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</o:shapelayout></xml><![endif]--></head><body bgcolor=white lang=EN-CA link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span style='color:#1F497D'>Dear Paul<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>></span>Please confirm: Something like a bucket with holes in the bottom. <span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Yes.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal>No upper extension. <span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Added during ignition. Removed once coked. Behaviour varies.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal>No attempt to have a TLUD-type concentrator or directed horizontal entrance of the secondary air. <span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>That is not special to TLUD’s. Upper holes serve as horizontal air entrances.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal>Just light one at the bottom (bottom burning only - BB) and the other at the top (meaning that the pyrolytic front will be moving downward through the stack of fuel, as migratory pyrolytic front MPF until it reaches the bottom.) <br><br><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>The two approaches are used. Top lit is advertised as ‘improved’ but it goes back a long way. The top lit version does not mean an MPF. You can only really get an MPF if it is a packed bed gasifier and virtually no one is doing that.<o:p></o:p></span></p><p class=MsoNormal><br>2. So the fuel-bed temperatures were always measured in the bottom of the BB unit, but were measured at the position of the MPF as the MPF progressed downward. Right? If not, please describe.<br><br><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Don’t know.<o:p></o:p></span></p><p class=MsoNormal><br>3. How did the experimenters control (make hotter or less hot) the fuel bed temperatures? <span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Don’t know. I don’t think they did.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal>4. How deep is the pile of coal fuel?<span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Typical is < 150mm.</span><br><br>5. Please describe the "secondary" burning. Flames flickering on the top? tall, short, etc.<br><br><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Tall in the beginning and short after pyrolysis.<o:p></o:p></span></p><p class=MsoNormal><br>6. And which way (BB or MPF) is the common practice in South Africa?<br><br><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Bottom lit updraft (BLUD) is common, and TLUD is also common. MPF is not going to be seen, not a real one. That would require complete air control and there is no attempt to do that in an mbaula.</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman",serif;color:#1F497D;mso-fareast-language:EN-CA'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-CA'>Regards<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-CA'>Crispin<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-CA'><o:p> </o:p></span></p></div></body></html>