Arduino Controlled Wort Chiller?

[jcmcdowell]

Anyone have ideas for building a micro controller based system to adjust a flow valve to keep your wort at the right temp as it flows through a Heat Exchanger into the fermenter.

single stage temp controllers are either ON or OFF. So they won't work. You need a variable valve and a way to measure temp and correct the flow rate to get your temp steady.

Hook up a DIY glycol chiller to that and let the automated chiller go...include a oxygenation pickup post temp probe and I wouldn't have to eyeball the thermometer and tickle the flow valve to keep the temps in a safe range.

I'd be really interested in building this if anybody has programming ideas.

 

[muhteeus]

PID? There is quite a few sketches to work off of out there.

 

[jcmcdowell]

OK- I'll keep bumping...

So the heart of it will be a PSV proportional solenoid valve. I'm assuming you'd want one that is DC and works within the range of 0-12v to accommodate the variable voltage output.

Use the PID library to hone in on the temp swings and build in a sampling delay to account for the slower response time.

Reading the temp should be pretty straightforward.

The question: Does the valve control the flow of the wort or the flow of the cooling liquid (glycol, water). If the valve controls the wort- you could potentially have a high flow rate (which is good). If it controls the cooling liquid- you have more control.

WHY BUILD THIS?
1. This stage takes me the most concentrated time in the whole process. Standing there watching my Blichman inline thermometer.
2. I hate all the waste of the cooling water and I don't have vessels reasonably close to the size needed to contain the cooling water- so I want to integrate this with a closed loop cooling system.
3. I want my wort to be hit the fermenter with a couple of degrees of my target temp- not plus or minus 10 degrees.
4. I'm jumping up from a keggle 10 gal to a 1.5bbl system and want the flow rate increased.

Closed loop cooling. A small cheap-o AC can be turned into a chiller and if needed run a two stage cooling (wort cooling liquid runs into a heat exchanger to cool wort then runs through another heat exchanger to drop temp back down enough for chiller (another heat exchanger) to get the temps down quickly. A combination of air cooled- like a radiator; combined with the chiller to bleed off enough heat to keep your wort cool.

Integrate an Oxygenation pickup into the post heat exchange and temp probe. There's plenty of inputs and outputs on an Arduino board- is there a way to integrate Oxygen volume control into the wort? Is it worth it?

Make it mobile. Build it on castors self contained to store or move around the brewery.

 

[muhteeus]

The question: Does the valve control the flow of the wort or the flow of the cooling liquid (glycol, water). If the valve controls the wort- you could potentially have a high flow rate (which is good). If it controls the cooling liquid- you have more control.
.

The valve would throttle the wort side inlet. Slowing the cooling liquid will only slow your thermal transfer.

 

[jcmcdowell]

Any C programmers out there interested in taking a lick at this? I'll build one in September.

 

[muhteeus]

I would help you out, but I had to get assistance on the last Arduino sketch I did just to get it to compile. Then it didn't work. Best of luck!

 

[schematix]

I used to try to single pass through the wort chiller while throttling the wort pump and chilling pump. All I managed to do was stress myself out that it wasn't working consistently.

Have you considered building a system that recirculates the wort through the chiller until you've hit your desired temp? This is purely an on/off task. What I do now is use ground temp tap water (unlimited supply) in the chilling side of the loop to take my wort from 212 down to about 90-100 while the wort recirculates (and whirlpools) back to the BK. With my Therminator this takes about 4-5 minutes. Then I switch my cooling loop to recirculate ice water until the wort in the kettle either hits my desired temp, or at least gets close. Then you can run out straight to a fermenter.

 

[muhteeus]

I used to try to single pass through the wort chiller while throttling the wort pump and chilling pump. All I managed to do was stress myself out that it wasn't working consistently.

Have you considered building a system that recirculates the wort through the chiller until you've hit your desired temp? This is purely an on/off task. What I do now is use ground temp tap water (unlimited supply) in the chilling side of the loop to take my wort from 212 down to about 90-100 while the wort recirculates (and whirlpools) back to the BK. With my Therminator this takes about 4-5 minutes. Then I switch my cooling loop to recirculate ice water until the wort in the kettle either hits my desired temp, or at least gets close. Then you can run out straight to a fermenter.

This is the design I am going to use.

 

[jcmcdowell]

I like the idea but have some concerns...

First- the nice part of that process is you can sterilize your chiller running the near boiling wort through it before turning on ground water.

Being sort of eco-friendly, but mainly hating to pay the water bill- I want a closed loop cooling system to eliminate the water waste.

My concern- their is a certain temp range that the wort becomes very susceptible to bacteria invasion. If you can start the transfer in the 160 F range and get it in the fermenter straight away you reduce your chances of infection.

Maybe with just the lid on this may not be a big issue and the recirculation would be a great way to get the temps down a 100d F before transferring. If the pumps strong enough, it could include that in the whirlpool phase, but I've never had much luck in my keggle system with whirl pooling.

I'm starting a nano brewery in a small town. I'm trying to automate as many simple tasks to free up my brew day. Starting with a 1.5bbl, I expect the days will be long already. If I could manage to hit a button and open a valve, I can work on other things instead of monitoring the transfer closely the whole time.

I prefer to load in the yeast on the bottom of the fermenter and then pump the wort on top. Maybe a quicker option. Fast transfer the wort plus or minus 65d F into the fermenter and then just wait until the wort is temp controlled to exactly 65- then pitch.

I like the Arduino- so I'll keep playing with the idea.

 

[schematix]

I like the idea but have some concerns...

You can easily sanitize all your valves, lines and chiller by doing a 5 minutes recirc with the boiling wort.

This dual-stage cooling is eco friendly. The heat transfer is *highly* efficient from 212 down to about 120. You can do this with minimal water... depends on batch size and ground water temp but i'm thinking this phase can be accomplished with about ~25G of water for a 10G batch. The next 10-20 degrees is less efficient, but not terrible. Over the next 5 minutes you'll go through another ~25G of water, but now you're at 100F. NOW you switch to a recirculating ice water loop and you're recirculating the same ~5G or so until you're done. You could switch to the recirculating loop sooner but then you're just wasting electricity (to make ice) instead of water.

I find this method to be the best I've come up with so far. I'm sure buying a glycol refrigeration system is more "eco-friendly", but comes at a cost. That's how the big boys do it though.