<div dir="ltr"><div>Hi Jock;</div><div><br></div><div>Thanks for your comment "Tweak one [design parameter] and you tweak them all". The interactions in ND-TLUDs are interesting. We don't see them so much in FD-TLUDs because the fan overrides all. I developed the burner I am using with prototype tin-can TLUDs and found that the gasification rate was higher over the whole power curve with moderately large secondary air holes. The size of the air holes can't be too large, however, because as they become larger they structure the air jets less and less, and you also end up with big gaps between the holes. I have found that round holes are better than rectangular holes, because the round holes are better at self-regulating the flow of secondary air as the flame size changes.</div><div><br></div><div>Geometry and placement of secondary air holes can affect the distribution of burner draft between primary and secondary air. Paul Anderson made an interesting comment to me the other day. He wondered if as the size of the gas flame increased, the flame became more fuel rich. Perhaps he will elaborate on this for us.</div><div><br></div><div>The burner I am using is simple and robust. There are, of course, other approaches to burners, as you and Kirk Harris have shown.</div><div><br></div><div><br></div><div>All the best,</div><div>Julien.</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Dec 12, 2014 at 8:19 AM, Jock Gill <span dir="ltr"><<a href="mailto:jock@jockgill.com" target="_blank">jock@jockgill.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="auto"><div>Julien,</div><div><br></div><div>If you increase draft you will increase the "pull" on both secondary air and primary. This should allow you to reduce the size, amount, of the primary air holes.</div><div><br></div><div>If you increase the amount of secondary air you will reduce the amount of primary air. It is easier to pull in secondary air than primary. The draft, primary and secondary air are all tightly coupled in a non linear system. It might be linear if the resistance in the fuel bed were a constant, but as the fuel is pyrolized the resistance is constantly changing. And of course the variable amount of heat as the process progresses also contributes to the non linearity of the system.</div><div><br></div><div>Tweak one and you tweak them all.</div><div><br></div><div>Cheers,</div><div><br></div><div>Jock </div><div><br><div><div style="font-family:UICTFontTextStyleBody">Jock Gill</div><div style="font-family:UICTFontTextStyleBody">P. O. Box 3</div><div style="font-family:UICTFontTextStyleBody">Peacham, VT 05862</div></div><div style="font-family:UICTFontTextStyleBody"><br></div><div><a style="font-weight:bold;background-color:rgba(255,255,255,0)" href="https://plus.google.com/_/notifications/emlink?emr=02164940119180120523&emid=CIn6jOiavboCFcgLTAodARYAAA&path=%2F102260924343967128597%2Fop%2Fu&dt=1383089746165&ub=50" target="_blank"><font color="#000000">google.com/+JockGill</font></a></div><div><br></div>Extract CO2 from the atmosphere!</div><div><div class="h5"><div><br>On Dec 11, 2014, at 7:20 PM, Julien Winter <<a href="mailto:winter.julien@gmail.com" target="_blank">winter.julien@gmail.com</a>> wrote:<br><br></div><blockquote type="cite"><div><div dir="ltr"><div>Hi All;</div><div><br></div><div>Attached is an "experimental vignette". It is a report on a small experiment conducted to get a better understanding of natural draft TLUD design.</div><div><br></div><div>The height of the riser above a gas burner was doubled. The resulting increase in draft in the burner resulted in faster gasification rates and higher temperatures in the TLUD. Besides riser height, I have found that a number of design elements of the gas burner can increase gasification rate such as the size of secondary air holes.</div><div><br></div><div>I have a few more of these experimental vignette to come, such as how creating a vortex flame may not be a good idea, and how heat is lost from the side walls of the reactor, and a reasonable heap on reactor temperature for different fuels. Now that snow is on the ground in Southern Ontario, I have more time to analyze data.</div><div><br></div><div>All the best</div><div>Julien<br clear="all"><br>-- <br></div><div><div dir="ltr">Julien Winter<br>Cobourg, ON, CANADA<br></div></div>
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</div></blockquote></div></div><blockquote type="cite"><div><Height of gas burner riser.pdf></div></blockquote><blockquote type="cite"><div><span>_______________________________________________</span><br><span>Stoves mailing list</span><br><span></span><br><span>to Send a Message to the list, use the email address</span><br><span><a href="mailto:stoves@lists.bioenergylists.org" target="_blank">stoves@lists.bioenergylists.org</a></span><br><span></span><br><span>to UNSUBSCRIBE or Change your List Settings use the web page</span><br><span><a href="http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org" target="_blank">http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org</a></span><br><span></span><br><span>for more Biomass Cooking Stoves, News and Information see our web site:</span><br><span><a href="http://stoves.bioenergylists.org/" target="_blank">http://stoves.bioenergylists.org/</a></span><br><span></span><br></div></blockquote></div></blockquote></div><br><br clear="all"><br>-- <br><div class="gmail_signature"><div dir="ltr">Julien Winter<br>Cobourg, ON, CANADA<br></div></div>
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