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<div class="moz-cite-prefix">Stovers,<br>
<br>
I have left below the previous discussion by Ron and me. And I
thank him for his thoughtful comments. <br>
<br>
But to keep things short, here is a reply to some issues raised
(much snipped and with order sometimes changed:<br>
<br>
1. Ron wrote:
<blockquote type="cite"><b>I think the diffusion process is
substantially similar, in both normal and “inverted” flames. </b></blockquote>
<blockquote type="cite"><b>Are there other TLUD photos around I
can look at, that show the flame appearing between secondary
air holes - not over them?</b></blockquote>
Inverted flames are conical just like regular flames. Looking
downward at them, the parts that are over and below the air coming
in are the thinnest and the flame can appear to be absent. But
it certainly is there. Meanwhile, the parts of the flame on the
two sides of the cone are seen as much more yellow because of
looking downward through side-wall of the cone, which can appear
to be "thicker." AND, because the sidewall flames of two adjacent
inverted cones are close together, the flames are joined and
appear to be attached to the walls of the fuel canister. <br>
<br>
2. Paul A. Wrote: <br>
<blockquote type="cite"> In the TLUD gasifiers, the secondary air
holes are sufficiently close together that the inverted flames
are filling the space between the apertures of the incoming gas
(which is actually air).</blockquote>
I should have written ".... the incoming <i><u>NON-combustible</u></i>
gas (which is actually air). " Sorry for the confusion. The
INVERTED flame is still the mixing of two gases (air and
combustible gas), but with the air in the center of the cone.<br>
<br>
3. Alexis Belonio's most known stoves are with "natural flames"
with the combustible gases being injected vertically into a zone
of air, with his burners looking much like a regular burner of gas
fuel. But Alexis was discussing with me the inverted flame
situation, so my comment was correct when I wrote:
<blockquote type="cite">And also, Alexis Belonio was advocating in
January 2014 at the Aprovecho Open House about some form of
spreading the gases that need to reach the secondary air that is
coming in from the sides. </blockquote>
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 5/3/2014 2:34 PM, Ronal W. Larson wrote:<br>
</div>
<blockquote
cite="mid:09AAA328-165A-4C5F-BE07-3B33CA51AD2E@comcast.net"
type="cite">
<div>
<div>
<blockquote type="cite">
<div bgcolor="#FFFFFF" text="#000000">
<div class="moz-cite-prefix"> ***** change of topic
***********<br>
<br>
I comment on Ron's statement:
<blockquote type="cite">By looking closely,
counterintuitively, the flames seem attached NOT over
the gas apertures, but rather between them. I think
this is true in all cases but can’t see the case C
“attachment” points. Except in private dialogs with
Paul O, I have not seen this stated before in print -
and don’t know if it should be encouraged or
discouraged. <br>
</blockquote>
I think this has been considerably discussed or at least
observed. </div>
</div>
</blockquote>
<span class="Apple-tab-span" style="white-space:pre"> </span><b>[RWL:
If anyone can provide a link, that would be much
appreciated. Paul Olivier and I never found a write-up -
and it still baffles me. Are there other TLUD photos around
I can look at, that show the flame appearing between
secondary air holes - not over them?</b><br>
<blockquote type="cite">
<div bgcolor="#FFFFFF" text="#000000">
<div class="moz-cite-prefix"> It relates to the phenomenon
of the "inverted flame" in which the air enters a zone
of combustible gases instead of the combustible gases
entering a zone of air (which is the case of common gas
burners on stoves. </div>
</div>
</blockquote>
<span class="Apple-tab-span" style="white-space:pre"> </span><b>[RWL:
Well, I think there is another explanation. Paul Olivier
has his gas flamelets enter into air - not the "inverted
flame”, which I agree is or could be substantially
different. But the Olivier/Belonio flamelets (very short -
not the typical long flames of most TLUDs) look remarkably
similar to small match or candle flames. I think the
diffusion process is substantially similar, in both normal
and “inverted” flames. I think the results obtained by Jim
Jetter showing low particulates and CO with many TLUD tests
indicate the regular and inverted flames can’t be widely
different. The emissions are arguably superior with TLUDs -
and (maybe) independent of whether these flames seem to
originate from over or between holes.</b><br>
<blockquote type="cite">
<div bgcolor="#FFFFFF" text="#000000">
<div class="moz-cite-prefix"> In the TLUD gasifiers, the
secondary air holes are sufficiently close together that
the inverted flames are filling the space between the
apertures of the incoming gas (which is actually air).</div>
</div>
</blockquote>
<span class="Apple-tab-span" style="white-space:pre"> </span><b>[RWL:
As noted above, I mostly operated with a continuous
circumferential narrow slit - and never saw this - which is
why I used “counterintuitively” Has anyone ever seen this
with a natural gas multi-hole burner? My discussions with
Paul Olivier centered on the importance of radiation -
possibly coupled with the fact that pyrolysis gases have a
chemistry (not try for methane) which gives you a smaller
number of reaction particles at the end than going in.
Makes for a helpful pressure difference. (This holds for
whether there is gas entering air or air entering gas.)</b></div>
<div><b><span class="Apple-tab-span" style="white-space:pre"> </span>Re
the last clause <i>("which is actually air")</i> needs more
discussion. There has to be some gas there in order to have
a flame. If there were still eight input ports, but
appreciably smaller, would we see the same thing? Does it
have to do with a big air speed through the input ports?</b></div>
<div><b><span class="Apple-tab-span" style="white-space:pre"> </span>I
think there is a doctoral thesis lurking in here somewhere.
There may be some optimum of hole diameters, spacings,
shapes, separations, etc - to get the best flames
(better “flamelets”).</b></div>
<div><b><br>
</b></div>
<div><b>Ron<br>
</b>
<blockquote type="cite">
<div bgcolor="#FFFFFF" text="#000000">
<div class="moz-cite-prefix"> <span
class="Apple-tab-span" style="white-space:pre"> </span><br>
Paul A.<br>
<pre class="moz-signature" cols="72">Doc / Dr TLUD / Prof. Paul S. Anderson, PhD
Email: <a moz-do-not-send="true" class="moz-txt-link-abbreviated" href="mailto:psanders@ilstu.edu">psanders@ilstu.edu</a>
Skype: paultlud Phone: +1-309-452-7072
Website: <a moz-do-not-send="true" class="moz-txt-link-abbreviated" href="http://www.drtlud.com/">www.drtlud.com</a></pre>
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