[Stoves] Wendlelbo's : Re Large TLUD --- TLUD Stove history

[rongretlarson at comcast.net]

AD (cc list) 

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. 
. 
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. 

Ron 

----- Original Message -----
From: "Anand Karve" <adkarve at gmail.com> 
To: "Discussion of biomass cooking stoves" <stoves at lists.bioenergylists.org> 
Sent: Sunday, August 28, 2011 9:37:22 PM 
Subject: Re: [Stoves] Wendlelbo's : Re Large TLUD --- TLUD Stove history 

Dear Stovers, 
if you have a very simple stove with a grate at the base of the 
firebox, you can eliminate almost all the smoke. The air coming 
through the grate is the primary air and the air entering the firebox 
through the fire mouth (the opening through which the wood sticks are 
inserted) is the secondary air. The primary air causes the wood to 
burn and the secondary air enters the flames to burn the volatiles. By 
playing around with this simple configuration, we have designed a 
stove that has become quite popular in the area where we operate. TLUD 
works in a similar manner, but it suffers from the disadvantage that 
one cannot add or reduce the fuel quantity, which is possible in our 
stove. Rajan had some time ago reported a similar configuration, but 
he made the system unnecessarily complicated by having the primary air 
coming into the firebox through a tube. A simple grate is good enough. 
Yours 
A.D.Karve 

On Mon, Aug 29, 2011 at 12:03 AM, Crispin Pemberton-Pigott 
<crispinpigott at gmail.com> wrote: 
> Dear Paul 
> 
>>...Those stoves only got that TLUD name in 2005, and were first named 
> "Top-Lit UpDraft" in 2004 in the Anderson-Reed document at the LAMNET 
> conference - found at the Stoves 
> website). From 1985 to 2005 Reed called the technology IDD, for 
> Inverted DownDraft.) 
> 
> I am sure you are also aware that the natural draft TLUD method was being 
> promoted at the municipal government level as the traditional smoke limiting 
> method for the standard highveld mbaula quite some time ago. 
> http://www.erc.uct.ac.za/jesa/volume17/17-2jesa-wentzel2.pdf 
> 
> I have no idea how far back the technique goes, but it was called 'lighting 
> it like grandma does' which gives you a hint. 
> 
> I have attached a picture of an mbaula being lit using the technique, 
> including the draft inducing upper pipe which both speeds the fire's 
> development but also reduces smoke dramatically. It accomplishes the same 
> things as adding a fan underneath with the added advantage of pulling air 
> into the secondary air holes - something more difficult to achieve with a 
> fan. 
> 
> The grate is about half-way up the lower can and the coal is on top. When 
> the flaming pyrolysis is completed the top 'pipe' is removed. Tests by Vinny 
> and James at the SeTAR Centre show about an 85-90% reduction in PM2.5. 
> 
> Maybe John Davies knows how long ago this style of TLUD ignition (and 
> cooking) was used. As it is also called the 'Scotch method' it is likely to 
> go back to England in the 1700's and was imported during the emigration boom 
> post-1886. 
> 
> I have a colour photo of Fig 3 from Marlett's paper linked above if anyone 
> want to see the fire more clearly. 
> 
> Regards 
> Crispin 
> 
> 
> _______________________________________________ 
> Stoves mailing list 
> 
> to Send a Message to the list, use the email address 
> stoves at lists.bioenergylists.org 
> 
> to UNSUBSCRIBE or Change your List Settings use the web page 
> http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org 
> 
> for more Biomass Cooking Stoves, News and Information see our web site: 
> http://www.bioenergylists.org/ 
> 
> 
> 



-- 
*** 
Dr. A.D. Karve 
President, Appropriate Rural Technology Institute (ARTI) 

*Please change my email address in your records to: adkarve at gmail.com * 

_______________________________________________ 
Stoves mailing list 

to Send a Message to the list, use the email address 
stoves at lists.bioenergylists.org 

to UNSUBSCRIBE or Change your List Settings use the web page 
http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org 

for more Biomass Cooking Stoves, News and Information see our web site: 
http://www.bioenergylists.org/ 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20110829/1878d969/attachment.html>