Mixers used in mobile aquaculture experiment
Vince Cate contacted Cliff Goudey, Director, Offshore Aquaculture Engineering Center, Massachusetts Institute of Technology, Sea Grant College Program. Cliff used some slow speed mixers to make a self propelled aquaculture cage which was tested near Puerto Rico. These mixers can produce thrust of 3.4 kN/760 lbs from power input of 4.6 kW/6.2 hp. With two of these mounted in fixed positions he was able to control the 62 foot diameter cage like a normal twin screwed boat at 0.5 to 0.6 knots. He said the propeller and motor were around $20,000 each. He used a Toshiba Model VFS11-2037PME variable frequency motor controllers which cost about $1,600 each.
These 8 foot diameter propellers are off the shelf equipment used for very efficient mixing in the waste-water treatment industry.