<html><head><style type='text/css'>p { margin: 0; }</style></head><body><div style='font-family: Arial; font-size: 12pt; color: #000000'>Crispin etal (couldn't get to "Alexis")<br><br> 1. I had a small off-list exchange a few days ago with Andrew H. who also thought (on this list) that Paul Olivier had obtained a pre-mixed flame. The exchange went this way, with my talking to Andrew: <br><br>
<span style="font-style: italic;">" Below you describe Paul's flame as premixed. Unless something has
changed (Paul?), I believe the flamelets are of the diffusion type -
all secondary air is above the "Belonio burner"..</span>"<br style="font-style: italic;">
<br>Paul responded a few days ago.<br><br><em>"Ron, you are right. </em><br style="font-style: italic;"><span style="font-style: italic;">Air comes into contact with the gas only after it exits the burner holes.</span><br style="font-style: italic;"><span style="font-style: italic;">Air does not come into contact with gas before it exits the burner holes.</span><br style="font-style: italic;"><span style="font-style: italic;">
Paul</span>"<br style="font-style: italic;"><br>2. It now seems critical to better understand everything about the secondary air flow, which obviously is different from Belonio's. Paul responded a few days ago on this - but I didn't follow his answer. This is to request a bit more from Paul - since that detail <span style="font-weight: bold; text-decoration: underline;">MAY</span> have been the cause of the halving of boil-time. (I can think of several other causes.) I am interested in the gap dimensions - that are probably in the drawings sent to his machine shop. I probably could find these in the "stoves" archives, but am sure it will be easier for Paul to repeat that construction detail - and to affirm that the tests were with exactly this and wth no other changes.. <br> But I also hope Paul can make a more direct comparison new test between his and the earlier Belonio boil-time data. Paul, is that new test possible for you?<br> Thanks in advance.<br><br>Ron<br><br><hr id="zwchr"><b>From: </b>"Crispin Pemberton-Pigott" <crispinpigott@gmail.com><br><b>To: </b>"Discussion of biomass cooking stoves" <stoves@lists.bioenergylists.org>, "Paul Olivier" <paul.olivier@esrla.com><br><b>Cc: </b>zong@ilstu.edu, "Belonio - Philippines" <atbelonio@yahoo.com>, "Corey Berman" <bizurman@gmail.com>, "Hugh McLaughlin" <wastemin1@verizon.net>, "Bob Fairchild" <solarbobky@yahoo.com>, 'Alexis', "Chua He" <chuazh@gmail.com><br><b>Sent: </b>Friday, March 16, 2012 10:56:09 AM<br><b>Subject: </b>Re: [Stoves] Belonio burner top on TLUD stoves was Re: radiant heat capture, total heat measurement<br><br>Dear Paul A<br><br>I think quite a bit more experimentation is needed before copying the top<br>end of Alexis' burner. The evolution is that it was not a premixed flame and<br>the structure was built with that in mind. The change to a premixed flame<br>was not matched by a change in the structure. The result is that there is a<br>very high excess air rate passing through the underside and emerging by the<br>pot. This has the effect of heating a lot of air an lowering the gas<br>temperature beside the pot.<br><br>I feel that a 30% improvement in heat transfer efficiency can be achieved by<br>addressing this issue.<br><br>I have noticed that stove builders fall roughly into two groups: those who<br>build high neat transfer efficiency stove bodies but with mediocre<br>combustion, and those who make really good combustion but neglect the detail<br>of getting good heat transfer. In some cases there is a sort of blind<br>adherence to the idea that a fuel is 'clean' and there is no need for<br>either. 'Clean burning means efficient,' which is nonsense.<br><br>We should all be paying a lot of attention to both aspects of stove<br>building: efficient combustion and efficient heat transfer. One does not<br>automatically derive from the other.<br><br>Regards<br>Crispin<br><br><br>-----Original Message-----<br>From: stoves-bounces@lists.bioenergylists.org<br>[mailto:stoves-bounces@lists.bioenergylists.org] On Behalf Of Paul S.<br>Anderson<br>Sent: Friday, March 16, 2012 6:07 PM<br>To: Discussion of biomass cooking stoves; Paul Olivier<br>Cc: zong@ilstu.edu; Belonio - Philippines; Corey Berman; Hugh McLaughlin;<br>Bob Fairchild; Alexis; Chua He<br>Subject: [Stoves] Belonio burner top on TLUD stoves was Re: radiant heat<br>capture, total heat measurement<br><br>Dear all,<br><br>Paul Olivier commented: (full message is still below, with link to a<br>photo)<br><br>> ..... which has always led me to wonder why the Belonio burner hole <br>> pattern was not adopted on natural draft units.<br>> If a burner housing were added, I think the unit I experimented with <br>> would work much better.<br><br>Paul O. raises an excellent point. I think that the moderate complexity of<br>the Belonio hole pattern and secondary air inlet (contrasted to simple<br>concentrator hole) has kept me and probably most others from experimenting<br>with it. Perhaps we incorrectly associated it too much with the forced air<br>(Fan Assisted = FA) aspects of Belonio's rice husk gasifiers.<br><br>Very little is known about the tops of TLUDs except that some amount of<br>constriction is needed to force the mixing of air and gases.<br><br>I hope that the engineers (such as Bob Fairchild and student<br>engineers) and others who are now working on TLUD stove issues will<br>seriously consider the Belonio top and related enhancers of combustion of<br>the gases.<br><br>Paul (Paul A.; not to be confused with Paul O.)<br>--<br>Paul S. Anderson, PhD<br>Known to some as: Dr TLUD Doc Professor<br>Phone (USA): 309-452-7072 SKYPE: paultlud Email: psanders@ilstu.edu<br>www.gtz.de/de/dokumente/giz2011-en-micro-gasification.pdf (excellent ref.)<br>My website specific for TLUD information: www.drtlud.com = www.DrTLUD.com<br><br><br>Quoting Paul Olivier <paul.olivier@esrla.com>:<br><br>> Kevin,<br>><br>> You say:<br>> *# OK!! A 50% reduction in boiling time is very significant.<br>> What can you now tell us that will enable us to apply it to other stoves<br>> and combustion conditions?*<br>><br>> I once did an experiment in which I made the 150 Belonio about half its<br>> original height.<br>> I then filled it with chunks of wood and put a Belonio burner on top.<br>> This was a natural draft unit without a fan.<br>> This is what it looked like:<br><br>> http://dl.dropbox.com/u/22013094/150%20Burner/Image2097.jpg<br><br>> But looking back on this, I see that there were so many problems with this<br>> burner,<br>> even aside from the fact that it had no burner housing.<br>><br>> You raise an interesting question, though, which has always led me to<br>wonder<br>> why the Belonio burner hole pattern was not adopted on natural draft<br>units.<br>> If a burner housing were added, I think the unit I experimented with would<br>> work much better.<br>> The central problem that I see with a natural draft unit is an uneven<br>> upward flow of primary air.<br>> At times too much CO2 is created, and some burner holes lose their flames.<br>> Also I would imagine that the inlet of primary air has to be strictly<br>> control to get a consistent outlet of gas at the burner.<br>><br>> A natural draft TLUD is very complicated,<br>> and I truly marvel at those who get them to work on such a broad variety<br>> of fuels.<br>><br>> Thanks.<br>> Paul<br>><br>> Thanks.<br>> Paul<br><br><br>----------------------------------------------------------------<br>This message was sent using Illinois State University RedbirdMail<br><br><br><br>_______________________________________________<br>Stoves mailing list<br><br>to Send a Message to the list, use the email address<br>stoves@lists.bioenergylists.org<br><br>to UNSUBSCRIBE or Change your List Settings use the web page<br>http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists<br>.org<br><br>for more Biomass Cooking Stoves, News and Information see our web site:<br>http://www.bioenergylists.org/<br><br><br>_______________________________________________<br>Stoves mailing list<br><br>to Send a Message to the list, use the email address<br>stoves@lists.bioenergylists.org<br><br>to UNSUBSCRIBE or Change your List Settings use the web page<br>http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org<br><br>for more Biomass Cooking Stoves, News and Information see our web site:<br>http://www.bioenergylists.org/<br><br></div></body></html>