In my last post, I showed a picture of a wood powered water heater, so we’ll roll up our sleeves and get into how this was designed. But first a warning! Boiling water is easy to do, boiling water in a closed container and not blowing yourself up is much trickier, in fact I’ve heard it said that there is the equivalent of a stick of dynamite in 500 grams of boiling water ! So if you blow yourself up be it on your own head . Having said that I have spent a fair bit of time creating a design that is simple to build, safe and efficient.
The first post on the rocket oven left many with more questions than they started with so this is a follow up to cover some aspects in more detail. It would probably help to re read the first article and my replies to comments as I’m just going to forge ahead with more detail on the design.
On my first design I was prepared, even expecting to have to modify things to get it to work properly. One fundamental question I had was how small the rocket oven cross section could be and still do the job.
During our last workshop at the Koanga Institute, we built a rocket stove. Our design brief was very specific in that the stove had to be practical, easy to use and long lasting, whereas what is being built by most backyard experimenters like myself, while being fun to make and muck around with, are more along the lines of “camp stoves” built from tin cans that quickly disintegrate with use. Another consideration which I felt was important was that most rocket stoves are just that – stoves, as in – place a pot on top and boil something.
Biochar is organic matter that is burned slowly, with a restricted flow of oxygen, and then the fire is stopped when the material reaches the charcoal stage. Unlike tiny tidbits of ash, coarse lumps of charcoal are full of crevices and holes which help them serve as life rafts to soil micro-organisms. Biochar alone added to poor soil has little benefit to plants, but when used in combination with compost and organic fertilisers, it can dramatically improve plant growth while helping retain nutrients in the soil…read more!
Is biochar a fertilizer? The answer, oddly, is no.by David Yarrow…read more!
It seemed obvious to me that I needed to go far further with utilising humanure than I had previously (we always had a composting toilet, but it was emptied into the orchard) – after all most of the minerals we eat go straight through us, except if we are actively growing (i.e. children)…read more!
So where does the “appropriate” in Appropriate Technology come from? To me, it is technology that “fits” well into a place or setting. No further enlightened? Okay, I’ll make some generalizations and go from there. For the “technology part,” I like W. Brian Arthur’s definition whereby technology is the capture or use of a phenomena for a specific purpose. So this could be everything from construction of a compost pile, (consciously promoting the action of bacteria to break down organic matter for whatever reason) to a system of community governance.