The system consists of 3x 55 gallon stainless steel tanks purchased on eBay. Yes, you can buy these on ebay! They’re just stainless steel drums and of course need fittings welded on.
Pumps are 120v, 17 GPM models made by March. These are controlled using Omron 35A relays.
Valves and Actuators
Valve actuators are Belimo AF-24 proportional and on/off valves. These run off 24VDC or 24VAC. The proportional valves accept a 2-10vDC control signal. This is fairly standard among actuators and we also have some Johnson Controls
actuators with identical specs except that unfortunately they are not powerful enough to open our ball valves. Actuators were all purchased on eBay. The hard part is mating these valves to your ball valves. The circuit to control
these using an Arduino 5v PWM output is reproduced on the schematics page.The ball valves were also bought off eBay. Tip: verify that the valves were not used with caustic fluids. Even if the valves started life as food grade, you
won’t want to use them if they make your beer smell like chemicals!
Cooling & Filtering
Cooling is performed using a stainless steel 30 Plate Heat Exchanger off eBay. A filter is required before the heat exchanger to prevent clogging the passages with solids. Brewers hardware has a filter. Note that this filter
won’t filter out all solids from a 2 barrel batch; you’ll have to place the outlet from your boil kettle appropriately and also whirlpool to leave as much of the solids in the kettle as possible.
Heating is via 240volt screw in immersion electric heating elements off Amazon.com. There are many models available, ranging in price from $3 upwards. Generally, the more surface area they expose, the better, since there is
less chance of creating hot spots in the liquid being heated.The heaters are switched on and off via 40 amp Solid State relays from Jameco.com. These accept a wide input range.
Piping, Tubing, and Fittings
Tubing is 3/4″ high temp silicone tubing from McMaster-Carr. Look up part number 51135K412 for example.Tubing is mated together using tri clover clamps and fittings. There are handful of places to buy these; try Brewers hardware.
Electronics, Sensors, and Power Supply
The brain of the project is made of an old PC running Processing 1.5 (NOT 2.x) and an Arduino Mega2560 running Firmata. The ControlP5 and Arduino libraries are installed on the PC.
Temperature is via the BCS-460 thermistor with tri clover fittings for the BrewTroller project.
Level sensing is performed via MPX-5050GP differential pressure sensors from Digikey.
All electronics are contained in one of two NEMA4x enclosures: one box is for high voltage and the other for low voltage. The high voltage box contains the solid state relays, a 24v power supply, and the pump relays.The low voltage box contains
the Arduino and all the other circuits.The brewery has its own breaker panel.