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</o:shapelayout></xml><![endif]--></head><body lang=EN-CA link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Dear Xavier<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>How’s things, man?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Please have a look at the combustion chamber on the bottom right of slide 8 in Christa’s presentation at ETHOS this year: <a href="http://www.vrac.iastate.edu/ethos/files/ethos2012/SunPM/Roth_GIZ%20charcoal%20work.pdf">http://www.vrac.iastate.edu/ethos/files/ethos2012/SunPM/Roth_GIZ%20charcoal%20work.pdf</a> <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I was thinking it is probably worth combining the POCA-style grate into the Improved Malgache you made in Benin though I’d have to think about where the secondary air would be injected. The layout of the Malgache with preheating certainly lines up well with POCA grate’s basic design (also seen on the Pulamusa and Mama-musa).<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>If the preheating entered just above the lip of the chamber holding the charcoal, the door below could be a two stage opening – one for lighting (large hole, simple closer) and another small one for primary air control. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>The original POCA (MCS) had separately controlled primary and secondary air but the way it went to market dropped that. In principle it would be best to have both, but controlling the burn rate by choking primary air is better than a JIKO-like door that turns it into a CO-bomb.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>What do you think? It would work best with your last round version of the Improved Malgache, with a primary air supply to the ‘fuel holding bowl’ then the preheated secondary air entering between the two cones pouring in horizontally right at the bottom of the upper cone, driving the fire into a pointed cone as described a day ago.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>There is very little additional material required and it would produce a big drop in CO because the primary burn could be controlled. It also gives a large draft for the primary air. When closed, it would settle into a low flow mostly secondary supply.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Do you want to share a picture of the round Improved Malgache from Benin?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks<o:p></o:p></p><p class=MsoNormal>Crispin thinking of Zambia and Madagascar<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>