even with this 30% moisture fuel, the restriction in the hearth is staying at 850-930c on a 3kwe load. this corresponds to 1200c or so at the nozzles most likely (but unmeasured). these are the temps we want to see for full tar conversion. we had a white filter and unmolested sawdust after our first runs yesterday.
the chipped fuel we’re running looks like this. we’re also using it in the bottom of the filter, as you can see here. the rest of the filter is filled with rice husk and sawdust.
today we’re going to experiment with chipped bamboo, rice straw, and rice husk. the bamboo i expect will work ok. the straw and rice husk much less so. but it should be interesting learning.
the big issue with the rick husk is the over 20% silica content. at high temps this forms silicon dioxide, or crystobalite, which is a bad nasty. the particular dynamics of its formation and deformation, as well as the nature of its health issues, i have not got caught up on. i am not clear if our high temp tar conversion strategy is going to create silicon dioxide problems. as i’m internet challenged locally, if someone(s) could go figure out the dynamics of its formation, and summarize the issues here, it would be highly helpful.