<html><head><style type='text/css'>p { margin: 0; }</style></head><body><div style='font-family: Arial; font-size: 12pt; color: #000000'><style>p { margin: 0pt; }</style><div style="font-family: Arial; font-size: 12pt; color: rgb(0, 0, 0);"><p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"><font face="Arial">Paal (and 2 lists)<br>
</font></span></p><p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><br><span style="font-size: 10pt;" lang="EN-GB"></span></p><p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"><font face="Arial">
Thanks for the two nice responses (below) sent a few days ago. I have
combined them here to improve readability. Your associate (?) Otto
Formo has done a nice job of explaining the background. I hope you can
add more on the charcoal output mechanism and produced-char uses (the
Biochar side) - as well as the following questions.<br></font></span></p><p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><br><span style="font-size: 10pt;" lang="EN-GB"></span></p><p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"><font face="Arial"><strong>A. The second message (almost same timing as the next) said:</strong><br></font></span></p><p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"><font face="Arial"><br></font></span></p><p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"><font face="Arial">Crispin</font></span></p>
<p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"><font face="Arial">To your infomation if Dean dont' have the exact
figures by hand the TLUD-ND I made at Stove Camp 2009 had the following
settings. <span style=""> </span></font></span></p>
<p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"><font face="Arial"> The
combustion chamber <span style=""> had a </span>diameter
150mm and was 180 h</font></span></p>
<ul style="margin-top: 0cm;" type="disc"><li style="margin: 0cm 0cm 0pt;" class="MsoNormal"><font face="Arial"><span style="font-size: 10pt;" lang="EN-GB">55
mm</span><span style="font-size: 10pt;" lang="EN-GB"> free
space from concentration lid up to the pot</span></font></li><li style="margin: 0cm 0cm 0pt;" class="MsoNormal"><font face="Arial"><span style="font-size: 10pt;" lang="EN-GB">105
mm</span><span style="font-size: 10pt;" lang="EN-GB"> hole
in concentration lid</span></font></li><li style="margin: 0cm 0cm 0pt;" class="MsoNormal"><font face="Arial"><span style="font-size: 10pt;" lang="EN-GB">6
mm</span><span style="font-size: 10pt;" lang="EN-GB"> split
between concentration lid and top of thee combustion chamber - 4x15mm for the
stand for 2<sup>nd</sup> air</span></font></li><li style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"><font face="Arial">5
five mm holes 75
mm up from the bottom on the side of the combustion
chamber </font></span></li><li style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"><font face="Arial"> <span style="font-weight: bold;">[RWL1:
Was the fuel always loaded below this level? If not, then what is the
need for these holes? How deep was the fuel load for the test results
given below? Some of next questions apply here also depending on how
high the fuel loading is/was.]</span><br></font></span></li><li style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"><font face="Arial">5
five mm holes 25
mm up from the bottom on the side of the combustion
chamber </font></span></li><li style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"><font face="Arial"> <span style="font-weight: bold;">[RWL2:
The purpose of these I also don't understand - believing the 13 (next)
could do the full job for supplying primary air (if you want to make
char). I would think that secondary air entry at these holes will
quickly consume all the char above them and make it harder to combust
the still-upcoming pyrolysis gases from below. On the other hand, maybe
this is useful in some cooking tasks (such as a water boiling test). ]</span><br></font></span></li><li style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"><font face="Arial">13
five mm holes at the bottom plate for 1<sup>st</sup>
air</font></span></li><li style="margin: 0cm 0cm 0pt;" class="MsoNormal"><font face="Arial"><span style="font-size: 10pt;" lang="EN-GB">15
mm</span><span style="font-size: 10pt;" lang="EN-GB"> space
between combustion chamber an cover for preheating of
2<sup>nd</sup>.air</span></font></li><li style="margin: 0cm 0cm 0pt;" class="MsoNormal"><font face="Arial"><span style="font-size: 10pt;" lang="EN-GB"> <span style="font-weight: bold;">[RWL3a:
Not quite understanding this last. I'd rather see secondary air being
heated as it rises rather than being drawn down - holes at the bottom
for this? As for some of the first dimensions, a small cross-section
diagram would be helpful on this detail. I think you show much larger
dimensions for some of the air entries in the several videos listed
below. Perhaps you can explain any differences and reasons for same.
Which is the newer design?]</span><br style="font-weight: bold;"></span></font></li></ul><br style="font-weight: bold;"><strong>B. Few more below on your first of the two messages.</strong><br><br>----- Original Message -----<br>From: "Paal wendelbo" <paaw@online.no><br>To: "Til: \"Discussion of biomass cooking stoves\"" <stoves@lists.bioenergylists.org><br>Sent: Friday, December 3, 2010 4:17:32 AM<br>Subject: Re: [Stoves] K Smith Article in Energy for Sustainable Development<br><br>
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<p style="text-indent: 35.4pt; margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB">When I started my work on simple cooking
stoves late 1980ties I did not know any thing about the concept of TLUD-ND apart
from the fact we used it making smokeless fire when we stayed in the forest
during the 2<sup>nd</sup> ww Illegal hunting. By coincidence, after a lot of
trying and failing I happen to make a perfect simple cooking stove tested at
Copenhagen Technical high school in 1988 and found completely clean burning. .It
was introduced in Malawi in 1998
with stamped grass as fuel. In Mozambique in 1990, with cashew nut
peals as fuel. In 1989
in Ghana, with chopped slabs as fuel. In
Tanzania in 1990,
in Uganda in 1994 with straw and chopped wood as fuel,
where it was given the Acholi name Peko Pe (no problem), in Ethiopia with
briquettes of cowdung and straw as fuel, In Senegal with compressed grownut
peals as fuel. with chopped wood and in China in 2003and In Zambia 2008 <span style=""> </span>with chopped wood All places the same
stove locally made by local tinsmiths with the tools they had and from plane
metal sheets or scrap metal sheets. All working perfect without any smoke and
little soot.. </span></p>
<p style="text-indent: 35.4pt; margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB">At Trade Fair exhibition in Kampala 1997 we
were selling 500 stoves in two days at market prise That time
5$.</span></p>
<p style="text-indent: 35.4pt; margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB">At <span style=""> </span>Aprovecho Stove Camp 2009 I made one by
memory of a 3<span style=""> </span>litres tin and some
leftover sheets, it was tested and found clean burning and given the Kirk Smiths
Award</span></p>
<p style="text-indent: 35.4pt; margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"> <span style="font-weight: bold;">[RWL3b: And presumably the same as the numbers given below and above?]</span><br>
</span></p>
<p style="text-indent: 35.4pt; margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"> </span></p>
<p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB">Fuel to Cook 5L </span></p>
<p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB">(8 50/1500) g<span style="">
</span>768.8</span></p><p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"> <span style="font-weight: bold;">[RWL4:
I don't understand the first (8 50/1500) numbers. I presume the 768.8
grams somehow took account of char produced? (In 28 minutes?)</span><br></span></p>
<p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB">CO to Cook 5L (20)<span style="">
</span>23.0</span></p><p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"> <span style="font-weight: bold;">[RWL5:
the "20" means?? The 23 is grams ? Out of 768.8? Same questions for
particulates data (1500? 223.1?) next - which latter must be in mg?]</span><br></span></p>
<p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB">PM to Cook 5L (1500<span style="">
</span>223.1</span></p>
<p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB">15,000/25,000mkJ<span style=""> <br></span></span></p><p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"><span style=""> <span style="font-weight: bold;">[RWL6:
why two numbers above? The units aren't familiar. For almost
anything biomass, I would expect about 17 MJ/kg; with your input kg, I
expect more like 12 MJ. Anybody measure fuel moisture content?]</span>
</span></span></p>
<p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB">Energy to Cook 5L<span style="">
</span>14,807</span></p><p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"> <span style="font-weight: bold;">[RWL7: Units probably kJ?]<br></span></span></p><p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"><span style="font-weight: bold;"></span>Time to boil 5
litres min<span style="">
</span>28.1</span></p>
<p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"> <span style="font-weight: bold;">[RWL7':
This can be converted to an average (using my estimate) of (12,000 kJ/
(28.1 minutes * 60 seconds) = 200/28.1 = 7.1 kW. It would be helpful if
this number was part of any stove data. I feel this number is too high
for normal cooking and simmering - but it depends a lot on the heat
transfer efficiency (about which we know nothing in this test)]</span><br>
</span></p>
<p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB">CO2 to Cook 5L708.6<span style="">
</span>708.6</span></p><p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"> <span style="font-weight: bold;">[RWL8:
If you consumed 768.8 grams of fuel, I would expect the CO2 weight to
be much higher than 708.6 grams - unless there was a lot of char
produced. Hope you or Dean can explain this number. I am thinking you
probably didn't use this much fuel - and that char production hasn't
been properly accounted for (since I think Dean should know the CO2
exhaust gas content pretty well. How often is a CO2 measurement
recorded? Your (anyone's) thoughts?]</span><br></span></p>
<p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"><span style="">
</span></span></p>
<p style="text-indent: 35.4pt; margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB">Biochar has entered the arena and made the
discussion about cooking stoves a bit more interesting. And Dean Still is right
when he says by TLUD-ND you can choose between energy for simmering or biochar.
Just by stopping cooking process when flame is ended you will have about
150-200
gram of biochar.</span></p><p style="text-indent: 35.4pt; margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"><span style="font-weight: bold;">[RWL9: Which must come into play in your above data - but I don't see how it was handled..
I have not liked the way char production is handled in the USAID
formulas from 20 years ago. Can you give the formula so I can re-raise
that topic?]</span><br>
</span></p>
<p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"><span style="">
</span>Peko Pe which mean “no problem” according to the Acholi tribe women have
a problem and that is infrastructure on fuel. Fuel, stove and user is one unit
which can not be separated, If you don’t have the fuel to an appropriate price
you will not manage..</span></p>
<p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB">Fuel and stoves is a part of the social life in a community, a part
of the commerce and the communication in the society.. </span></p>
<p style="text-indent: 35.4pt; margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB">The charcoal business is the key to a
successful approach. They have the full infrastructure intact and can easy
change from charcoal to alternative biomass for cooking. <span style="font-weight: bold;">[RWL10:
I hope you are right on this. My hope is that today's charcoal
sellers (or someone maybe helping them) can supply
wood/grass/pellets/briquettes and receive back about 25% char in
exchange - and later handle all the paper work for getting carbon
credits (after assuring the char made into into the ground). Do you
think that could happen?] <br>
</span></span></p>
<p style="text-indent: 35.4pt; margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"><span style="font-weight: bold;"><br>
</span></span></p>
<p style="text-indent: 35.4pt; margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"><span style="font-weight: bold;">.</span>The local tinsmiths
have the tools and the knowledge for production. They need only some guidelines,
a template and customers for this simple technology.</span></p>
<p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"> <a href="http://www.youtube.com/watch?v=amaUDK6VyRg" target="_blank">http://www.youtube.com/watch?v=amaUDK6VyRg</a><br><a href="http://www.youtube.com/watch?v=gi3Xx7NtTGw&feature=related" target="_blank">http://www.youtube.com/watch?v=gi3Xx7NtTGw&feature=related</a><br><a href="http://www.youtube.com/watch?v=dsfuVGBi4fc&feature=related" target="_blank">http://www.youtube.com/watch?v=dsfuVGBi4fc&feature=related</a></span></p>
<p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-size: 10pt;" lang="EN-GB"></span> <br style="font-weight: bold;">
</p>
<p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-weight: bold;">[RWL11: It seems to me that in both the videos and the description by Dean Still of
TLUD testing that there has been no means of varying your primary air.
This is fine in a speed test to bring 5 L of water to boil - but is
missing a valuable feature of TLUDs (or any modern stove). Can you
clarify whether you have been varying primary air magnitude in any way?</span><br>
</p>
<p style="margin: 0cm 0cm 0pt; font-weight: bold;" class="MsoNormal"><br>
</p>
<p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span style="font-weight: bold;">Thanks in advance for any more data. Ron</span><br>
</p>
<p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><br>
</p>
<p style="margin: 0cm 0cm 0pt;" class="MsoNormal"><span lang="EN-GB"><font size="3">With regards Paal W </font><a href="mailto:paaw@online.no" target="_blank"><font size="3">paaw@online.no</font></a><font size="3">
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