<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>David,</div><div><br></div><div>A few notes inserted below.<br><br><div><div style="font-family: UICTFontTextStyleBody; -webkit-text-size-adjust: auto;">Jock Gill</div><div style="font-family: UICTFontTextStyleBody; -webkit-text-size-adjust: auto;">P. O. Box 3</div><div style="font-family: UICTFontTextStyleBody; -webkit-text-size-adjust: auto;">Peacham, VT 05862</div></div><div style="font-family: UICTFontTextStyleBody; -webkit-text-size-adjust: auto;"><br></div><div><a href="https://plus.google.com/_/notifications/emlink?emr=02164940119180120523&emid=CIn6jOiavboCFcgLTAodARYAAA&path=%2F102260924343967128597%2Fop%2Fu&dt=1383089746165&ub=50" style="font-weight: bold; background-color: rgba(255, 255, 255, 0);"><font color="#000000">google.com/+JockGill</font></a></div><div><br></div>Extract CO2 from the atmosphere!</div><div><br>On Apr 4, 2014, at 12:20 PM, David Young <<a href="mailto:dyoung@pobox.com">dyoung@pobox.com</a>> wrote:<br><br></div><blockquote type="cite"><div><span>On Thu, Mar 27, 2014 at 12:16:31PM -0400, Jock Gill wrote:</span><br><blockquote type="cite"><span>I really hope others will try this FXJ burner design and see what it</span><br></blockquote><blockquote type="cite"><span>can do for them. Have any of you seen a burner like this before?</span><br></blockquote><span></span><br><span>Jock,</span><br><span></span><br><span>You have inspired me to try a gas wick.</span><br><span></span><br><span>In the FXJ burner, I'm not sure that I understand how the shape and</span><br><span>materials in the I-shaped member made of washers and copper pipe affect</span><br><span>the burn, but this is my working theory: the lower washer concentrates</span><br><span>the wood gas and secondary air into a smaller area and increases the</span><br><span>speed of their ascent. The lower washer may also act as a bluff body,</span><br><span>adding some turbulence: as the gases pass the lower washer, the opening</span><br><span>up of the combustion chamber will cause eddies to form on top of the</span><br><span>washer. The eddies will help to mix the air with the fuel. The copper</span><br><span>pipe confines the combustion somewhat. The top washer concentrates the</span><br><span>flame & hot air on your pot for better heat transfer.</span><br></div></blockquote><div><br></div>About right. It looks to me as if makes more sense to force the gases to the secondary air rather than away from it.<div><br></div><div>As Crispin observes, flamelets allow for better results than flames. Flames suggest sub optimal fuel/air mixing and proportions.</div><div><br></div><div>The copper pipe acts a reflector of the secondary air jets. This increases mixing. </div><div><br></div><div>The well defined combustion chamber also increases residence time. The gases simply can not jump up and out of the stack. </div><div><br><blockquote type="cite"><div><span></span><br><span>Does that make any physical sense? Is it what you were going for?</span><br><span></span><br><span>I decided that my old burner deserved another try, so I have put aside</span><br><span>the burner made of 18-ounce beverage cans.</span><br><span></span><br><span>I added some more primary air holes to the old burner. I added a third</span><br><span>row of 1/8-inch secondary air holes, and I widened the top two rows to</span><br><span>3/16 inches. With these changes, I got more blue flame than before,</span><br><span>long yellow tips, less red-orange flame licking the top of chimney with</span><br><span>or without a pot installed. That is without the gas wick.</span><br><span></span><br><span>I tried to create some turbulence by putting a fan-shaped insert at the</span><br><span>bottom of the primary air can, like the Vesto stove does, but I could</span><br><span>not tell you for certain that that made a difference. Sometimes the</span><br><span>flames swirled slightly. That is also without the gas wick.</span><br><span></span><br><span>Last night I left out the fan-shaped insert. I inserted a "gas wick"</span><br><span>made from a small (10-ounce?) tomato-paste can. The bottom of the wick</span><br><span>is at the level of the bottom row of secondary-air holes, and the top</span><br><span>extends into the chimney by a few inches. I saw a similar effect as</span><br><span>Jock did with his new design: short blue flames, short yellow tips, much</span><br><span>less flame crawling up the chimney. Some flame did crawl up the wick,</span><br><span>but only on one side of the burner.</span><br><span></span><br><span>I was able to start the burner with the wick in place, wood gas</span><br><span>generation began, but the flame went out after a while. I was able to</span><br><span>restart the wood gas after I removed the chimney and the wick. I let</span><br><span>the stove burn for a while, and then I gradually lowered the wick into</span><br><span>the flames and pressed it into place. Then I reinstalled the chimney.</span><br><span></span><br><span>I have a couple of guesses about what was going on with the wick last</span><br><span>night. First, the wick is too cold at start, and it quenches the</span><br><span>flames. </span></div></blockquote><div><br></div><div>I expect it is because the 'wick' reduces on the draft on the primary air. The hotter the top of fuel load the stronger the draft draft.</div><div><br></div><div>In general, there has to be a strong enough primary air/draft combination to sustain the startup phase of pyrolysis. Once established, my systems tend to take 10 to 12 minutes to do this, you are off to the races. </div><br><blockquote type="cite"><div><span>I should probably raise the wick. Second, the burner is very</span><br><span>sensitive to the wick position: it has to be centered and level or else</span><br><span>it doesn't shape the flames properly and they will be high on one side.</span><br><span>I need a better scheme for suspending the wick in the proper alignment.</span><br><span></span><br></div></blockquote><div><br></div><div>I suggest you try your wick with top and bottom plates as I do with FXJ burner. Pls let me know your results.</div><div><br></div><div>Thanks,</div><div><br></div><div>Jock</div><br><blockquote type="cite"><div><span>I have attached a top view of the blue flame. Some 1/8-inch steel rod</span><br><span>steadies the gas wick in the chimney. It is glowing red hot!</span><br><span></span><br><span>Dave</span><br><span></span><br><span>-- </span><br><span>David Young</span><br><span><a href="mailto:dyoung@pobox.com">dyoung@pobox.com</a> Urbana, IL (217) 721-9981</span><br></div></blockquote><blockquote type="cite"><div><firstblue.jpg></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">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">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/">http://stoves.bioenergylists.org/</a></span><br><span></span><br></div></blockquote></div></body></html>