<html><head><style type='text/css'>p { margin: 0; }</style></head><body><div style='font-family: Arial; font-size: 12pt; color: #000000'>AD (cc list)<br><br> It seems to me you have described below a rocket stove. Don't most of them have a lower grate? The advantage you give of being able to operate in a continuous rather than batch manner is certainly real. But I think that advantage is negated by higher emissions and by a need to tend the fire more continually and no chance to set the primary air and forget the stove for a long time. Turn down ratios are meaningless in a rocket stove and I think your description - or am I missing something? (I suspect a good bit of secondary air is also coming through the grate.<br>. <br> I am responding next to Richard Stanley on the use of briquettes - where he talks of removing completely charred briquettes upon completion of the pyrolysis phase for use in soils. I think that is unlikely in your (rocket?) design. Or are you also describing something that can produce char - which is of course my prime interest. And char-making can drive the cost of stove operation negative.<br><br>Ron<br><br><hr id="zwchr"><b>From: </b>"Anand Karve" <adkarve@gmail.com><br><b>To: </b>"Discussion of biomass cooking stoves" <stoves@lists.bioenergylists.org><br><b>Sent: </b>Sunday, August 28, 2011 9:37:22 PM<br><b>Subject: </b>Re: [Stoves] Wendlelbo's : Re Large TLUD --- TLUD Stove history<br><br>Dear Stovers,<br>if you have a very simple stove with a grate at the base of the<br>firebox, you can eliminate almost all the smoke. The air coming<br>through the grate is the primary air and the air entering the firebox<br>through the fire mouth (the opening through which the wood sticks are<br>inserted) is the secondary air. The primary air causes the wood to<br>burn and the secondary air enters the flames to burn the volatiles. By<br>playing around with this simple configuration, we have designed a<br>stove that has become quite popular in the area where we operate. TLUD<br>works in a similar manner, but it suffers from the disadvantage that<br>one cannot add or reduce the fuel quantity, which is possible in our<br>stove. Rajan had some time ago reported a similar configuration, but<br>he made the system unnecessarily complicated by having the primary air<br>coming into the firebox through a tube. A simple grate is good enough.<br>Yours<br>A.D.Karve<br><br>On Mon, Aug 29, 2011 at 12:03 AM, Crispin Pemberton-Pigott<br><crispinpigott@gmail.com> wrote:<br>> Dear Paul<br>><br>>>...Those stoves only got that TLUD name in 2005, and were first named<br>> "Top-Lit UpDraft" in 2004 in the Anderson-Reed document at the LAMNET<br>> conference - found at the Stoves<br>> website). From 1985 to 2005 Reed called the technology IDD, for<br>> Inverted DownDraft.)<br>><br>> I am sure you are also aware that the natural draft TLUD method was being<br>> promoted at the municipal government level as the traditional smoke limiting<br>> method for the standard highveld mbaula quite some time ago.<br>> http://www.erc.uct.ac.za/jesa/volume17/17-2jesa-wentzel2.pdf<br>><br>> I have no idea how far back the technique goes, but it was called 'lighting<br>> it like grandma does' which gives you a hint.<br>><br>> I have attached a picture of an mbaula being lit using the technique,<br>> including the draft inducing upper pipe which both speeds the fire's<br>> development but also reduces smoke dramatically. It accomplishes the same<br>> things as adding a fan underneath with the added advantage of pulling air<br>> into the secondary air holes - something more difficult to achieve with a<br>> fan.<br>><br>> The grate is about half-way up the lower can and the coal is on top. When<br>> the flaming pyrolysis is completed the top 'pipe' is removed. Tests by Vinny<br>> and James at the SeTAR Centre show about an 85-90% reduction in PM2.5.<br>><br>> Maybe John Davies knows how long ago this style of TLUD ignition (and<br>> cooking) was used. As it is also called the 'Scotch method' it is likely to<br>> go back to England in the 1700's and was imported during the emigration boom<br>> post-1886.<br>><br>> I have a colour photo of Fig 3 from Marlett's paper linked above if anyone<br>> want to see the fire more clearly.<br>><br>> Regards<br>> Crispin<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>><br>><br><br><br><br>-- <br>***<br>Dr. A.D. Karve<br>President, Appropriate Rural Technology Institute (ARTI)<br><br>*Please change my email address in your records to: adkarve@gmail.com *<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>