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</o:shapelayout></xml><![endif]--></head><body lang=EN-CA link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Dear Marc<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>></span>That cutaway is beautiful! Great example of "let the product speak for itself"<o:p></o:p></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>That shows the importance of having a plasma cutter handy.</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Since seeing counterflow in action, I understand exactly what you're describing with the air flows. <o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>Good. A picture is worth 100 descriptions.</span><o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>></span>I didn't understand your emphasis on keeping the flame near the bed with a "descending burner" until this paragraph:<o:p></o:p></p><div><blockquote style='margin-left:30.0pt;margin-right:0mm'><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;background:white'>>></span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;background:white'>The secondary air is send across the surface to keep a deck of flame going at the height of the holes. This obviates the need for adding a circular disk at the top to ’keep the flame going’. Adding a ‘concentrator’ as Paul calls it takes more material and moves the fire too far away from the heat of the pyrolysis bed leading to unwanted flame-outs from time to time. </span><o:p></o:p></p></div></blockquote><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>Well, try building a couple of pyrolysers and see how they go. There is a good reason gasifier buildings are always standing by with a box of matches to toss into their latest smoke bomb.</span><br clear=all><o:p></o:p></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#1F497D'>></span>What's on the "to-do" list for this class of design, Crispin? Are you looking to push it into other applications? Apply the principles to improve existing design? (like you mentioned with advancing the Anglo SupraNova)<span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The application of the combustion method is potentially widespread. I think it solves a lot of problems that otherwise require tinkering by the cook (which they hate). The Anglo SupraNova incorporates the secondary air control rather easily because it is not a conventionally shaped charcoal burning chamber. It can be improved further, I believe. We are just ‘trying-it-out’ with a dozen or so to see what the populace thinks about it. The lighting cone is being introduced at the same time so there is a double-whammy.<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The stove GERES is presently teaching people how to build is very similar to the Anglo Supra and can be modified to the same benefit. The advantage of the metal+clay body is that the clay can break and it still stays together (which is why a Jiko has the same arrangement). This is not a very forward-thinking approach however. If the clay is properly constituted and the firing correctly done, there should be no need for a metal body, unless that portion is re-useable in future. The metal is expensive.<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>We will of course be sharing the developments of the Anglo/LS/Thai Bucket stove with anyone who is interested. Cecil Cook and I will try to work with GERES and the WB to create a regional product development collaborating group, possible through the S4Group which concentrates on local initiatives and local experts. I believe the whole stove can be made from clay for under $1 and I will try that in March to see if thermal expansion of the inner shell breaks the outer shell. I expect a fully developed clay version to out-perform a metal Vesto.<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>There is a guy in Maputo who (illegally) copies the Vesto using a clay body with a clay air tube and a metal combustion chamber. It is very efficient. The outer wall never gets warm. It is a great charcoal stove (which is the dominant fuel).<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Regards<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Crispin<o:p></o:p></span></p></div></div></div></div></div></body></html>