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Crispin. See below.<br>
<pre class="moz-signature" cols="72">Doc / Dr TLUD / Prof. Paul S. Anderson, PhD
Email: <a class="moz-txt-link-abbreviated" href="mailto:psanders@ilstu.edu">psanders@ilstu.edu</a>
Skype: paultlud Phone: +1-309-452-7072
Website: <a class="moz-txt-link-abbreviated" href="http://www.drtlud.com">www.drtlud.com</a></pre>
<div class="moz-cite-prefix">On 9/29/2017 11:33 PM, Crispin
Pemberton-Pigott wrote:<br>
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Dear Paul</div>
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Again I feel you are imposing restrictions on how products
should work. Recycled char can definitely be burned. If you have
pellets that yield 15-20"% of initial fuel mass then definitely
some of the char burned. That establishes the principle that
TLUDýs can burn char. <br>
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No. The char yield is associated with some char combustion during
the time of the pyrolysis, but that is not the same as having the
char as the input fuel.<br>
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The stoves that recycle char to the next cooking session burn a
large amount of the total char such that the mass 'carried
forward' is about the same eaých time. This establishes that the
total char produced, net, each replication is completely
combusted. <br>
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That is "burning char" during the pyrolysis process, not the burning
of char as the input fuel (100% of the input being charcoal).<br>
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All that is needed is to increase the gasification rate until
there is significant char gasification. ýThis does not hold for
all models nor all fire powers. Some produce more than they can
recycle so a portion is lost, or retained for other purposes. In
the fuel consumption calculation that is fuel fed, meaning more
is needed next time. For example a stove may produce 20% char
from a mix that was 90% fresh pellets and 10% old char. In that
case half the remaining char is not used next time. <br>
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Tom Reed showed years ago that the amount of char produced is
inversely impacted by the amount of primary air. Expect that to be
the case.<br>
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Stoves that do this have been made and sold in Indonesia for
several years. <br>
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Please send details about those stoves, numbers, how they are used,
photos, videos, etc.. I do not dispute that statement. But it
would be nice to have some supportive info so we all can interpret
what you says you have (measured or seen or been told or believe).<br>
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While there is a 'purist' group holding that char is produced
and not burned, <br>
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I said above that some char is burned during the pyrolysis stage.
TLUD processes have OXIC pyrolysis (oxygen present, but in limited
amount), also called "flaming pyrolysis", but I prefer the term
"glowing pyrolysis." So some char will be consumed. ANOXIC
pyrolysis (no entrance of oxygen) is what occurs in a retort.
Expect some char to be consumed during the pyrolysis <br>
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background-color:rgb(255,255,255)">and there are stoves like
that, it is not a general case. It is particular to those
products with a low temperature gas production rate. The
cleanest stove we tested was like that. The most efficient was
like the case above, in the high 30's, assessed on the Central
Java cooking sequence. <br>
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Efficient. As in heat transfer efficiency, I assume. And what you
describe is logical. that is, turn up the heat (more primary air)
and the stronger fire moves the hot gases better and that improves
the efficiency.<br>
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The Rocketworks stove from South is in the same efficiency
range. It is a stick burnerý with a novel grate and both
preheated secondary and tertiary air, i.e. not a gasifier nor
semi-gasifier. <br>
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I am not familier yet with that stove. Interesting. Do you have
a definition for "tertiary air?" Please let us know.<br>
<br>
Crispin, referring to your initial sentence, I do not IMPOSE
restrictions on TLUD usage. I point out (to the best of my
ability) what I believe (know in some cases) to be true and the best
practices. But just suggestions. I have seen so many different
methods and materials and designs about TLUD stoves for over 16
years. SOMETIMES THERE ARE SOME REAL GOOD INNOVATIONS (witness
Kirk Harris and Alexis Belonio). I try to call attention to the
innovations that seem to have strong merit.<br>
<br>
And sometimes the differences are (be nice, use soft words) less
than stellar. Some people totally disregard what is clearly
established. Maybe they do not read the materials. Or maybe the
"not invented here" complex takes over. Or they like reinventing
the wheel. They are welcome to do all of that and more. (But
not with my time nor with my funding.)<br>
<br>
To me, the burning of charcoal as charcoal (not during the migratory
pyrolytic front stage) inside a TLUD stove is to be avoided.
Reasons include:<br>
a. overheats the metal, shortening the life of the fuel chamber,<br>
b. The air enters at the bottom, and the char is burning there, and
it is underneath the layers of relatively cooler char (that looks
black, not glowing), which blocks the radient heat from reaching the
pot,, and <br>
c. the hot char at the bottom is relatively far away from the
bottom of the pot (and everyone knows that proper charcoal stoves
have the pot very close to the hot char.)<br>
<br>
In baseball, "three stricks and you're out." But this isn't
baseball, and I am not the umpire. But the ballgame is more fun if
the players learn good techniques so that they have better chances
to hit the ball (or cook the meal). But I would rather have many
people playing ball with suboptimal skills (or using TLUD stoves in
less than optimal ways) than to not have the ballgame or TLUD
cooking taking place.<br>
<br>
Paul<br>
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Regards </div>
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Crispin </div>
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ý<br>
<div>Crispin,<br>
<br>
I am sure that Bill and Gordon in New Mexico (and others
including mysel\f) will appreciate more info (details, photos,
sizes, etc) about the continuous TLUDs with bottom feeding.
Please try to provide.<br>
<br>
When mixing in the previously made char into the future batches
of fuel, there are two concerns:<br>
<br>
1. Cannot mix in hot, glowing char (which would ignite low into
the columnof fuel), Therefore must be extinquished, which is an
extra step.<br>
<br>
2. Char from a TLUD at whatever temperature of pyrolysis will
essentially be "inert" material into a next batch to be
pyrolyzed at the same temperature. No gain. Just filling
space. [[ But one exception: created char can pick up some
of the volatiles that are rising through it. Those volatiles
would be elegible to be released for making energy in the second
round. As far as I know, those volatiles would be a very very
small percentage of the energy in the processes. }} So why
bother to do it, UNLESS the intention is to burn the created
char (which should not be done in a TLUD).<br>
<br>
I agree that anyone is allowed to test and experiment with any
methods and materials. What we are awaiting are reports of
adoption of methods etc by significant numbers of appropriate
users.<br>
<br>
Paul<br>
<br>
<pre class="moz-signature" cols="72">Doc / Dr TLUD / Prof. Paul S. Anderson, PhD
Email: <a class="moz-txt-link-abbreviated" href="mailto:psanders@ilstu.edu" moz-do-not-send="true">psanders@ilstu.edu</a>
Skype: paultlud Phone: +1-309-452-7072
Website: <a class="moz-txt-link-abbreviated" href="http://www.drtlud.com" moz-do-not-send="true">www.drtlud.com</a></pre>
<div class="moz-cite-prefix">On 9/28/2017 10:29 AM, Crispin
Pemberton-Pigott wrote:<br>
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<p class="MsoNormal"><span style="color:windowtext">Dear
Paul</span></p>
<p class="MsoNormal"><span style="color:windowtext"> </span></p>
<p class="MsoNormal"><span style="color:windowtext">Thanks
for the ideas about char. I want to correct a couple of
impressions.</span></p>
<p class="MsoNormal"><span style="color:windowtext"> </span></p>
<p class="MsoNormal"><b><span style="color:windowtext"
lang="EN-US">></span></b>And users can continually
drop in more fuel, which is "trickle feeding"and requires
user attention. TLUDs are batch units.<span
style="color:windowtext"></span></p>
<p class="MsoNormal"><span style="color:windowtext"> </span></p>
<p class="MsoNormal"><span style="color:windowtext">This is
only true some of the time. TLUD burners are frequently
(often, not rarely) built at small industrial scale
using batch-push feeding from below. I was surprised to
find that the Stove Development Centre in Ulaanbaatar
has been making a number of these units – the surprise
coming from the fact that none of the domestic candidate
stoves had used this system. I saw one being repaired in
August. Being a TLUD does not mean it has to be a
single batch unit.
</span></p>
<p class="MsoNormal"><span style="color:windowtext"> </span></p>
<p class="MsoNormal"><span style="color:windowtext">The char
or charred fuel is not placed on top of the fresh fuel –
it is mixed in and forms part of the fuel. I don’t know
what the upper limits of content are, I believe for
different stoves there are different limits. The HTP
spreadsheet was modified in 2013 or so to accommodate
this sort of ‘limited ability to recycle processed fuel’
and still produce the correct ‘as burned’ (AB) fuel
analysis that forms the basis of the chemical mass
balance calculation.
</span></p>
<p class="MsoNormal"><span style="color:windowtext"> </span></p>
<p class="MsoNormal"><span style="color:windowtext">Next,
with reference to the recycling of fuel from one burn to
the next:</span></p>
<p class="MsoNormal"><span style="color:windowtext"> </span></p>
<p class="MsoNormal"><span style="color:windowtext">></span>Also,
apart from the lab testing, is there evidence that the
Indonesian cooks are actually using the stove as it was
being used in the lab?
<span style="color:windowtext"></span></p>
<p class="MsoNormal"><span style="color:windowtext"> </span></p>
<p class="MsoNormal"><span style="color:windowtext">That is
not up to the lab performing the test. If a manufacturer
comes out with a novel method of construction and
operation, it is up to the lab to test it as designed,
not to speculate about home someone in future might use
it. </span></p>
<p class="MsoNormal"><span style="color:windowtext"> </span></p>
<p class="MsoNormal"><span style="color:windowtext">For a <i>project</i>
it makes a difference and a project might not adopt a
stove for promotion if the cultural conflicts with how
it works. In short, the testing does not stand in the
way of innovation. There is a clear separation between
the invention and testing of products from the projects
that may or may not use them. I realise that there has
been a confabulation of projects and test protocols in
the past. That should end. A test method should be
technology neutral.</span></p>
<p class="MsoNormal"><span style="color:windowtext"> </span></p>
<p class="MsoNormal"><span style="color:windowtext">That
said, a test protocol specific to a project is also
valid. On project I was associated with required that
the stoves be mis-operated and the performance reported
because ‘obvious misuse’ is an accepted risk and we
wanted to know the implications.</span></p>
<p class="MsoNormal"><br>
<span style="color:windowtext">></span>These stoves can
be operated in different ways.
<span style="color:windowtext"></span></p>
<p class="MsoNormal"><span style="color:windowtext"> </span></p>
<p class="MsoNormal"><span style="color:windowtext">Yes, but
it would be good if you did not limit the operation of a
TLUD to a batch or trickle-feed mode. There are other
products around. TLUD coal and pellet and briquette
burners are quite common. I expect one day the TLUD
promoters will accept this as a standard operating
technique because it overcomes several of the attested
shortcomings of batch-loaded stoves.</span></p>
<p class="MsoNormal"><span style="color:windowtext"> </span></p>
<p class="MsoNormal"><span style="color:windowtext">></span>How
many of each of those units (Todd's or the Indonesian
ones) are in daily use in households? I hope that the
numbers of users are VERY high. Please send details.<span
style="color:windowtext"></span></p>
<p class="MsoNormal"><span style="color:windowtext"> </span></p>
<p class="MsoNormal"><span style="color:windowtext">I am not
sure stoves are listed by operating mode. Those that are
claimed to be operating as TLUDs with recycled fuel
could be identified by brand and the numbers (probably)
extracted from the CSI Indonesia aggregated sales
numbers. It is in the thousands I suppose. I am not the
one to ask.
</span></p>
<p class="MsoNormal"><span style="color:windowtext"> </span></p>
<p class="MsoNormal"><span style="color:windowtext">Regards</span></p>
<p class="MsoNormal"><span style="color:windowtext">Crispin</span></p>
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