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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 Kirk<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'>At 1:25 of the video there is some separation of the flames on the right indicating the fire is right on the edge of having too much air and too little gas – maybe cold air from above. I presume this is at the lowest power setting.<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'>Following this the central flames comes up with a lot of PM in it (bright yellow). This seems to indicate that there is a shortage of secondary air and an excess of gas in the centre. It looks as if the addition of more primary air may have weakened the draft available for the secondary air. This is solvable. <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'>How about dropping into the space where the flame is, a tube that reduces the diameter? The space is really empty of flame. There doesn’t seem to be any advantage to that. <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'>Something else to check is: lower the pot rest height so there is no possibility of air entering from the top into the upper chamber. When filming with the pot off, the combustion is strongly affected by the absence of the pot. It is hard to say for sure but it looks around the 2 minute mark that there air entering from the top in a downward running tube and then scooping the outside of the flame near the secondary air holes, the pushing it up again without much mixing into the gas core. Putting on the pot (but with much lower stands) might change what is happening inside the chamber. <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'>The flame coverage is very good at low power – full deck of flame, but that doesn’t last when it is turned up. The secondary air can’t reach the centre either because of lack of pressure, holes are too many and small, or the venturi is not doing what you want. You might be ahead to put some downward angled holes running into the gas below the venturi. What you have works well (tending to the edge of stability as mentioned above) at that power level. It is possible that the flame instability is entirely caused by the cold air coming from above. Try putting a perforated metal plate over the top so you can see through, the gas can get out, but air can’t get in.<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'>Like this:<o:p></o:p></span></p><p class=MsoNormal><img width=378 height=332 id="Picture_x0020_1" src="cid:image001.jpg@01D1015E.BB52BB90"><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'><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'>If you want to get the effect of a chimney, akin to what I was doing, the secondary air should be added under the bottom if it will go in there. It has more chance to mix on the way up. <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 will send you a video of the effect pot on/pot off directly to your address.<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'>Regards<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'>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'><o:p> </o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Kirk,<br><br>Nice work!!!! Kevin Adair is doing some venturi additions also. <br><br>Paul<br><br><o:p></o:p></p><pre>Doc / Dr TLUD / Prof. Paul S. Anderson, PhD <o:p></o:p></pre><pre>Email: <a href="mailto:psanders@ilstu.edu">psanders@ilstu.edu</a> <o:p></o:p></pre><pre>Skype: paultlud Phone: +1-309-452-7072<o:p></o:p></pre><pre>Website: <a href="http://www.drtlud.com">www.drtlud.com</a><o:p></o:p></pre><div><p class=MsoNormal>On 10/7/2015 5:09 PM, kgharris wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial",sans-serif'>Roberto,</span><o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial",sans-serif'>Nice. I would like to see test results for particulates. It should be very clean. It looks like it is loosely based on Crispins flame tube design with holes added in the tube where the Venturi low pressure area is. The holes are at the bottom of the burner, so there is better draft and a good burning area above. If I understand correctly Crispin is using the tube differently, to concentrate the heat and increase the dwell time for the flame in that hot environment. His secondary air is all added before the flame tube. Your design looks more compact and perhaps would be a better choice for a TLUD. </span><o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial",sans-serif'>There is a limit to how much gas the burner can handle. When the foil is removed and more primary air is added the burner is overloaded with gas and a tall diffusion flame forms. I have been trying to handle this problem by adding more mixing capability, and have had some improvment, but further work is needed. The problem with the mixing tubes I am using is that along the edges of the combustor, the air exiting the tubes exits at an angle instead of straight out. This holds the gasses below the burner along the edges, and adds to blowing them to the center, overloading the center of the mixer and wasting air at the edges of the combustor. This would not be a problem with your design. You might be able to use two or three of theses mixers side by side to gain a clean higher fire power. </span><o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial",sans-serif'>The concentrator ring is intended to mix the wood gas and air, and the Venturi mixer is intended to mix the wood gas and the air, so you have a duplicate mixing system. I am not saying good or bad, just something I notice. </span><o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial",sans-serif'>I see Julian has expressed some doubts about the Venturi concept. Good for him. I would be very happy if someone with adiquate equipment and technical ability proved or disproved the TLUD Venturi concept, either way. I perhaps will have to bite the bullet and buy a manometer with the ability to measure down to .001 inch of water column. My rather primative home made manometer did show a slight pressure drop at the mixer, but not enough to get any measurments. Our local college science department didn't seem to be interested.</span><o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial",sans-serif'>Attached are some photos of the primary control valve I am currently using very successfully. It looks like something similar might work for you.</span><o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial",sans-serif'>Good work Roberto, </span><o:p></o:p></p></div><div><p class=MsoNormal> <o:p></o:p></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial",sans-serif'>Kirk</span><o:p></o:p></p></div><blockquote style='border:none;border-left:solid black 1.5pt;padding:0cm 0cm 0cm 4.0pt;margin-left:3.75pt;margin-top:5.0pt;margin-right:0cm;margin-bottom:5.0pt'><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial",sans-serif'>----- Original Message ----- <o:p></o:p></span></p></div><div><p class=MsoNormal style='background:#E4E4E4'><b><span style='font-size:10.0pt;font-family:"Arial",sans-serif'>From:</span></b><span style='font-size:10.0pt;font-family:"Arial",sans-serif'> <a href="mailto:roberto.poehlmann@gmail.com" title="roberto.poehlmann@gmail.com">Roberto Poehlmann</a> <o:p></o:p></span></p></div><div><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial",sans-serif'>To:</span></b><span style='font-size:10.0pt;font-family:"Arial",sans-serif'> <a href="mailto:stoves@lists.bioenergylists.org">stoves@lists.bioenergylists.org</a> <o:p></o:p></span></p></div><div><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial",sans-serif'>Sent:</span></b><span style='font-size:10.0pt;font-family:"Arial",sans-serif'> Tuesday, October 06, 2015 5:53 PM<o:p></o:p></span></p></div><div><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial",sans-serif'>Subject:</span></b><span style='font-size:10.0pt;font-family:"Arial",sans-serif'> [Stoves] TLUD pellets stove with a venturi burner.<o:p></o:p></span></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><div><p class=MsoNormal>Hi,<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>This is a video of one of my prototypes of a TLUD pellet stove.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>The difference with a "normal" TLUD burner, is that it has a 3 inch tube with secondary air holes after the concentrator ring.<o:p></o:p></p></div><div><p class=MsoNormal>On top of the the tube, i put a cone to expand the path of the gases, to shorten the flame, and to have a little internal chimney for draft.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>One advantage of this burner, is that you can also burn all of the charcoal made at the pyrolysis stage, with a nice secondary blue flame (if you wish) .<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><a href="https://youtu.be/uXMeGcZEYX0">https://youtu.be/uXMeGcZEYX0</a><o:p></o:p></p></div><p class=MsoNormal><br clear=all><o:p></o:p></p><div><div><p class=MsoNormal>Greetings<br>Roberto Poehlmann<o:p></o:p></p></div></div><div><p class=MsoNormal>Valdivia, Chile.<o:p></o:p></p></div></div><div class=MsoNormal align=center style='text-align:center'><hr size=3 width="100%" align=center></div><p class=MsoNormal><o:p> </o:p></p></blockquote></blockquote><p class=MsoNormal><o:p> </o:p></p></div></body></html>