Brian, You want a higher gas velocity to sweep the ash through the system, but the bigger issue to me is just keeping the solid fuel flowing which requires a larger volume in the oxidization zone until the particle size burns down and can flow through the restriction.
Stephen -----Original Message----- From: Brian D Paasch <[email protected]> To: Discussion of biomass pyrolysis and gasification <[email protected]> Sent: Mon, Aug 9, 2010 2:54 pm Subject: [Gasification] Imbert chemistry question Hi all, Got a question about Imbert style downdrafts…. One of the obvious haracteristics of an Imbert style gasifier is the hearth restriction. The ombustion/oxidation zone is physically larger than the subsequent harcoal/reduction zone. As best I can find in the literature, the size change s worked out so that there is an approximate four-fold increase in superficial as velocity through the reduction zone versus the oxidation zone. The actual elocity increase is even higher due to the higher temp of the reduction zone ver the oxidation zone and also to an increase of total mass as the asification of the solid fuel adds its molecular load to the gas stream. So my question is, why? Why did the engineers of the Imbert decide that they eeded a higher gas velocity through the reduction zone versus the oxidation one? Thanks! -brian ______________________________________________ asification mailing list [email protected] ttp://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org ttp://gasifiers.bioenergylists.org ttp://info.bioenergylists.org _______________________________________________ Gasification mailing list [email protected] http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org http://gasifiers.bioenergylists.org http://info.bioenergylists.org
