<div>Dear Paul,</div><div> </div><div>Did you see that a TLUD, natural draft by the way, did best in Jim Jetter's recent tests? There's no problem testing TLUDs that I experience especially using a bomb calorimeter to know the remaining values. </div>
<div> </div><div>I test TLUDs frequently and am not having problems. The problem with stoves is not in the testing. The problem is when they are not tested. Developing the TLUD so it's both super clean and super fuel efficient happens by testing, changing, testing.</div>
<div> </div><div> </div><div>Best,</div><div> </div><div>Dean</div><div> </div><div><br><br> </div><div class="gmail_quote">On Fri, Dec 7, 2012 at 10:03 PM, Paul Anderson <span dir="ltr"><<a href="mailto:psanders@ilstu.edu" target="_blank">psanders@ilstu.edu</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;padding-left:1ex;border-left-color:rgb(204,204,204);border-left-width:1px;border-left-style:solid">
<div text="#000000" bgcolor="#FFFFFF">
<div>Crispin and all,<br>
<br>
With the exception of one point and one wording, I can agree with
Crispin's comments and I hope others also find these observations
and dialogues helpful.<br>
<br>
One wording problem:<br>
<span style="color:rgb(31,73,125);font-family:"Calibri","sans-serif";font-size:11pt"><u></u><u></u></span>
<p class="MsoNormal" style="margin-bottom:12pt"><span style="color:rgb(31,73,125)">Paul wrote: ></span><br>
Just please do not have testing that poisons the waterhole for
those who are working with TLUD and other micro-gasifier stoves.<span style="color:rgb(31,73,125)"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:rgb(31,73,125);font-family:"Calibri","sans-serif";font-size:11pt">Crispin
replied:<br>
Well, that is well put. The current WBT calculations do
exactly that. There are several ‘fatal flaws’ which means the
final number(s) misrepresent the true performance of the
product. Some stoves are accidentally ‘optimised’ to perform
well on a given test but this does not improve their actual
performance when viewed through the lens of a more rigorous
test.<u></u><u></u></span></p>
<p class="MsoNormal"><br>
</p>
Comment: "The current WBT calculations do exactly that."
refers to my sentence that included the "not". So I think that
Crispin is saying that the current WBT actually DOES poison the
waterhole.<br>
<br>
One exception (or in need of clarification by Crispin). I leave
below the entirety of "Item 3" so that it is not out of context,
but my point is this:<br>
<br>
With a good solid fuel and a sufficiently large TLUD (like the
Quad TLUD), you only need ONE fueling of the batch to complete
BOTH the boiling and simmering parts of a complete WBT. So if
the unit is loaded with fuel that would continue to pyrolyze AFTER
the completion of the test, that would mean that UNNECESSARY fuel
is being charged as part of the Fuel efficiency (fuel
consumption). And that was clearly the case in the 3 test runs
of the Quad stove. Look at the total time of operation of each
batch of fuel.<br>
<br>
Note the 3 different sizes of the pieces (shown in the photos) use
in the 3 runs. We were learning about fuels and extending the
operating time as well as about stove test results. (Should not
mix 2 objectives, but time and money are rather limited when I am
paying for it all myself.) We learned that we can get more fuel
into the fuel chamber if the pieces are thicker, and that the
total time will be longer (because pyrolysis to the center of
thick pieces is longer and slower.) <br>
<br>
And believe me, the cooks seem to be much more interested in the
length of the burning time than they are about any certified
correctly-conducted measurements for a WBT. I guess we Stover
designers are serving two masters: Those who check test results
before allocating any funding, and those who use the stoves to
cook meals.<br>
<br>
So, if the TLUD could complete the full WBT test with only 1.2 kg
of fuel on each of the 3 test runs, then the FUEL consumption
would be 1.2 kg instead of the 1.6 kg average that Crispin
calculated from the data sheets.<br>
<br>
So, let's make sure that FUEL efficiency is related to the task of
the WBT and not to the capacity of fuel in a batch fuel chamber.
Let's have test results that are clear about what is being stated.<br>
<br>
(the referenced messages are below) Paul (In Kampala until
17 Dec)<br>
<br>
<br>
<br>
On 12/7/2012 5:20 PM, Crispin Pemberton-Pigott wrote:<br>
</div>
<blockquote type="cite">
<div><span style="color:rgb(31,73,125);font-family:"Calibri","sans-serif";font-size:11pt"><u></u><u></u></span>
<div>
<p class="MsoNormal"><span style="color:rgb(31,73,125);font-family:"Calibri","sans-serif";font-size:11pt"><u></u> Paul
wrote:<br>
<u></u></span></p>
<p class="MsoNormal"><span style="color:rgb(31,73,125)">></span>3.
This could imply that the stove was operated until the end
of pyrolysis even if that was many minutes after the
complete WBT was conducted. <span style="color:rgb(31,73,125)"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:rgb(31,73,125);font-family:"Calibri","sans-serif";font-size:11pt"><u></u>Crispin
replied: <br>
<u></u></span></p>
<p class="MsoNormal"><span style="color:rgb(31,73,125);font-family:"Calibri","sans-serif";font-size:11pt">I
am not making that assumption t{h]ough it is one
possibility. For example a stove may have a fire shut-off
mechanism capable of extinguishing the flame within a
short time. I do not want to anticipate what might be
invented. Because the nature of a test to get a particular
metric requires the fire to be stopped at the end, it is
reasonable to make a plan to do so. There is a method
called the Burn-Out Test which was specifically designed
to test stoves with pellet-like fuel that cannot easily be
shut down and which in any case contain all sorts of
half-burned bits of fuel. Dr Taylor rated that method at
about 15% error.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:rgb(31,73,125);font-family:"Calibri","sans-serif";font-size:11pt"><u></u> <u></u></span></p>
<p class="MsoNormal">PARTIAL SOLUTION that creates havoc is
that the SAME stove could be operated identically with the
amount of fuel carefully calculated to have pyroylsis end
within a minute after the WBT was completed. <span style="color:rgb(31,73,125)"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:rgb(31,73,125);font-family:"Calibri","sans-serif";font-size:11pt"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="color:rgb(31,73,125);font-family:"Calibri","sans-serif";font-size:11pt">Although
this is possible, it is not necessary. The performance of
any task like stir-frying, water heating or fish drying
can be measured in a couple of ways. I won’t bore you with
them now. The penalty for an un-extinguishable or
uncontrollable fire is real. They are, after all,
dislikeable traits.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:rgb(31,73,125);font-family:"Calibri","sans-serif";font-size:11pt"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="color:rgb(31,73,125)">></span>Fill
a TLUD with 3 kg of fuel for one test run, and then do it
with 1 kg for the second test run. <span style="color:rgb(31,73,125)"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:rgb(31,73,125);font-family:"Calibri","sans-serif";font-size:11pt"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="color:rgb(31,73,125);font-family:"Calibri","sans-serif";font-size:11pt">This
needs to be considered. I don’t see the obvious advantage
through this explanation.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:rgb(31,73,125);font-family:"Calibri","sans-serif";font-size:11pt"><u></u> <u></u></span></p>
<p class="MsoNormal" style="margin-bottom:12pt"><span style="color:rgb(31,73,125)">></span>In other words, Crispin's
correct statement (that the original loading of 1600 grams
of wood) is NOT related to the amount of FUEL used up until
the time of the completion of the WBT.<span style="color:rgb(31,73,125)"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:rgb(31,73,125);font-family:"Calibri","sans-serif";font-size:11pt">Actually,
it is. <u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:rgb(31,73,125);font-family:"Calibri","sans-serif";font-size:11pt"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="color:rgb(31,73,125);font-family:"Calibri","sans-serif";font-size:11pt">The
test of the Quad 2 was conducted in 2 phases wherein the
raw fuel was loaded twice (the amounts are indicated) and
both burned well past the completion of the relevant
section. The test as not completed in one go, in other
words. The remaining fuel was discounted to obtain the
fuel burned heat value (for getting the thermal
efficiency, fire to water). The total raw fuel needed to
conduct a complete WBT I calculated from the mass of raw
fuel burned for each section and the char produced in that
process. The average for the three tests was 1550 g of raw
fuel with a moisture content of 15%. If the stove was
loaded with 1600 g it would in in all likelihood complete
the hot start and simmer sections in one go.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="color:rgb(31,73,125);font-family:"Calibri","sans-serif";font-size:11pt"><u></u> <u></u></span></p>
<span style="color:rgb(31,73,125);font-family:"Calibri","sans-serif";font-size:11pt"><u></u><u></u></span></div>
</div>
</blockquote>
<br>
Paul S. Anderson, PhD aka "Dr TLUD"<br>
Email: <a href="mailto:psanders@ilstu.edu" target="_blank">psanders@ilstu.edu</a> Skype: paultlud Phone: <a href="tel:%2B1-309-452-7072" target="_blank" value="+13094527072">+1-309-452-7072</a><br>
Website: <a href="http://www.drtlud.com" target="_blank">www.drtlud.com</a><br>
</div>
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