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<div class="moz-cite-prefix">Julien,<br>
<br>
I am not sure that I said it that way, but I will try to answer<br>
<blockquote type="cite">Paul Anderson made an interesting comment
to me the other day. He wondered if as the size of the gas
flame increased, the flame became more fuel rich. Perhaps he
will elaborate on this for us.</blockquote>
As the gas flame increases because of adding more draft (chimney),
at the start the flame will be more fuel rich. Then it tries to
get more secondary air (to become "normal"), but that means more
flame, and more draft, etc. So it can take a while for the
system to normalize after a change (such as adding more chimney)
takes place. <br>
<br>
If that comment does not address what I said earlier, please
clarify the question. <br>
<br>
Paul<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>
On 12/12/2014 9:07 AM, Julien Winter wrote:<br>
</div>
<blockquote
cite="mid:CALv4xTxr=J=ZEeso9zREeWrEepiWk1=Osp+6Kwuh=nhxX6kB7g@mail.gmail.com"
type="cite">
<div dir="ltr">
<div>Hi Jock;</div>
<div><br>
</div>
<div>Thanks for your comment "Tweak one [design parameter] and
you tweak them all". The interactions in ND-TLUDs are
interesting. We don't see them so much in FD-TLUDs because
the fan overrides all. I developed the burner I am
using with prototype tin-can TLUDs and found that the
gasification rate was higher over the whole power curve with
moderately large secondary air holes. The size of the air
holes can't be too large, however, because as they become
larger they structure the air jets less and less, and you also
end up with big gaps between the holes. I have found that
round holes are better than rectangular holes, because the
round holes are better at self-regulating the flow of
secondary air as the flame size changes.</div>
<div><br>
</div>
<div>Geometry and placement of secondary air holes can affect
the distribution of burner draft between primary and secondary
air. Paul Anderson made an interesting comment to me the
other day. He wondered if as the size of the gas flame
increased, the flame became more fuel rich. Perhaps he will
elaborate on this for us.</div>
<div><br>
</div>
<div>The burner I am using is simple and robust. There are, of
course, other approaches to burners, as you and Kirk Harris
have shown.</div>
<div><br>
</div>
<div><br>
</div>
<div>All the best,</div>
<div>Julien.</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Fri, Dec 12, 2014 at 8:19 AM, Jock
Gill <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:jock@jockgill.com" target="_blank">jock@jockgill.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="auto">
<div>Julien,</div>
<div><br>
</div>
<div>If you increase draft you will increase the "pull"
on both secondary air and primary. This should allow you
to reduce the size, amount, of the primary air holes.</div>
<div><br>
</div>
<div>If you increase the amount of secondary air you will
reduce the amount of primary air. It is easier to pull
in secondary air than primary. The draft, primary and
secondary air are all tightly coupled in a non linear
system. It might be linear if the resistance in the
fuel bed were a constant, but as the fuel is pyrolized
the resistance is constantly changing. And of course
the variable amount of heat as the process progresses
also contributes to the non linearity of the system.</div>
<div><br>
</div>
<div>Tweak one and you tweak them all.</div>
<div><br>
</div>
<div>Cheers,</div>
<div><br>
</div>
<div>Jock </div>
<div><br>
<div>
<div style="font-family:UICTFontTextStyleBody">Jock
Gill</div>
<div style="font-family:UICTFontTextStyleBody">P. O.
Box 3</div>
<div style="font-family:UICTFontTextStyleBody">Peacham,
VT 05862</div>
</div>
<div style="font-family:UICTFontTextStyleBody"><br>
</div>
<div><a moz-do-not-send="true"
style="font-weight:bold;background-color:rgba(255,255,255,0)"
href="https://plus.google.com/_/notifications/emlink?emr=02164940119180120523&emid=CIn6jOiavboCFcgLTAodARYAAA&path=%2F102260924343967128597%2Fop%2Fu&dt=1383089746165&ub=50"
target="_blank"><font color="#000000">google.com/+JockGill</font></a></div>
<div><br>
</div>
Extract CO2 from the atmosphere!</div>
<div>
<div class="h5">
<div><br>
On Dec 11, 2014, at 7:20 PM, Julien Winter <<a
moz-do-not-send="true"
href="mailto:winter.julien@gmail.com"
target="_blank">winter.julien@gmail.com</a>>
wrote:<br>
<br>
</div>
<blockquote type="cite">
<div>
<div dir="ltr">
<div>Hi All;</div>
<div><br>
</div>
<div>Attached is an "experimental vignette". It
is a report on a small experiment conducted to
get a better understanding of natural draft
TLUD design.</div>
<div><br>
</div>
<div>The height of the riser above a gas burner
was doubled. The resulting increase in draft
in the burner resulted in faster gasification
rates and higher temperatures in the TLUD.
Besides riser height, I have found that a
number of design elements of the gas burner
can increase gasification rate such as the
size of secondary air holes.</div>
<div><br>
</div>
<div>I have a few more of these experimental
vignette to come, such as how creating a
vortex flame may not be a good idea, and how
heat is lost from the side walls of the
reactor, and a reasonable heap on reactor
temperature for different fuels. Now that
snow is on the ground in Southern Ontario, I
have more time to analyze data.</div>
<div><br>
</div>
<div>All the best</div>
<div>Julien<br clear="all">
<br>
-- <br>
</div>
<div>
<div dir="ltr">Julien Winter<br>
Cobourg, ON, CANADA<br>
</div>
</div>
</div>
</div>
</blockquote>
</div>
</div>
<blockquote type="cite">
<div><Height of gas burner riser.pdf></div>
</blockquote>
<blockquote type="cite">
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</blockquote>
</div>
</blockquote>
</div>
<br>
<br clear="all">
<br>
-- <br>
<div class="gmail_signature">
<div dir="ltr">Julien Winter<br>
Cobourg, ON, CANADA<br>
</div>
</div>
</div>
</blockquote>
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