My Electronic Still Controller

[funkyphill]

Hi guys, Just thought I would share some details of my still controller I put together.


So basically, as you can see from the photo above, it consists of 4 mains parts.
1 - A programmable PID controller for the heating elements
2 - A Heating element power controller
3 - A vapor temperature monitor
4 - Coolant, fans and pump switches and a wort pump switch.
5 - A temperature data logger

Item 1 has a custom program installed that turns on the heating elements and once the wort reaches near boiling point (aprox 80 degrees for the abv I brew) it turns on a pulsing alarm to tell me to go check on the system. At the same time it turns on the coolant pump which is operating off 12v supplied by a computer power supply installed into the controller. At this time Item 2 allows me to control the amount of power being output by the heating elements (anywhere between 4800W and aprox 100w). The PID is then also programemd to switch off the element and turn on the alarm once the wort has reached 98.5degrees (which is where I usually stop my run).

The second PID (item 3) is used to monitor the vapor temperature and sets of a horrible loud alarm should the temperature of the vapour reach outside predetermined parameters (usually >79degrees C).

Note that both alarms have override switches which allow me to turn off the alarm sound but leave the LED illuminated.

The data logger is there so I can check the run afterwards and ensure that the system remained within the desired temperatures. This part is actually somewhat redundant now that I have the controllers installed. It was more used during the testing phase of the build.

Now I know some of you will say that it loks like a birds nest of cables inside. Please note this this build has only been running for a few months and I have not done much cable management inside to allow for easy changes as the build progressed.

So far the system has been operating great and has allowed me to do other things while a run is going and not have to check up on the system constantly. Next build will be an automated cutting machine that will change collection vessels along a run.

[Dominator]

I think a lot of people on this forum are not real keen on automated systems as they can get you in trouble. I personally think they can be great with the right controls.

One thing I would add is, some kind of alarm that locks out the heating elements if there is a problem with coolant flow or temperature. That way if there is a problem with the cooling system it will shut the heating down and you won't have ethanol vapors pouring out of your still. Again controls would need to be in place, if a jar was to fall you have a highly flammable liquid on the loose. No different to pouring petrol around your shed.

[funkyphill]

Hi, yes I forgot to mention that the high temp alarm also shuts off the heating element. I agree with your points about safety though. I would still never leave the house with a run going.

In terms of a jar falling over, I have been experimenting using a capacitive proximity sensor to sense the levels inside of the collection vessel. Nothing that is fully operating yet but the plan is to use an arduino platform with it to monitor the levels in the collection vessel. That part of the system might take me a little while to get around to though.

[punchy21]

Cool work funkyphill :handgestures-thumbupleft:

[Kimbo]

I think its bloody awesome :clap: :clap: :clap: :clap:

[Dominator]

Sweet, very cool mate and I must admit I am quite jealous.

I don't know a lot about electronics but could you measure vessel level simply by weight? Then have a alarm if the weight does not increase by 'x' amount over time.

[RJB510]

Very nice mate,
I am planning on doing something very similar to you with my setup i'm building now. Your rig is inspiring!

I'm wondering If I could pick your knowledge a bit?
The question I have is, what type of PID controller did you use for each process, as i figure they are different ones?
Initially I was just going to buy one that I can monitor vapor temps with a thermocouple at the top of my column and wire it to shut off or start a pump for cooling. But the more I look into it the more I find different types of PID's and I might as well start looking into it a bit more to get the right one.
Some have SSR output and Relay output. Some with SSR and AL2 outputs etc. All with alarms etc.
Given you seem to have the experience with them, what ones should I be looking at?

What is the difference between Relay output and SSR output (are they not both relays?) and the AL2 output if you know? I'm just looking at the cheap Chinese PID's from eBay.

[L'ambeq]

Hello RJB 510,

Please excuse if I make a mistake, I am new here and this is not my language I use to speak and write.

I built and use a very similar construction since 4 years and it's a very good work with it!

If you want to build something like that please remind the warnings on top!

There are a lot of programmable PID controllers available, I( am using an EUROTHERM 2132, funkyphil used a similar one) chose a cheep one and look for SSR output, in combination with the PID it's the softest and optimised way for Temp control! (Saves life time of switches and elements, provides a controllable flow!)

The additional switch output is to protect to overheat the system if the SSR breaks and makes a continuous output!

I have an additional waterbath low level sensor integrated in line to the switched output.

If I learn how to post my wireing diagramm and a picture of one of my stills I'll do it if you'r still interested in.

Funkyphill did a very good job, I wonder if he uses a waterbath in his still, as I mensioned I am not so confirm with english expressions!

With digital controlled regards

L'ambeq

[cunningfellow]

Hi, yes I forgot to mention that the high temp alarm also shuts off the heating element. I agree with your points about safety though. I would still never leave the house with a run going.

In terms of a jar falling over, I have been experimenting using a capacitive proximity sensor to sense the levels inside of the collection vessel. Nothing that is fully operating yet but the plan is to use an arduino platform with it to monitor the levels in the collection vessel. That part of the system might take me a little while to get around to though.

If you need help with electronics type things with microcontrollers I can lend a hand and also in Brissy

[RJB510]

Thanks for the reply's.
I'd love to see a wiring diagram, I'm actually experienced in wiring electronics and playing with resistors and relays and all that sort of thing. but it's all the different PID's and in particular Chinese brand/made one's I'm not sure what is best. I think I'll just get any cheap ssr output one and go from there.

I like the idea of being able to use it for brewing also.
I guess they're all going to be pretty much the same unless I get an Auber brand one which can be pretty pricey.
I did see that they listed one for distilling though which looked good. But given everyone seems to think they're bad for distilling I might just get any cheap one and play!

[Bandicoot Wrangler]

This kinda thing is really interesting. I have been thinking about a miniature continuous still but haven't put anything on "paper" as yet.

What sort of wort pump are you using? I have had a bit to do with bellows pumps back in the day of wet chemical photo labs. They have some limitations with particulates clogging the valves but would offer fine enough low flow rate control. The other alternative is peristaltic pumps from medical infusion / drip equipment. They would be perfect and you might find them in a salvage yard where they would probably not fetch too high a premium. New they cost thousands.

Good project ..

[L'ambeq]

Hello RJB510,

here you can see an overview of the wiring from my still. Contacts have no numbers because this depends the type of thing you have available in your country!

My still has a waterbath outside, (sry I don´t know how you would call that), but for this I have a water level control to protect the temperature sensor running dry

I also have installed a temperature high limit to protect the SSR against high temp!

If you have questions please ask and note the safety advices on top!

Because I do not know how to add a picture into a post I have attached it

[L'ambeq]

Hello RJB510,

this is the cabinet which belongs to the drawing, ready to fix at the still.

[Farmhand]

How exactly are you controlling the power to the elements, PWM to the SSR ? I was thinking of using some mosfets, IGBT's or SCR's but I guess relays can handle the most power.

Cheers

[L'ambeq]

Hello Farmhand,

the Eurotherm controller I use has a self optimising mode which I used initially.

The output is PID like working direktly to the SSR and is able to keep the temperature of my waterbath in a 0, 5*C range!

This temp has to be 3-4*C more than I need to let the spirit run between dropping and running depending the kind of mash is filled in.

It is possible to cut methanol off and to stop at 90, 5*C steamtemp

The controller is able to increase the setpoint on a ramp but I don't use this function because this is different for different kinds of mash, I increase the setpoint manually 1-2 degrees every half hour +/-

I'll try to post some more pictures here to show how I buil some sensors and what else is necessary to work with a waterbath!

If you have questions feel free to ask!

Cheers