<div dir="ltr">Dear Paul,<div><br></div><div>You may have noticed that the TLUD featured in Jim's talk yesterday did not do so well. I hope that the TLUD community can help to tune up TLUDs so quality stays high.</div>
<div><br></div><div>There are bad Rockets and good ones. The devil is in the details, as they say. More bad ones than good ones, unfortunately.</div><div><br></div><div>As Crispin points out, there are also good and bad stoves that use forced air. </div>
<div><br></div><div>I think we need design principles for TLUDs so folks can know how to make high performance TLUDs but we're not there yet as far as I know. </div><div><br></div><div>All Best,</div><div><br></div><div>
Dean</div><div class="gmail_extra"><br><br><div class="gmail_quote">On Thu, Aug 29, 2013 at 6:35 PM, Paul Anderson <span dir="ltr"><<a href="mailto:psanders@ilstu.edu" target="_blank">psanders@ilstu.edu</a>></span> wrote:<br>
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<div>Stovers, (and sent to my
<a href="http://www.drtlud.com" target="_blank">www.drtlud.com</a> Webmaster who can place this on my website, but
comments will be answered via the Stoves Listserv.)<br>
<br>
On 8/28/2013 10:56 PM, Dean Still wrote:<br>
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<div dir="ltr">......<br>
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<div>Jim Jetter reports that a TLUD can have fewer fine
particles compared to fan stoves. We're finding the same
thing.</div>
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It is time to get serious about how TLUD stoves have superior
performance. Finally we are getting lab testing data. Well, not
really. We are getting "statements" but the data sets are not
being presented to us. That is okay. We can wait for Dean and
Jim and ALL OTHER STOVE TESTING CENTERS to provide some data.
Let's just use the above statement as the basis for my comments
here.<br>
<br>
1. "Fan stoves" is a BAD name. Any stove with a fan can be a "fan
stove". What Jim and Dean are discussing are stoves that include
Oorja, Biolite (two models?), Philips, Reed Woodgas Campstove, maybe
some units from China. At least THREE different combustion regimes
are included in the above named stoves. But Who knows which ones
they are talking about? THEY know, but protocols etc are
preventing the data results from being given, even with or without
the names of which stoves. But we do know that they have fans.
But so do some other stoves.<br>
<br>
2. "Stoves with fans" is also not sufficiently specific, but at
least they could be recognized for what they are, which is, stoves
of different types that have fans. <br>
<br>
A. They could be "Rocket stoves with fans" as in the Biolite Home
stove and maybe something (prototypes perhaps?) from Envirofit or
Stove Tec.<br>
<br>
B. They could be "Fan-jet stoves with fans" (or some other name,
but this is what I have called them for several years). These are
stoves with intense, forceful mixing of air deep into the fuel
chamber. These include the Biolite Campstove, Philips stove, the
WorldStove Lucia-FA (forced air), and the Turbococina of El
Salvador. These are (perhaps) related to pellet-stoves as sold in
North America in which the intensity of the jets of air consume
small quantities of pellet fuels in a small cup-type combustion
chamber. For sure these are NOT TLUD stoves. They can well be
micro-gasifier stoves. They can certainly be highly regarded.
But they are not the only stoves with fans. And to call them "fan
stoves" is unclear and unfair to the other types of stoves that can
have fans. <br>
<br>
C. They could be "Simple Improved Cookstoves - ICS - with fans".
Something like a bucket-stove with a fan blowing onto the flaming
fuel. No examples come to mind, but add a fan and have a "fan
stove." <br>
<br>
D. They could be "TLUD stoves with fans". Yes, TLUD stoves can be
operated with fans. The opening statement is referring to natural
draft TLUD-ND having less PM than TLUD-FA. TLUD-FA stoves
include the Reed Woodgas Campstove, the Oorja stove, the
Belonio/Olivier rice husk gasifiers, McLaughlin's Joy-to-the-World,
and my 2004 prototype "Juntos B" (which is described in the 2004
paper "Biomass Gasification: Clean Residential Stoves, Commercial
Power Generation, and Global Impacts (available at
<a href="http://www.drtlud.com/resources/publications-and-multimedia/psa-catalogue/" target="_blank">http://www.drtlud.com/resources/publications-and-multimedia/psa-catalogue/</a>
). And there are probably other TLUD-FA units.<br>
<br>
3. So, one study that needs to be done is to compare the PM from
TLUD-ND and TLUD-FA. Do such results already exist? Do we need
to wait very long for these results? I ask these questions to
those who have the capabilities and the financial resources to
conduct those tests. You know who you are. Ongoing budgets and
some major grants have been given for capabilities to conduct these
types of tests. And it is not just EPA and Aprovecho who get such
funding. But some grants prevent the dissemination of results
until much later.<br>
<br>
4. BUT. Yes, there is a BIG BUT to be considered. This is
because TLUD-FA (those with fans) have been blatantly mis-used and
the test results could be erroneous because the test was not stopped
when the TLUD pyrolysis process stopped, which is when the bottom
burning of char started and continued as long as operators were
feeding in raw fuel at the top. <br>
<br>
I repeat: the TLUD testing needs to be <u><i>stopped when the TLUD
pyrolysis process stopped, which is when the bottom burning of
char started and continued as long as operators were feeding in
raw fuel at the top. </i></u><br>
<br>
[[ I have already prepared a short document about this and will
post it soon. ]]<br>
<br>
In conclusion, let's get our understanding clear that the addition
of a fan to a stove does NOT automatically put that stove into the
Tier 3 and Tier 4 categories of low PM emissions. FIRST think of
what kind of combustion the stove utilizes: simple ICS, Rocket,
TLUD, other micro-gasification, other .... THEN consider if it
has a fan in it. <br>
<br>
In biology, first the animal type, and then if it flies or not:
Birds fly (but not all of them); Many insects fly; some
pre-historic reptiles could fly; and some mammals (bats) can
fly. Flying is important, but Phyla is more important. Fans are
important, but not more important than the combustion regime.<br>
<br>
STATEMENT: I believe that the TLUD stoves (whether ND or FA) are
cleaner about PM than the other combustion regimes because the
process of pyrolysis leaves the inert materials (non-combustibles
known as ash) held tightly to the charcoal that is created. So, do
NOT burn the charcoal. Especially do not burn it with vigorous
streams of air at the level of the charcoal. [And there are
probably additional variables to be studied.]<br>
<br>
This hypothesis remains to be proven. But while we wait for the
test results, money will be channeled to other stove technologies,
field tests of health will be conducted withOUT having a TLUD stove
included in the study, and people will continue to suffer (and some
will die) because of the high PM levels in household cookstoves. It
is late 2013 and studies of TLUD stoves are only scratching the
surface of what things need to be studied.<br>
<br>
Oh well, better this progress than less progress. And all of the
TLUD enthusiasts are certainly willing and eager to join into any
and all efforts.<br>
<br>
Paul<br>
<pre cols="72">Paul S. Anderson, PhD aka "Dr TLUD"
Email: <a href="mailto:psanders@ilstu.edu" target="_blank">psanders@ilstu.edu</a> Skype: paultlud Phone: <a href="tel:%2B1-309-452-7072" value="+13094527072" target="_blank">+1-309-452-7072</a>
Website: <a href="http://www.drtlud.com" target="_blank">www.drtlud.com</a></pre>
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