<div dir="ltr">Hi Paul,<div><br></div><div>I think that the denser pellets might not maintain the flame as easily as the .56g small pellets described by Tom. I wonder if for clean emissions the TLUD has to be tuned to burn the fuel even if the tuning is easily accomplished by adjusting primary and secondary air. </div>
<div><br></div><div>Best,</div><div><br></div><div>Dean</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Thu, Mar 6, 2014 at 11:35 AM, 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:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<div>Stovers,<br>
<br>
Crispin wrote, in agreement with Dean, and I have added the
emphasis on Crispin's words:<br>
<blockquote type="cite"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">The
air flow through the pellets strongly affects the way they
burn<b><big><i><u> if the device is constructed such that the
fuel contributes a significant element of air control.</u></i></big></b></span></blockquote>
Simply, stove devices should NOT be constructed for a specific
fuel UNLESS that fuel is specified and can be supplied. The
issue is just like using an incorrect grade of gasoline in your
automobile. LEADED gas will not burn like unleaded. Super
premium is different from regular. And pellet sizes are
different from each other (assuming that the pellet materials were
also the same, which might or might not have been the case in what
Dean has mentioned.)<br>
<br>
Most of the TLUD stoves that have been tested have not been the
ones with serious control of the primary air supply. Hence the
problem that Dean mentions. <br>
<br>
I do not know of any tests of emissions from different pellet
sizes that have been conducted in TLUD stoves that have serious
control of primary air. One more research topic to add to the
list of things to do.<br>
<br>
Personal comment: I have had my hand involved with the
development of the "Champion Family" of TLUD stoves:<br>
1. Champion TLUD that won the first Cat Pee Award at Aprovecho
Stove Camp 2005. We just had a blocker on the primary air inlet.<br>
<br>
2. Champion by Servals (India): Still with a rather rudimentary
control of primary air (a disk into a cone).<br>
<br>
3. Mwoto (for BEIA project by CREEC in Uganda): It has a
slider control of primary air directly on the fuel cylinder, but
we had not perfected it then and did not make much of an issue
about closing off the primary air through tiny gaps such as at the
ends the strips that hold the slider in place.. <br>
<br>
4. Quad (by Awamu in Uganda): We made a better slider door and
placed it onto a "snout" for primary air. But we did not seal
with great care. Also, the tab-and-slot construction left tiny
air leaks that proved to be too much uncontrolled air. This was
discovered at the July 2013 Stove Camp at Aprovecho where we
progressively sealed better and better the stoves being tested.
The best sealed stove won one of the Cat Pee Awards. That was
seven months ago, and we have stopped production of the Quad stove
with tab-and-slot construction (and have sealed better the
existing units.)<br>
<br>
5. Troika Bingwa (by Awamu in Uganda): This stove is just
getting out to the users. It has a tightly sealed fuel chamber
with a slider over the primary air entry.<br>
<br>
Note: Do not underestimate the impact of even a very very very
small leak of primary air if you expect to have turn-down of a
TLUD stove.<br>
<br>
Of all the other TLUD stoves, most have no attempt to control the
primary air. The unit by Prof. Nurhuda does seem to have
excellent primary air control (but I do not have one of those
stoves, and there are additional issues to be considered.)<br>
<br>
I hope that these comments are useful for everyone dealing with
natural draft TLUD stoves. Comments pro or con are most welcome.<br>
<br>
Paul<br>
<br>
<pre cols="72">Doc / Dr TLUD / Prof. Paul S. Anderson, PhD
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>
On 3/6/2014 11:38 AM, Crispin Pembert-Pigott wrote:<br>
</div>
<blockquote type="cite">
<div>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Dear
Friends<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">I
agree with Dean on this score. The air flow through the
pellets strongly affects the way they burn if the device is
constructed such that the fuel contributes a significant
element of air control.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">These
devices<u></u><u></u></span></p>
<p class="MsoNormal"><br>
<span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Are
‘cubers’ in that they are producing densified lumps that can
be put into a stove. But they will work best in a large
stove such as is used in China for space heating and
cooking. The input material is straw and other stover.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">The
mechanism is an eccentric roller running inside a perforated
cage at maybe 60-100 RPM. As Tom notes, power consumption is
about 110 kW.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">So
far I don’t think the product is economically viable as
there is a subsidy involved. What we need is a breakthrough
technology that will make densified fuel without the need
for heat.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Regards<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Crispin<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"" lang="EN-US"><u></u> <u></u></span></b></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<div>
<p class="MsoNormal">Hi Paul,<u></u><u></u></p>
<div>
<p class="MsoNormal"><u></u> <u></u></p>
</div>
<div>
<p class="MsoNormal">I have seen the very small pellets sold
for heating stoves in the US burn very cleanly. Larger
sized pellets did not burn as cleanly. <u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"><u></u> <u></u></p>
</div>
<div>
<p class="MsoNormal">Best,<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"><u></u> <u></u></p>
</div>
<div>
<p class="MsoNormal">Dean<u></u><u></u></p>
</div>
</div>
</div>
<br>
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