[Stoves] more TLUDs in history

Sun Aug 28 21:51:26 CDT 2011

Dear Cripsin, Paal, Paul and stovers

Paal is clearly one of most important forefathers of modern improved cookstoves for he is one of the first (as noted by Paul) to apply formal experimentation to stove development. 

Crispin is also right in noting that Top Lit Updraft technology has been around for a long time. There evidence that middle Pleistocene hominids used top lit fires in pits for smokeless heat and cooking, as it is also the case in Greece during the Upper Paleolithic period. 

As far as concentrator lids, also known as orifice plates or restrictors, they are commonplace in combustion and fluid dynamic studies.  In large versions, FAO in the sixties used them in some of their improved charcoal kilns designs, and in stoves, they have been used for many decades (if not centuries). Notable examples are Giese's protable biomass cookstove in 1959 or Nottingham's precursor to the Gaia (former electrolux) alcohol stove from 1921.

What makes Paal's earlier and continued efforts so significant is he, like Reed and Larson and Crispin, make stove improvements following scientific principles rather than trial and error thereby accelerating and refining the current state of the art in ways that have helped many.

Here's to Paal and others following his good examples. 

Nat of WorldStove

stoves at lists.bioenergylists.org

Message: 2
Date: Sun, 28 Aug 2011 20:06:18 -0500
From: "Paul S. Anderson" <psanders at ilstu.edu>
To: Discussion of biomass cooking stoves
    <stoves at lists.bioenergylists.org>,  Crispin Pemberton-Pigott
    <crispinpigott at gmail.com>
Subject: [Stoves] South African "TLUDs" with coal ---- TLUD Stove
    history
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    <20110828200618.19075abu1c6k22o0 at redbirdmail.illinoisstate.edu>
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Dear Crispin, and to all interested in the history of TLUDs (and in  
dissemination efforts),

Thank you for finding and providing (as an attachment in his previous  
message) the informative article "Granny shows the way..." published  
in the refereed Journal of Energy in Southern Africa, May 2006, an  
article that was first submitted to the editors in August 2004.  I had  
never seen it before.  Imagine what else might be out there, yet to be  
discovered.

I hope that someone can provide more documentation about ?the old  
?Scotch-fire? lighting method? mentioned on page 18.

I always try to give credit to those who deserve it, and there is much  
merit in that article by Wentzel.   Many people should read it.

However, concerning the historical record about TLUDs, apart from the  
Scotch-fire reference that still needs clarification, I find nothing  
in the article that could possibly change the history of the TLUD  
fires as currently presented.  The article discusses the BNM method,  
which translates into ?to make fire like Granny.?

1.  The BNM method refers to burning coal (and references to biomass  
are almost negligible), and there is minimal reference to fires of the  
size for cooking.  The South African embuela or mbuela or mbawuala   
(it has several different spellings) is a coal burner that is mainly  
used to heat houses in the cold season in the impoverished townships.   
It is responsible for massive outdoor air pollution and many deaths  
from CO poisoning indoors.

2.  Granny Mashinini learned of the stove when it was first introduced  
into South Africa near the town of Secunda (which is where John Davies  
lives), as reported in a 1999 publication, which I do not yet have,  
but it implies that its introduction only a few years earlier.  That  
does not match well with Crispin?s statement about it being ?quite  
some time ago.?  Granny M. added a nice touch (a couple handfuls of  
coal on top of the starter materials on top of the column of coal) to  
help get the fire started better.  That is probably more than 10 years  
after Tom Reed had his moment of inspiration about what is now known  
as TLUD.  Her picture on page 20 shows her to be a rather young  
grandmother, so I will guess that she was under 30 when Tom Reed and  
Paal Wendelbo were doing their most important work.  Therefore, I  
reject Crispin?s intimation that the method is old when he wrote:

> I have no idea how far back the technique goes, but it was called 'lighting
> it like grandma does' which gives you a hint.

3.  The manuscript was submitted for publication in August 2004.    
Prior to that time, significant publications and on-line  
communications and even presentations were public knowledge about the  
lighting of biomass on the top (later to be called TLUD).  Although  
the pioneer work of Wendelbo did not re-surface until 2008, Reed?s  
early publication in 1996 about his innovation is widely known and  
referenced.  John Davies and I separately but at the same conferences  
(at least two events) presented discussions and conducted live-fire  
demonstrations in South Africa prior to the end of 2003 (which is the  
last time I was in South Africa).  And John was top-igniting COAL in a  
small gasifier.  And I presented about such activities at early  
meetings of ETHOS in Seattle.  With that as the background, why do the  
References in the article have no mention of the prior work about top  
lighting for clean combustion?   This is a peer-reviewed document, so  
it is not just the author who overlooked the prior art.

4.  The amount of information about the South African initiatives to  
disseminate the BNM method is well worth reading to help us understand  
efforts to introduce and inform about innovations with solid-fuel  
combustion devices.  They spent millions on demonstrations that  
reached over 15,000 households in South Africa.  And all indications  
are about success.  I hope that someone in South Africa can up-date us  
on the progress to have these top-lit updraft coal burners adopted  
throughout the country.

In summary, ANOTHER SUCCESS STORY for TLUDs!!!  And it is almost all  
in the 21st century.

Paul S. Anderson, PhD
Known to some as:  Dr. TLUD    Doc    Professor
Phone (USA): 309-452-7072   SKYPE: paultlud   Email: psanders at ilstu.edu
www.gtz.de/de/dokumente/giz2011-en-micro-gasification.pdf   (Best ref.)

Quoting Crispin Pemberton-Pigott <crispinpigott at gmail.com>:

> 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
>
>

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