If you've ever turned over a compost heap, then you'll know what a stinky, dirty job it is. Now, imagine doing it for hours at a time, on a much larger scale. That's what Austrian scientists have envisioned, designing an autonomous compost turner as a result.
Throughout the world, many municipalities and agricultural businesses compost their organic waste in large yards. In order to keep that waste mixed and rotting evenly, tractor-drawn machinery is typically used to turn it over on a regular basis. The drivers of those slow-moving tractors are continuously subjected not only to unpleasant odors, but also to heat and gases given off by the decaying matter.
Seeking an alternative, a team at the Graz University of Technology is developing a self-driving vehicle to do the job.
Measuring 4 meters wide by 2.5 meters long (13.1 by 8.2 ft), the battery-electric caterpillar-tracked device is guided by a combination of GPS, stereo camera data, accelerometers, sensors on the wheels within its treads, and a 3D model of the composting yard. These not only allow it to track its location within the yard, but they also keep it centered as it travels back and forth along the parallel rows of compost – most yards already arrange their compost in such rows, for easier handling.
A toothed roller, not unlike the cylindrical beater brush on a vacuum cleaner, does the actual compost-turning.
The technology is currently being commercialized by Austrian company Pusch & Schinnerl, which partnered with the university on the development process. Known as the eWender, the vehicle could enter production sometime next year.
It can be seen in action, in the video below.
Source: TU Graz
I have. It isn't.
It can be hard work. The benefits of this innovation are surely for dealing with industrial scale compost (dealing with green waste) rather than to avoid something icky.
[Compost isn't the same as manure, at least in the UK.]
It needs to be covered (old tarps or carpets do it), and air able to be drawn in at the bottom (I use an old bit of pipe) and have a vent-hole open at the top. An oven temp probe in the top vent will show about 60° after one day of building, and 72°C has been seen. You could cook a slow-food roast in one! At all stages the composting material smells ok, and the end product is beautiful dark brown crumbly rich soil, good enough to eat, almost. You can compare it to the bouquet of a very good red.
If your lot smells, you should be putting your material into a sealed container, and letting it convert minus oxygen - that's what smells. That process makes hydrogen sulphide and methane. In a sealed container after a year it’ll reduce to an intensely rich brown smell-less liquid, which when diluted make an remarkable fertiliser.
A search engine is your friend.