John Parnum
Job role:Retired Engineer and Inventor
Skills:Engineering, electronics, robotics, prototyping
I am a retired Mechanical Engineer with a big interest in electronics controlling mechanical things. I create my machines using wood, aluminium, plastic, DC motors, batteries, servos, sensors & Arduinos. They are designed to be not too big so I can take them into schools as a STEM Ambassador to engage & enthuse children. My Lego Sorting Machine, Wheelie Bin Waste Robot, Local Delivery Robot, and Dinosaurs Automata have all proved popular with years 4, 5 and 6. I believe passionately in increasing STEM awareness in primary schools.
Recent blog entries
I have enjoyed making the Toilet Turbine and it is not far from being finished. I am not using a turbine but have a system designed to deal with everything which might be flushed down a toilet (and that is the challenge).
There is a plastic bin (as a tank) and flush unit mounted on a wooden stand. There is a diverter which can sent the fluids to either bucket. Once one bucket is full it is released to drop down and empty. The empty bucket is raised up, the diverter turned ready to fill that bucket. The orange string will be used to rotate a generator I am waiting on. Obviously I am using clean water and in reality there would be a toilet in between the flush and the generating system.
My Version 2 solution has a turbo wheel mounted on ball bearings (to make it free turning) with 8 empty baked bean tins to catch the waste. Although all testing has been done using clean water, the system is designed to be capable of dealing with all types of waste.
The turbo wheel turns quite slowly so I needed to speed up the generator shaft using some gears. A voltmeter connected to the generator shows the voltage being generated as it turns. There was much testing to get everything working. It has probably taken 40 hours of perseverance.
The wonderful idea from Joey to make electricity from sewage raises a number of challenges. The most important is dealing with what is flushed down a toilet. Not only human waste but also lots of other things, so the turbine has to be able to deal with everything! Clearly filters will not work as they will need constant cleaning.
My first idea was to put the waste into two buckets attached to a string. These would alternately move up and down with the generator attached to the pulleys. The water is supplied by a plastic box supported on a wooden structure and controlled by a standard toilet flush. My Version 1 bucket system worked but then I had a better idea!
