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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;mso-fareast-language:EN-US'>Dear Todd<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='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>In this photo it appears there is a drop-down hood or door that closes off the excess primary air that would normally enter through the fuel hole.<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='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><a href="http://www.silverfire.us/page_10_1/silverfire-survivor">http://www.silverfire.us/page_10_1/silverfire-survivor</a><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='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>Is there some side wall or baffle that assists this?<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='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>Do you provide secondary air through other holes inside the stove? It is mentioned but not shown.<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='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>Have you measured the typical excess air level above the combustion chamber for a typical test?<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='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>I am interested in knowing how you calculated the thermal efficiency. You mean the fire-heat to pot-heat transfer efficiency, right?<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='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>Thanks<br>Crispin<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='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>+++++++</span><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>Subject: Cajun Rocket Pot / TLUD Soot<o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Soot is an end product on all pots used on biomass stoves with or without fins or skirts. Heat transfer is increased by adding more surface area to cooking pots with dowels, finned ribs, corrugated ribs, rows of fins or full skirted pots as discussed. Steel woks with lamented cast iron bases with fins have been available in China for quite sometime. We have both in our SilverFire showroom. They are designed specifically for biomass. Finned pots specific for LPG have also been available for a number of years.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> The Chinese Enron turbo pots have been marketed in the USA for several years (<a href="http://www.turbopot.com">www.turbopot.com</a>). Rebates for Enron finned pots are available from utility companies in the USA for LPG savings. <span style='font-family:"Verdana","sans-serif";color:#262626'> </span>The LPG fin design on Turbo pots differ significantly from the biomass design. Narrow LPG finned pot channels clog with soot and the end result is that the soot negates heat transfer, if used with biomass. Fin designs for biomass cooking are significantly wider and work well. Time to boil is significantly reduced.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> The ease of cleaning and product acceptance is also important, as Dale touched upon. We had early prototypes of both fin pot & skirted pots fabricated in 2008. I was not a proponent of the Aprovecho fin pot. It made no sense for the end user. The early design had fins that extended from the base and up the sidewalls of the pot. We would have had to provide tetanus shots for end users, had that design ever reached the market. The exterior design was unacceptable. Cleaning or handling the pot was a handling hazard. <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> Our production pot we introduced to the introduced to the market was the skirted pot. It cut approximately 5 minutes to time to boil in our early WBT work. I brought the skirted pot to market though, for the important fact that we designed the skirt to protrude below the cast iron cook top. This important design feature reduced the chance of the pot sliding off the stove to prevent burning the cook or children. Since soot did not accumulate on the exterior skirt, it also meant less cleaning for the cook, compared to the finned pot. The skirted pot was more acceptable than our fin pot design. Combining a skirt and fins would provide even greater heat transfer. A well-designed pot must be easy to clean. <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> Todd Albi, SilverFire <o:p></o:p></p></div></div></div></body></html>