Dear Richard I certainly like the idea of shaping the load of sawdust to create anything approaching a constant burn. The main reason for the failure of sawdust burning stoves to become popular (so I am told) is because the firs starts off small and gets larger and larger with time until it is a raging inferno with a huge surface area. Choking it creates massive smoke.
So addressing that is perhaps the main issue. Briquetting is the simplest obvious approach. I note that Dedza Pottery uses sawdust to file their kilns, dropping it into a 'centrifugal fan-like' impeller, falling into a blast of air from a real centrifugal fan. Certainly that qualifies as a fluidized bed but it is pretty miserable to operate (continuous attention needed, with a stick in hand). How about a downward-angled cone that tapers larger towards the bottom dropping loose sawdust into a primary air choked region under the combustion chamber? The Mayon Turbo Stove pretty much does that using a donut of fuel but it is tapered the other way and manually rattled to feed episodically. I like Larry's angled 'steps' for larger fires. It raises in my mind the relationship between the particle size and the distance across the feeder. 6 times? 10 times? 20 times? Which will work without clogging? Regards Crispin enjoying Christa's book of micro-gasifiers and fuels... _______________________________________________ Stoves mailing list to Send a Message to the list, use the email address Stoves mailing list to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org for more Biomass Cooking Stoves, News and Information see our web site: http://www.bioenergylists.org/ [email protected] http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org
