Trang and My Lan were out of town over the weekend. While I’ve mostly forgotten what it’s like to have the place to myself, I did manage to keep busy working on an academic manuscript and, of course, the brewery.
Between the broken cabinet fan, the conversion from thermoelectric chips to a tube mounted water heater, and the conical installation, the cabinet has been in pieces for weeks. Fortunately, it’s slowly coming back together.
I replaced the thermoelectric chips with a water heater mounted in a stainless steel tube. It’s only a 1200 W element but is much more powerful than the chips. I tested the system at only 1% power and the fluid temperature increased 10 degrees Celsius in about 30 seconds. Nuclear winter won’t keep me from my ales.
I’ve also gone back to a smaller aquarium pump in a bucket. The Denner magnetic drive pump I had in place before was a little noisy and overpowered, so I’ll reuse that for my clean-in-place system. The bucket mounted pump is quiet, adequate for the system (I measure a flow rate of 30 mL/s), and can fit inside the refrigerator. Putting the fluid reservoir in the refrigerator might also allow me to make cooling more efficient.
Secondly, I redid the wiring for the whole system. I run the power for the pump and heating element directly through the wall of the refrigerator. The thermosensor wiring is all new, with pre-terminated RJ-45 cables that don’t have to be secured with rubber-bands to maintain a connection. They’re all connected through my OneWire hub circuit board and providing reliable signal. I just need to tidy up the cables.
The cabinet fan still doesn’t work although I’m sure the controller is providing power. The immersion coil may make the cabinet radiator obsolete in the summer, so I’m not in a hurry to fix it. Removing the thermistors frees up a second fan terminal for the controller, so I may put a large fan into the refrigerator to increase heat transfer at the copper coil inside. I’ll wait until I can run a cooling test with the conical in place to see just how cold I can get 5 gallons of water.
Once my CIP fitting arrives, the conical will be ready to go into the cabinet. I’ve put my Chugger pump on a temporary mount. All I need is to put my burner on wheels and finish the counter-flow heat exchanger, and the back end of my brewery will be finished!