Hello everyone, just thought I would share some pics and info on an old brewing project of mine. I use the same fridge as a dispensing/fermenting and lagering. When I am fermenting (lagers only in the fridge as my cold cellar is perfect for ales) unfortunately my serving temperature is also going to be around 9 deg C. When I am lagering I usually lager around 2-3 deg C which also is my normal serving temperature.
- Old Fridge
- 4-20ma Temperature transmitter 0-50 deg C
- A-B SLC 5/03 with Rack
- Analog Input Card
- Triac Output Card
- Motor Starter
- Fuse Block
- DIN rail, wire, terminal blocks
- Lightbulb socket
How it's all connected:
- Fridge dial set to FULL COLD. power cord is cut and connected to motor starter which is driven off of PLC output.
- Temperature probe is inside fridge and is wired to analog input card.
- Light socket (with 40W incandescent bulb) is wired to another triac output
- Panelview is connected to processor.
- Beer taps (couldn't afford real taps just yet so I used picnic taps) and kegs and gas distribution block are all inside fridge, CO2 tank and regulator outside.
- Real taps & Drip Tray!
- Mount Panelview in Door
- Yeast bank in Freezer Part of Fridge
How it works:
The PLC program is constantly looping looking at the current temperature and the temperature set point. If the current temperature is below the setpoint, the 40W light turns on inside the fridge (I found 40W is just enough to keep a fridge in the garage in winter, -10 deg C ambient controllable). If the temperature is above the setpoint, the compressor (via starter) is activated. The program is also looking at ramp rates and will prevent the temperature from changing too fast in either direction by means of a intermediate setpoint that is calculated by using the user adjustable ramp rate. Through this setup I can easily maintain (within 0.5deg C) the temperature inside the fridge but also gently ramp up or down the temperature (at any rate I choose) to match a given fermentation schedule.
Because of the industry I work in, I had all of these parts available and free. If I didn't have all this stuff, I would probably use some sort of microcontroller such as the Arduino or possibly a cheap KOYO (see automationdirect.com) PLC and touch screen. If one is really wanting to get into automation, the KOYO or the PLC I used would be more than capable of running an E KEGGLE, HLT (with PID controls), Lagerator/Fermenters and possibly even a semi automatic bottling line.