My thoughts are that this Is probably what the local producer is already doing-and has been for years, in response to the demands of their own local markets. Richard Stanley
Sent from my iPhone On Dec 28, 2010, at 8:18 AM, "Crispin Pemberton-Pigott" <[email protected]> wrote: > Dear Richard and Andrew > > I know we all quote the 6 kg of air for burning biomass please keep in mind > that to get an excess air ratio of about 100% it takes twice as much as 'it > seems'. > > With the gasifiers, the ratio between primary and secondary might be a 1:6 > split, but the secondary needs to provide all the excess air as well so it > is more like 1:10 than 1:6, yes? > > The primary side for the gasifiers needs to remain the same (which is based > on experience, really) but the theoretical need for air on the secondary > side is surely less than the real need? > > So when it comes to the air moving through the hollow briquette, can we > treat the whole needed air supply as being present 100% (instead of a > separate secondary supply) and concentrate only on mixing and combustion > chamber temperature? It looks as if the hole is a means to sneak the whole > air supply past the light biomass fuel without increasing the burn rate > which is what happens in most ordinary fires. I think Paul made this point > clear when we were talking about getting secondary air through the coal bed > earlier in '10. > > So, one big advantage of using hollow briquettes is that it is probably > possible to get the whole air supply through in one go and avoid having the > complexity of secondary admission. > > This being the case, it should be possible to create a perfect hole size for > each briquette mix and compression/forming method. This means in practice > that for any consistent product, one should vary the hole diameter and test > them in a stove, measuring the excess air. A simple method to do that is to > look for visible smoke most of the time. That means the air supply is > inadequate. > > On the briquette press side, it means having replaceable cores with many > diameters. Fully implemented, one could select briquettes with the > appropriate burn rate: denser probably needing smaller cores to have the > right air supply to burn slower and longer. > > Got thoughts on this? > > Regards > Crispin NOT in the snowstorm > > > _______________________________________________ > 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 _______________________________________________ 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
