For agitation I use an electric motor which sits in a custom fabricated mounting base over the side of and on the top of each tank. Each motor turns a custom designed & fabricated polypropylene propeller shaft and propeller. Via the use of different size pulleys one can speed up or slow down the agitation at will. In my case, I am using 3 speed motors that were removed from Electrolux mixmasters (though I only use the fasted speed at all times). They’re strong, quiet, thermally protected and with the proper squirrel cage cooling fans (from a vacuum cleaner repair shop), they run 24/7. With regards to the Coleman coolers, I simply use aquarium air pumps as a source of agitation and even heating. The motors are operated with a Programmable Logic Controller (PLC). Though this is not the only intended use for the PLC as I intend on controlling the heaters digitally and an overhead crane (not in place yet). For now, the PLC operates only the agitation motors (mostly because I’m lazy).
The motor turning the propeller shaft with the squirrel cage cooling fan underneath.
The mounting bracket I made to hold the motors.
