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<div class="moz-cite-prefix">Dear Kobus and all,<br>
<br>
Retort: When 50/50 inner and outer amounts of fuel as Kobus has
mentioned: the Outer burning XX kg yields zero biochar;
Inside retort yields 20 to 30& of XX kg, net of 10 to 15% of
total fuel used. <br>
<br>
(Note: charcoal yields from inside a retort of greater than 25
or 30% indicate considerable volatile matter is in the charcoal,
which is not generally considered good for the plants/soils.
Beware of charcoal that is 40+% of original fuel weight. It will
burn in a charcoal stove probably with some limited smoke, but is
not good as biochar.)<br>
<br>
TLUD: One batch, expect about 20% yield by weight. Nearly
double the net weight output, and not needing double barrels, etc.<br>
<br>
Fines are a result of size of feedstock. If making biochar,
fines are fine (pun intended). Or fines can be briquetted quite
easily if sold to the charcoal market.<br>
<br>
Biggest problem I see with many attempts to make TLUD-style
barrel-size charcoal makers is the poor quality of the lid or top
to allow in secondary air that goes to the concentrator hole. If
this sentence does not make sense to someone, then that person has
not studied the basics of TLUD operation. <br>
<br>
Users should start with small TLUDs (like McLaughlin's "1-G
Toucan" out of tincans - plans are on the web) so that they know
that the TLUD fires CAN and should be very clean burning. There
is no reason to have smoky TLUDs when using 200 liter barrels
unless using wet fuel or not yet adjusting the TLUD to the fuel at
hand.<br>
<br>
Paul<br>
<br>
<pre class="moz-signature" cols="72">Paul S. Anderson, PhD aka "Dr TLUD"
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>
On 9/30/2012 8:54 AM, Kobus Venter wrote:<br>
</div>
<blockquote
cite="mid:1349013285.41209.YahooMailNeo@web140002.mail.bf1.yahoo.com"
type="cite">
<div style="color:#000; background-color:#fff; font-family:times
new roman, new york, times, serif;font-size:12pt">
<div>Tom, Paul, Dan and others, <br>
</div>
<div><br>
</div>
<div style="color: rgb(0, 0, 0); font-size: 16px; font-family:
times new roman,new york,times,serif; background-color:
transparent; font-style: normal;">I have gone away a bit from
the TLUD principle as I started from a very polluting open top
burn approach and using feedstock that is not uniform in
particle size. Very wasteful, and as in Dan's case I ended up
with a lot of fines
(<a class="moz-txt-link-freetext" href="http://vuthisa.files.wordpress.com/2012/09/img00177.jpg">http://vuthisa.files.wordpress.com/2012/09/img00177.jpg</a>). The
only cost effective way that I could improve emissions of the
Transportable Metal Kiln was to convert it into a retort, by
using the heat from the conventional burn to heat the inner
retorts. The flow rate of the air through the outer burn will
be high, probably around 1.5 m3/sec and the quantity of
feedstock necessary to provide the heat to the inner retorts
before the reaction becomes exothermic will probably match the
closely packed feedstock volumetrically inside the 3 x 55 gal
drums, which will ultimately yield the biochar. The burn is
seen as successful only if ash remains in the outer vessel and
all the biomass inside the 55 gal drums is pyrolysed. I don't
need a TLUD type flow rate to ensure complete carbonisation,
but the consumed wood in the outer drum has to be included in
the overall yield percentage calculation. The addition of a
conical lid and chimney (much akin to the New Hampshire metal
kiln design) has increased the draft needed to vent
emissions. In the conventional open drum burn I would place
±550 kg feedstock and end up with 120 kg charcoal, but 50%
will be fines. In the 3-drum retort I would probably also use
550 kg but end up with ???? I would not like to venture an
answer at this early stage, but hopefully end up with more
than just 60 kg of biochar. The principal advantages of my
three drum retort should be the 25% yield of char from the
retort contents, coupled with the ability to use lower quality
fuel as the starter fuel (outside the drum) and the
self-stopping of the retort design (better safety, no need fro
water), and the self-running aspect (light it and step
back). </div>
<div><br>
</div>
<div style="color: rgb(0, 0, 0); font-size: 16px; font-family:
times new roman,new york,times,serif; background-color:
transparent; font-style: normal;"><a class="moz-txt-link-freetext" href="http://vuthisa.files.wordpress.com/2012/09/slits_drum.jpg">http://vuthisa.files.wordpress.com/2012/09/slits_drum.jpg</a></div>
<div style="color: rgb(0, 0, 0); font-size: 16px; font-family:
times new roman,new york,times,serif; background-color:
transparent; font-style: normal;"><a class="moz-txt-link-freetext" href="http://vuthisa.files.wordpress.com/2012/09/dscf335.jpg">http://vuthisa.files.wordpress.com/2012/09/dscf335.jpg</a></div>
<div style="color: rgb(0, 0, 0); font-size: 16px; font-family:
times new roman,new york,times,serif; background-color:
transparent; font-style: normal;"><a class="moz-txt-link-freetext" href="http://vuthisa.files.wordpress.com/2012/09/branches_lid-removed2.png">http://vuthisa.files.wordpress.com/2012/09/branches_lid-removed2.png</a></div>
<div style="color: rgb(0, 0, 0); font-size: 16px; font-family:
times new roman,new york,times,serif; background-color:
transparent; font-style: normal;"><a class="moz-txt-link-freetext" href="http://vuthisa.files.wordpress.com/2012/09/bottom.jpg">http://vuthisa.files.wordpress.com/2012/09/bottom.jpg</a><br>
</div>
<div style="color: rgb(0, 0, 0); font-size: 16px; font-family:
times new roman,new york,times,serif; background-color:
transparent; font-style: normal;"><br>
</div>
<div style="color: rgb(0, 0, 0); font-size: 16px; font-family:
times new roman,new york,times,serif; background-color:
transparent; font-style: normal;">Regards</div>
<div style="color: rgb(0, 0, 0); font-size: 16px; font-family:
times new roman,new york,times,serif; background-color:
transparent; font-style: normal;"><br>
</div>
<div style="color: rgb(0, 0, 0); font-size: 16px; font-family:
times new roman,new york,times,serif; background-color:
transparent; font-style: normal;">Kobus<br>
</div>
<br>
<div style="color: rgb(0, 0, 0); font-size: 16px; font-family:
times new roman,new york,times,serif; background-color:
transparent; font-style: normal;">********************************************************************************<br>
</div>
<div>AD, Paul, Kobus and others. Many thanks for the
suggestions. <br>
<br>
What is the largest practical size (kg fuel/hr, kW) for a
single TLUD with a<br>
clean stack for heat recovery? There must be a limit to the
air penetration<br>
to get a clean gas burn form a natural draft stack or even a
fan driven<br>
TLUD. <br>
<br>
Tom <br>
<br>
<span></span></div>
<div style="color: rgb(0, 0, 0); font-size: 16px; font-family:
times new roman,new york,times,serif; background-color:
transparent; font-style: normal;"><br>
<span></span></div>
<div style="color: rgb(0, 0, 0); font-size: 16px; font-family:
times new roman,new york,times,serif; background-color:
transparent; font-style: normal;"><br>
<span></span></div>
<pre wrap=""><a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://www.vuthisa.com/">http://www.vuthisa.com</a>
Twitter: @vuthisa <a moz-do-not-send="true" class="moz-txt-link-freetext" href="https://twitter.com/vuthisa">https://twitter.com/vuthisa</a>
Facebook: <a moz-do-not-send="true" class="moz-txt-link-abbreviated" href="http://www.facebook.com/Vuthisa">www.facebook.com/Vuthisa</a>
LinkedIn: <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://za.linkedin.com/in/vuthisa">http://za.linkedin.com/in/vuthisa</a></pre>
<div style="color: rgb(0, 0, 0); font-size: 16px; font-family:
times new roman,new york,times,serif; background-color:
transparent; font-style: normal;"><br>
<span></span></div>
<div style="color: rgb(0, 0, 0); font-size: 16px; font-family:
times new roman,new york,times,serif; background-color:
transparent; font-style: normal;"><span></span></div>
<br>
<div style="font-family: times new roman, new york, times,
serif; font-size: 12pt;">
<div style="font-family: times new roman, new york, times,
serif; font-size: 12pt;"><br>
</div>
</div>
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</blockquote>
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