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</o:shapelayout></xml><![endif]--></head><body bgcolor=white 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;mso-fareast-language:EN-US'>Dear Paul<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>></span>The metal-pipe version you described could have some practical implications for use with biomass as well as coal. <span style='color:#1F497D'><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'>Correct – it can burn anything. It will do best with a particle size that is 1/10<sup>th</sup> of the diameter.<o:p></o:p></span></p><p class=MsoNormal><br>We will assume that scrap pipe is available and cheap.<br><br><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>In Asian countries district heating pipes are widely available in various conditions from the scrapyards. There are many miles of it in Ulaanbaatar, for example.<o:p></o:p></span></p><p class=MsoNormal><br>Pipe will withstand the corrosion well.<span style='color:#1F497D'><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'>They tend to be 4-10mm thick. They can take a lot of heat for a long time.</span><br><br>Pipe of such dimensions will be emptied / cleaned at a door on the side near the bottom (or with a trap-door through the bottom which would be more involved and require legs/supports.) There would be no allowance for tipping over to dump out char or ash.<br><br><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>There is a grate 100 mm above the bottom with 7mm gaps. IT is loose and can be lifted using a wire hook pushed through the ash. When it is lifted it dumps everything on the grate (which might include stones) into the bottom space. There is an air control door on the bottom though which the ash can be scooped using a hooked plate.<o:p></o:p></span></p><p class=MsoNormal><br>The empty unit will stay hot/ warm for quite a while, so it probably should not be reloaded and reignited as a TLUD / MPF unit right away. (We lack experience about this.)<span style='color:#1F497D'><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'>This has proven, in Ulaanbaatar, not to be a problem, even with very hot ceramic linings (this stove mas no lining). Refuelling the hot stove and relighting on top showed no tendency to over-evaporate volatiles even using very high volatile fuel. It is just not an issue. Coal is cold and quickly cools everything down. It is possible that pellets would be an issue, but that would depend on the moisture content so it could work some of the time.<o:p></o:p></span></p><p class=MsoNormal><br>After a TLUD operation with MPF (migratory pyrolytic front), the fire will be at the bottom. The unit COULD be continuously feed additional fuel from the top, opperating as a traditional updraft gasifier. <span style='color:#1F497D'><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'>I was able to successfully add coke from previous burns, as described before.<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>Note that this would be bottom burning like an incinerator, which generally causes worse emissions unless additional adjustments are made. <span style='color:#1F497D'><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'>Not the case. It was just fine. Nothing was changed. Remember that fuel size is important as it functions somewhat like a packed bed gasifier.<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>The entry points and amounts of air (primary and secondary) can greatly impact this performance. For some societies and situations, this might be appropriate.<br><br><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>The secondary air was fixed and would probably be adjusted with the fuel composition, however that said, the fuel was at least sub-bituminous to bituminous coal and it did not smoke at all after the wood was well lit. Once the pyrolysis is complete, there is no chance of smoke. All coal stoves burn very cleanly at some point. The problem is adding fuel on top of an existing fire which if avoided can dispense with PM emissions almost entirely. Certainly 99%.<o:p></o:p></span></p><p class=MsoNormal><br>REQUEST:<br>Who has conditions to do the development work about this type of device? NOT a tinsmith's job!!! Please volunteer. Or make a request for some minor financial assistance. <br><br><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>In theory it could be done with an angle grinder, hammer and drill – not even welding. It depends how simple you want to go. Most places have arc welding.<o:p></o:p></span></p><p class=MsoNormal><br>Remember that this can have significant usefulness in colder climates where room heating is also of value.<span style='color:#1F497D'><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'>Water heating is surprisingly important as a fuel consumer. I have just seen that at least as much fuel is used for heating water as heating the home. Dedicated water heaters are under-discussed.<o:p></o:p></span></p><p class=MsoNormal><br>Crispin's time in Tajikistan is limited. We need some continuity. Maybe a team effort. We can start by bringing together the various messages about this, including Crispin's photos. <span style='color:#1F497D'><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'>I left TJ and went to Kyrgyzstan for a week and returned to Canada already. Drawings will be available soon for all these stoves. In places where only dung is available there might be some interest in the “bricked stove” approach. It is easy, cheap and lasts a long time.<o:p></o:p></span></p><p class=MsoNormal><br>I will participate, but I do not work alone any more. Make yourself known!!!<br><br><span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Thank you, this is important work. We have a continent to transform.<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'>Crispin<o:p></o:p></span></p><p class=MsoNormal> <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>