it. And yes once everything is boiling I don't need full power anymore. And i'll be able to use it for more complicated purposes when i'm more experienced, I'd love the challenge of doing a fully automated setup for everything from taking cuts do managing cooling. That's a long way off in the future!

I need a proper work bench instead of doing everything on the garage floor :)


Haha that's not your fault trolleyed...as an electrical engineer myself, I understand that's what engineers like to do 8-} Over-complicate things...

Re: PID controller complete

PostPosted: Sun Oct 27, 2013 4:56 pm
by Linny
Lol . I know and seen someone use a pid controller on a bubbler. Problem is that it changes the power and the reflux goes haywire if your not watching closely

Re: PID controller complete

PostPosted: Wed Nov 13, 2013 8:15 am
by trolleyed
Bit of an update, after a few vinegar cleaning runs, did a TPW using my fresh Boka in pot-still mode (no packing, full open needle valve).

The controller worked a treat, I set the PID to 85 degrees so it just kept the element on 100% for the whole run. I had the thermocouple inserted just below the top plate, so it was exposed only to vapour. The whole run took around 3 hours for 25 litres, I stopped it when the vapour temp was around 83 (can't remember the exact figure), this was a few minutes after the output started to go cloudy, which from my reading is going too far into the tails. The ABV wasn't terribly low for the last run, I had it in a 5 litre jar by that point and didn't get around to measuring the ABV once it had cooled off. I watered some of the 'middle' (i'm not confident in calling this hearts) product down to 40%ABV and had a taste, and wow i'm surprised how smooth this is. It smells strong as hell, but no nasty burn or aftertaste like so many commercial vodka's i've tried. And that's just a quick and dirty stripping run! The only issue I had was the $20 ebay special stainless needle valve leaking. A bunch of flour paste sealed this up.

Anywho, kicked off 40 litres of TPW last night which will be good for a stripping run on the 23rd. I'm going to combine the above stripping run for a spirit run using reflux for the first time on the 24th. All systems are a go :happy-partydance: