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From Hugh McLaughlin to the Stoves Listserv (forwarded by Paul
Anderson)<br>
<div class="moz-forward-container"><br>
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<th nowrap="nowrap" valign="BASELINE" align="RIGHT">Subject:
</th>
<td>Re: [Stoves] Explaination of downdraft in TLUD updraft
stoves ---was --Re: Mis-information</td>
</tr>
<tr>
<th nowrap="nowrap" valign="BASELINE" align="RIGHT">Date: </th>
<td>Sat, 24 Mar 2018 16:23:27 +0000 (UTC)</td>
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<th nowrap="nowrap" valign="BASELINE" align="RIGHT">From: </th>
<td>Hugh McLaughlin <a class="moz-txt-link-rfc2396E" href="mailto:wastemin1@verizon.net"><wastemin1@verizon.net></a></td>
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<th nowrap="nowrap" valign="BASELINE" align="RIGHT">Reply-To:
</th>
<td>Hugh McLaughlin <a class="moz-txt-link-rfc2396E" href="mailto:wastemin1@verizon.net"><wastemin1@verizon.net></a></td>
</tr>
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<th nowrap="nowrap" valign="BASELINE" align="RIGHT">To: </th>
<td>Paul Anderson <a class="moz-txt-link-rfc2396E" href="mailto:psanders@ilstu.edu"><psanders@ilstu.edu></a>, Discussion of
biomass cooking stoves
<a class="moz-txt-link-rfc2396E" href="mailto:stoves@lists.bioenergylists.org"><stoves@lists.bioenergylists.org></a>,
<a class="moz-txt-link-abbreviated" href="mailto:gkharris316@comcast.net">gkharris316@comcast.net</a> <a class="moz-txt-link-rfc2396E" href="mailto:gkharris316@comcast.net"><gkharris316@comcast.net></a>,
Hugh McLaughlin <a class="moz-txt-link-rfc2396E" href="mailto:wastemin1@verizon.net"><wastemin1@verizon.net></a></td>
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font-family:verdana, helvetica, sans-serif;font-size:13px">
<div id="yui_3_16_0_ym19_1_1521905822538_10513">All,</div>
<div id="yui_3_16_0_ym19_1_1521905822538_11067"><br>
</div>
<div dir="ltr" id="yui_3_16_0_ym19_1_1521905822538_10557">The
World Stove is a TLUD - there is no central downward flow of
vapors, for two good reasons:</div>
<div dir="ltr" id="yui_3_16_0_ym19_1_1521905822538_10599"><br>
</div>
<div dir="ltr" id="yui_3_16_0_ym19_1_1521905822538_10739">Thermodynamics:
The proposed descending hot gases, oxygen-free, are proposed
to supply the necessary latent heat to convert the biomass to
char. That heat duty is estimated at 5% of the heat of
combustion (to heat the biomass to 400C and vaporize the wood
gas). Please don't cite the exotherm from the formation of the
graphene structures - they amount to about a 50C temperature
rise at best. One simply cannot get the necessary flow of
inert gas down the column of fuel to keep the carbonization
going - without diluting the wood gas to a energy density
below the level necessary to support combustion.</div>
<div dir="ltr" id="yui_3_16_0_ym19_1_1521905822538_11452"><br>
</div>
<div dir="ltr" id="yui_3_16_0_ym19_1_1521905822538_11453">Fluid
Dynamics: The density of a column of vapor inside the fuel
stack is less than the density of the column of vapors in the
annulus of the stove. In the absence of some overriding
pressure gradient, the vapors follow the path of least
density, with increased temperature resulting in decreased
density of the local vapor. If this phenomenon is dictating
flows, then the cold outside air is splitting and going to
both the primary air entrance and up the secondary air
pathway.</div>
<div dir="ltr" id="yui_3_16_0_ym19_1_1521905822538_18717"><br>
</div>
<div dir="ltr" id="yui_3_16_0_ym19_1_1521905822538_18718">World
Stove advocates, in the form of Nathaniel, there is a
Bernoulli effect
(<a class="moz-txt-link-freetext" href="https://en.wikipedia.org/wiki/Bernoulli's_principle">https://en.wikipedia.org/wiki/Bernoulli's_principle</a>).
Unfortunately, at any reasonable vapor flows for a tiny stove,
the Bernoulli effect is far below the magnitude necessary to
reverse the flow in the fuel stack from buoyancy-driven upflow
to postulated downflow.<br>
</div>
<div dir="ltr" id="yui_3_16_0_ym19_1_1521905822538_35945"><br>
</div>
<div dir="ltr" id="yui_3_16_0_ym19_1_1521905822538_35946">I
admire the attention Nathaniel has brought to the Stove
Community, but his claim of uniqueness from commonplace TLUD
technology is unsupported by the (cruel) science of the
situation. The utilization of forced draft does not materially
change the above analysis.<br>
</div>
<div dir="ltr" id="yui_3_16_0_ym19_1_1521905822538_46412"><br>
</div>
<div dir="ltr">Hugh McLaughlin, PhD, PE<br>
</div>
<div id="yui_3_16_0_ym19_1_1521905822538_10512"><span></span></div>
<div class="qtdSeparateBR"><br>
<br>
</div>
<div class="yahoo_quoted" style="display: block;">
<div style="font-family: verdana, helvetica, sans-serif;
font-size: 13px;">
<div style="font-family: HelveticaNeue, Helvetica Neue,
Helvetica, Arial, Lucida Grande, sans-serif; font-size:
16px;">
<div dir="ltr"><font size="2" face="Arial"> On Saturday,
March 24, 2018 9:34 AM, Paul Anderson
<a class="moz-txt-link-rfc2396E" href="mailto:psanders@ilstu.edu"><psanders@ilstu.edu></a> wrote:<br>
</font></div>
<br>
<br>
<div class="y_msg_container">
<div id="yiv4195693447">
<div> <br>
<pre class="yiv4195693447moz-signature">Doc / Dr TLUD / Prof. Paul S. Anderson, PhD
Email: <a rel="nofollow" class="yiv4195693447moz-txt-link-abbreviated" ymailto="mailto:psanders@ilstu.edu" target="_blank" href="mailto:psanders@ilstu.edu" moz-do-not-send="true">psanders@ilstu.edu</a>
Skype: paultlud Phone: +1-309-452-7072
Website: <a rel="nofollow" class="yiv4195693447moz-txt-link-abbreviated" target="_blank" href="http://www.drtlud.com/" moz-do-not-send="true">www.drtlud.com</a></pre>
<div class="yiv4195693447moz-cite-prefix">On
3/24/2018 7:39 AM, Ronal W. Larson wrote:<br>
</div>
<blockquote type="cite">
<div class="yiv4195693447">Kirk et al</div>
<div class="yiv4195693447"><br
class="yiv4195693447">
</div>
<div class="yiv4195693447"><span class="yiv4195693447Apple-tab-span" style="white-space:pre;"> </span>You
have it partially correct - but we are not
talking about a TLUD. There is no MPF (Moving
Pyrolysis Front). Rather, the pyrolysis gases
are created by the downward flowing (very) hot
gases.. <br>
</div>
</blockquote>
Incorrect. There is no way for the very hot gases
that are the flame at the top to go downward WITH O2
through a substantial layer of hot charcoal and then
reach the raw biomass fuel at temperatures that are
going to cause full-fledged pyrolysis (at least
above 400 C) and continue downward to exit through
what are called "primary air inlets" (but are
claimed to be outlets).<br>
<blockquote type="cite">
<div class="yiv4195693447"><br
class="yiv4195693447">
</div>
<div class="yiv4195693447"><span class="yiv4195693447Apple-tab-span" style="white-space:pre;"> </span>Besides
N2, there is a fair amount of CO2 - but no O2.
Much more gas comes out the bottom than enters
(all valuable pyrolysis gases) . Possible only
because of the Venturi effect - not iimportant
in TLUDs.</div>
<div class="yiv4195693447"><br
class="yiv4195693447">
</div>
<div class="yiv4195693447"><span class="yiv4195693447Apple-tab-span" style="white-space:pre;"> </span>See <a
rel="nofollow" target="_blank"
href="http://www.charcoalproject.org/2010/05/a-man-a-stove-a-mission/"
class="yiv4195693447" moz-do-not-send="true">http://www.charcoalproject.org/2010/05/a-man-a-stove-a-mission/</a>
.</div>
</blockquote>
My very quick look at this did not find speciic
content about proving the downdraft issue. (If
anyone finds specific content, please call it to
my/our attention.)<br>
<blockquote type="cite">
<div class="yiv4195693447"><br
class="yiv4195693447">
</div>
<div class="yiv4195693447">and:</div>
<div class="yiv4195693447"><br
class="yiv4195693447">
</div>
<div class="yiv4195693447"><a rel="nofollow"
target="_blank"
href="https://foodtank.com/news/2017/05/nathaniel-mulcahy-worldstove-talks-clean-cooking-stoves/"
class="yiv4195693447" moz-do-not-send="true">https://foodtank.com/news/2017/05/nathaniel-mulcahy-worldstove-talks-clean-cooking-stoves/</a></div>
</blockquote>
Also an Info item, not a science item. <br>
<blockquote type="cite">
<div class="yiv4195693447"><br
class="yiv4195693447">
</div>
<div class="yiv4195693447">and </div>
<div class="yiv4195693447"><br
class="yiv4195693447">
</div>
<div class="yiv4195693447"><span class="yiv4195693447Apple-tab-span" style="white-space:pre;"> </span><a
rel="nofollow" target="_blank"
href="https://www.youtube.com/watch?v=QsH_Gh-n2Mg"
class="yiv4195693447" moz-do-not-send="true">https://www.youtube.com/watch?v=QsH_Gh-n2Mg</a></div>
</blockquote>
This is the FORCED AIR Lucia stove and is not
relevent to the current conversation.<br>
<br>
See further down my reply to Noil (or was the Neil),
and Crispin and Kirk.<br>
<blockquote type="cite">
<div class="yiv4195693447"><br
class="yiv4195693447">
</div>
<div class="yiv4195693447"><span class="yiv4195693447Apple-tab-span" style="white-space:pre;"> </span>I
will look for more technical descriptions.
Note these above emphasize the biochar part of
cooking.</div>
<div class="yiv4195693447"><br
class="yiv4195693447">
</div>
<div class="yiv4195693447">Ron</div>
<div class="yiv4195693447"><br
class="yiv4195693447">
</div>
<br class="yiv4195693447">
<div>
<blockquote type="cite" class="yiv4195693447">
<div class="yiv4195693447">On Mar 24, 2018, at
1:52 AM, Kirk H. <<a rel="nofollow"
ymailto="mailto:gkharris316@comcast.net"
target="_blank"
href="mailto:gkharris316@comcast.net"
class="yiv4195693447"
moz-do-not-send="true">gkharris316@comcast.net</a>>
wrote:</div>
<br
class="yiv4195693447Apple-interchange-newline">
<div class="yiv4195693447">
<div class="yiv4195693447WordSection1"
style="font-family:Helvetica;font-size:18px;font-style:normal;font-weight:normal;letter-spacing:normal;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;">
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;" class="yiv4195693447">All,</div>
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;" class="yiv4195693447"> </div>
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;" class="yiv4195693447">I
like Noll’s remarks. If down-draft was
occurring the gasses would cool as they
pass through the unburned fuel and so
the vapors would condense and become
smoke. There would be lots of smoke
exiting the primary holes. This is not
happening in the video. Creosote would
soon coat the entire bottom and annulus
portions of the stove and clog the
primary air openings. Creosote may also
coat the unburned fuel and so restrict
the air flow. Also the unburned fuel
would get hotter and hotter and possibly
begin pyrolysing in mass.</div>
</div>
</div>
</blockquote>
</div>
</blockquote>
VERY good point. Something that can be studied via
observation without lots of expensive equipment.<br>
<blockquote type="cite">
<div>
<blockquote type="cite" class="yiv4195693447">
<div class="yiv4195693447">
<div class="yiv4195693447WordSection1"
style="font-family:Helvetica;font-size:18px;font-style:normal;font-weight:normal;letter-spacing:normal;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;">
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;" class="yiv4195693447"> </div>
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;" class="yiv4195693447">Paul’s
question about how air would get to the
MPF from above is unanswered. The air
would have to pass through the flame.
This may be possible because the flame
is a gas and gasses are permeable. But
as the air passes through the flame, the
oxygen would get used up so only
nitrogen would descend into the fuel and
the MPF would go out.</div>
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;" class="yiv4195693447"> </div>
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;" class="yiv4195693447">Crispin
remarks that it would have to be an air
restricted situation for down-draft to
occur and only around the edges. This
sounds true, and you would not get much
fire power in an air restricted
situation. And remember how TLUDs go
out when turned down too much? Would
whatever this is have the same problem?</div>
</div>
</div>
</blockquote>
</div>
</blockquote>
Yes, such a flow is to be considered. I visualize
it as a donut. Primary air upward through the donut
hole and then some pyrolytic gases downward as an
annulus (the sides of the donut. Also to be
studied.<br>
<blockquote type="cite">
<div>
<blockquote type="cite" class="yiv4195693447">
<div class="yiv4195693447">
<div class="yiv4195693447WordSection1"
style="font-family:Helvetica;font-size:18px;font-style:normal;font-weight:normal;letter-spacing:normal;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;">
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;" class="yiv4195693447"> </div>
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;" class="yiv4195693447">With
adequate primary air to keep the MPF
going, adequate secondary air, and an
open top the gasses inside would be
actively interacting with the outside
atmosphere. All the gases, including
near the edge of the chamber are hotter
than the atmosphere and subject to
rising via buoyancy, although perhaps at
different rates. <span
class="yiv4195693447Apple-converted-space"> </span></div>
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;" class="yiv4195693447"> </div>
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;" class="yiv4195693447">It is
unlikely that it is down-draft. <span
class="yiv4195693447Apple-converted-space">
<br>
</span></div>
</div>
</div>
</blockquote>
</div>
</blockquote>
CLARIFICATION: Downdraft has at least two
meanings. One can be the movement of gases, such
as some pyrolytic gases moving downward in the fuel
column (what we are discussing). The other is as in
a downdraft gasifier there the hot gases exit the
gasifier by going downward THROUGH the bottom layer
of red-hot (white hot) charcoal.<br>
<br>
So the wording could be It is unlikely that
it is down-draft [gasification] Which it is not
in this case. OR <span
class="yiv4195693447Apple-converted-space">It is
unlikely that [there] is down-draft [of some gases
within the column of fue.]. (which is what is
being discussed.) <br>
<br>
NOTE: This is te the most vigorous
TECHNICAL-BASED DISCUSSION on the Stoves Listserv
for quite some time. I like it!!<br>
<br>
Paul<br>
<span class="yiv4195693447Apple-converted-space">
</span></span>
<blockquote type="cite">
<div>
<blockquote type="cite" class="yiv4195693447">
<div class="yiv4195693447">
<div class="yiv4195693447WordSection1"
style="font-family:Helvetica;font-size:18px;font-style:normal;font-weight:normal;letter-spacing:normal;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;">
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;" class="yiv4195693447"> </div>
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;" class="yiv4195693447">Kirk
H.</div>
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;" class="yiv4195693447"> </div>
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;" class="yiv4195693447"> </div>
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;" class="yiv4195693447">Sent
from<span
class="yiv4195693447Apple-converted-space"> </span><a
rel="nofollow" target="_blank"
href="https://go.microsoft.com/fwlink/?LinkId=550986"
style="color:rgb(149, 79,
114);text-decoration:underline;"
class="yiv4195693447"
moz-do-not-send="true">Mail</a><span
class="yiv4195693447Apple-converted-space"> </span>for
Windows 10</div>
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;" class="yiv4195693447"> </div>
<div style="border-style:solid none
none;border-top-color:rgb(225, 225,
225);border-top-width:1pt;padding:3pt
0in 0in;" class="yiv4195693447">
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;border:none;padding:0in;"
class="yiv4195693447"><b
class="yiv4195693447">From:<span
class="yiv4195693447Apple-converted-space"> </span></b><a
rel="nofollow"
ymailto="mailto:psanders@ilstu.edu"
target="_blank"
href="mailto:psanders@ilstu.edu"
style="color:rgb(149, 79,
114);text-decoration:underline;"
class="yiv4195693447"
moz-do-not-send="true">Paul Anderson</a><br
class="yiv4195693447">
<b class="yiv4195693447">Sent:<span
class="yiv4195693447Apple-converted-space"> </span></b>Friday,
March 23, 2018 6:09 PM<br
class="yiv4195693447">
<b class="yiv4195693447">To:<span
class="yiv4195693447Apple-converted-space"> </span></b><a
rel="nofollow"
ymailto="mailto:wastemin1@verizon.net"
target="_blank"
href="mailto:wastemin1@verizon.net"
style="color:rgb(149, 79,
114);text-decoration:underline;"
class="yiv4195693447"
moz-do-not-send="true">Hugh
McLaughlin</a>;<span
class="yiv4195693447Apple-converted-space"> </span><a
rel="nofollow"
ymailto="mailto:Stoves@lists.bioenergylists.org"
target="_blank"
href="mailto:Stoves@lists.bioenergylists.org"
style="color:rgb(149, 79,
114);text-decoration:underline;"
class="yiv4195693447"
moz-do-not-send="true">Stoves and
biofuels network</a><br
class="yiv4195693447">
<b class="yiv4195693447">Subject:<span
class="yiv4195693447Apple-converted-space"> </span></b>Re: [Stoves]
Explaination of downdraft in TLUD
updraft stoves ---was --Re:
Mis-information</div>
</div>
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;" class="yiv4195693447"> </div>
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;" class="yiv4195693447">Hugh,<br
class="yiv4195693447">
<br class="yiv4195693447">
Thanks for the reply. I am forwarding
it to the Stoves Listserv. <span
class="yiv4195693447Apple-converted-space"> </span><br
class="yiv4195693447">
<br class="yiv4195693447">
The impact of the air being drawn in
(creating a draft onto the ignited
stick) should be able to be checked by
shielding the flame from the direct
draft.<br class="yiv4195693447">
<br class="yiv4195693447">
To all: How can we get copies of these
messages to Heath Putnam for his input?<br
class="yiv4195693447">
<br class="yiv4195693447">
Paul<br class="yiv4195693447">
<br class="yiv4195693447">
<br class="yiv4195693447">
</div>
<pre style="margin:0in 0in 0.0001pt;font-size:10pt;font-family:'Courier New';" class="yiv4195693447">Doc / Dr TLUD / Prof. Paul S. Anderson, PhD</pre>
<pre style="margin:0in 0in 0.0001pt;font-size:10pt;font-family:'Courier New';" class="yiv4195693447">Email: <a rel="nofollow" ymailto="mailto:psanders@ilstu.edu" target="_blank" href="mailto:psanders@ilstu.edu" style="color:rgb(149, 79, 114);text-decoration:underline;" class="yiv4195693447" moz-do-not-send="true">psanders@ilstu.edu</a></pre>
<pre style="margin:0in 0in 0.0001pt;font-size:10pt;font-family:'Courier New';" class="yiv4195693447">Skype: paultlud Phone: +1-309-452-7072</pre>
<pre style="margin:0in 0in 0.0001pt;font-size:10pt;font-family:'Courier New';" class="yiv4195693447">Website: <a rel="nofollow" target="_blank" href="http://www.drtlud.com/" style="color:rgb(149, 79, 114);text-decoration:underline;" class="yiv4195693447" moz-do-not-send="true">www.drtlud.com</a></pre>
<div class="yiv4195693447">
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;" class="yiv4195693447">On
3/22/2018 5:41 PM, Hugh McLaughlin
wrote:</div>
</div>
<blockquote
style="margin-top:5pt;margin-bottom:5pt;"
class="yiv4195693447">
<div class="yiv4195693447">
<div
id="yiv4195693447yui_3_16_0_ym19_1_1521756600094_10264"
class="yiv4195693447">
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;background-color:white;" class="yiv4195693447"><span
style="font-size:10pt;font-family:Verdana,
sans-serif;"
class="yiv4195693447">Paul,</span></div>
</div>
<div
id="yiv4195693447yui_3_16_0_ym19_1_1521756600094_10270"
class="yiv4195693447">
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;background-color:white;" class="yiv4195693447"><span
style="font-size:10pt;font-family:Verdana,
sans-serif;"
class="yiv4195693447"> </span></div>
</div>
<div
id="yiv4195693447yui_3_16_0_ym19_1_1521756600094_10389"
class="yiv4195693447">
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;background-color:white;" class="yiv4195693447"><span
style="font-size:10pt;font-family:Verdana,
sans-serif;"
class="yiv4195693447">I am
unconvinced. One of the comments
(the first - Arthur Noll)
provides an explanation - it is
the air being drawn into the
base (primary air inlets) that
stimulate the burning at the
bottom.</span></div>
</div>
<div
id="yiv4195693447yui_3_16_0_ym19_1_1521756600094_10542"
class="yiv4195693447">
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;background-color:white;" class="yiv4195693447"><span
style="font-size:10pt;font-family:Verdana,
sans-serif;"
class="yiv4195693447"> </span></div>
</div>
<div
id="yiv4195693447yui_3_16_0_ym19_1_1521756600094_10543"
class="yiv4195693447">
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;background-color:white;" class="yiv4195693447"><span
style="font-size:10pt;font-family:Verdana,
sans-serif;"
class="yiv4195693447">Hugh</span></div>
</div>
<div
id="yiv4195693447yui_3_16_0_ym19_1_1521756600094_10513"
class="yiv4195693447">
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;background-color:white;" class="yiv4195693447"><span
style="font-size:10pt;font-family:Verdana,
sans-serif;"
class="yiv4195693447"> </span></div>
</div>
<div
id="yiv4195693447yui_3_16_0_ym19_1_1521756600094_10514"
class="yiv4195693447">
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;background-color:white;" class="yiv4195693447"><span
style="font-size:10pt;font-family:Verdana,
sans-serif;"
class="yiv4195693447">Noll's
comment is copied below:</span></div>
</div>
<div
id="yiv4195693447yui_3_16_0_ym19_1_1521756600094_10390"
class="yiv4195693447">
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;background-color:white;" class="yiv4195693447"><span
style="font-size:10pt;font-family:Verdana,
sans-serif;"
class="yiv4195693447"> </span></div>
</div>
<div
id="yiv4195693447yui_3_16_0_ym19_1_1521756600094_10503"
class="yiv4195693447">
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;background-color:white;" class="yiv4195693447"><span
style="font-size:10pt;font-family:Verdana,
sans-serif;"
class="yiv4195693447">That is
interesting, but I'm not
convinced that pyrolysis
products are coming out of the
bottom. You don't see any smoke
coming out the bottom until you
put the flaming stick in there.
The stick could be producing
the smoke that hits the bottom
of the can, turns sideways and
joins the flow of air, much of
which is rising up the sides
between the containers, while
smaller amounts are going in to
the wood. If it were correct
that products of pyrolysis
were going down and then up, I
would expect to see a
significant amount of smoke
coming out the bottom and up the
sides all the time, not just
when the stick was put in. And
I would expect to see soot and
tar precipitating out on the
surfaces between the containers.
Pyrolysis produces a combination
of gases, smoke, soot and tar.
It is messy. I have built these
stoves and this area is always
clean, even after many burns,
just like what you have is
clean. I have always felt that
the smoke, tar and gas from the
pyrolosis was rising up, and the
preheated air coming out the
secondary air holes, going into
this mixture of flammable gas
and vapor, made the jets of
flame. I don't think it makes
any difference whether you have
a jet of air going into a mass
of flammable gas or if you have
a jet of flammable gas going
into a mass of air, both can
give you a jet of flame.<span
class="yiv4195693447Apple-converted-space"> </span>
</span></div>
</div>
<div class="yiv4195693447">
<div class="yiv4195693447MsoNormal"
style="margin:0in 0in
12pt;font-size:11pt;font-family:Calibri,
sans-serif;background-color:white;"><span
style="font-size:10pt;font-family:Verdana,
sans-serif;"
class="yiv4195693447"> </span></div>
</div>
<div class="yiv4195693447">
<div class="yiv4195693447">
<div class="yiv4195693447">
<div class="yiv4195693447">
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;background-color:white;" class="yiv4195693447"><span
style="font-size:10pt;font-family:Arial,
sans-serif;"
class="yiv4195693447">On
Thursday, March 22, 2018
9:05 AM, Paul Anderson<span
class="yiv4195693447Apple-converted-space"> </span><a rel="nofollow"
ymailto="mailto:psanders@ilstu.edu"
target="_blank"
href="mailto:psanders@ilstu.edu"
style="color:rgb(149,
79,
114);text-decoration:underline;"
class="yiv4195693447"
moz-do-not-send="true"><psanders@ilstu.edu></a><span
class="yiv4195693447Apple-converted-space"> </span>wrote:</span><span
style="font-size:12pt;font-family:Helvetica,
sans-serif;"
class="yiv4195693447">
</span></div>
</div>
<div
class="yiv4195693447MsoNormal"
style="margin:0in 0in
12pt;font-size:11pt;font-family:Calibri,
sans-serif;background-color:white;"><span
style="font-size:12pt;font-family:Helvetica,
sans-serif;"
class="yiv4195693447"> </span></div>
<div class="yiv4195693447">
<div id="yiv4195693447"
class="yiv4195693447">
<div class="yiv4195693447">
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;text-align:center;background-color:white;"
class="yiv4195693447"><b
class="yiv4195693447"><span
style="font-size:14pt;font-family:Helvetica, sans-serif;"
class="yiv4195693447">Explanation
of downdraft in the
fuel chamber of TLUD
(UP draft) stoves.</span></b><span
style="font-size:12pt;font-family:Helvetica, sans-serif;"
class="yiv4195693447">
</span></div>
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;text-align:center;background-color:white;"
class="yiv4195693447"><span
style="font-size:12pt;font-family:Helvetica, sans-serif;"
class="yiv4195693447">Paul
S. Anderson, PhD
21 March 2018
</span></div>
<div class="yiv4195693447">
<div style="margin:0in
0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;background-color:white;" class="yiv4195693447"><span
style="font-size:12pt;font-family:Helvetica,
sans-serif;"
class="yiv4195693447">Stovers,
Previously I wrote:<br
class="yiv4195693447">
*******************<br
class="yiv4195693447">
This link takes you
to [what I am
calling Video A.)<br
class="yiv4195693447">
<a rel="nofollow"
target="_blank"
href="https://www.youtube.com/watch?annotation_id=annotation_1962734105&feature=iv&src_vid=wzN-cYR84_Y&v=b0vM9aD78XY"
style="color:rgb(149, 79, 114);text-decoration:underline;"
class="yiv4195693447"
moz-do-not-send="true">https://www.youtube.com/watch?annotation_id=annotation_1962734105&feature=iv&src_vid=wzN-cYR84_Y&v=b0vM9aD78XY</a><br
class="yiv4195693447">
Same fellow. and
showing clearly
UPdraft. Side by
side comparisons.
Well worth
watching. <span
class="yiv4195693447Apple-converted-space"> </span><br
class="yiv4195693447">
That is dated 2015.
I hope that somebody
will delve into this
further.</span></div>
</div>
<div class="yiv4195693447">
<div style="margin:0in
0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;background-color:white;" class="yiv4195693447"><span
style="font-size:12pt;font-family:Helvetica,
sans-serif;"
class="yiv4195693447">*****************************
</span></div>
</div>
<div class="yiv4195693447">
<div style="margin:0in
0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;background-color:white;" class="yiv4195693447"><span
style="font-size:12pt;font-family:Helvetica,
sans-serif;"
class="yiv4195693447"> First,
we all should thank
Heath Putnam for his
research and for
reporting it
publicly. He also
provided an earlier
video that lh cheng
saw and called to
our attention:<br
class="yiv4195693447">
<span
class="yiv4195693447Apple-converted-space"> </span><a
rel="nofollow"
target="_blank"
href="https://www.youtube.com/watch?v=wzN-cYR84_Y"
style="color:rgb(149, 79, 114);text-decoration:underline;"
class="yiv4195693447"
moz-do-not-send="true">https://www.youtube.com/watch?v=wzN-cYR84_Y</a> <span
class="yiv4195693447Apple-converted-space"> </span>
</span></div>
</div>
<div
style="margin-bottom:12pt;"
class="yiv4195693447">
<div style="margin:0in
0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;background-color:white;" class="yiv4195693447"><span
style="font-size:12pt;font-family:Helvetica,
sans-serif;"
class="yiv4195693447">This
I am calling Video
B. Although dated
earlier, it is
better to watch
Video A first.<br
class="yiv4195693447">
<br
class="yiv4195693447">
After sleeping on
this question last
night, I think I
have an
explanation. And
it also would
explain what Nate
Mulcahey presented
as the "Everything
Nice Stove" which he
claimed was not a
TLUD stove and
claimed to be a
downdraft flow of
the pyrolytic gases
(or Opposite
draft). Putnam's
work shows (but does
not explain) the
answers about
downdraft in updraft
TLUD stoves. <span
class="yiv4195693447Apple-converted-space"> </span><br
class="yiv4195693447">
<br
class="yiv4195693447">
The big clue
(revealed in video
(A) above) is the
difference between
the two trial
units. The
difference is a
sealed bottom that
enables a
"co-mingled air
supply zone" for
somewhat restricted
primary and
secondary air versus
abundant secondary
air that arrives
separately from the
supply of primary
air. <span
class="yiv4195693447Apple-converted-space"> </span><br
class="yiv4195693447">
<br
class="yiv4195693447">
If the primary air
entry is direct or
very nearly direct
and sufficient even
with a small,
restricted flow, it
will sustain the
migratory pyrolytic
front (MPF), and all
the air and gases
will flow upward.
This is the CLASSIC
description of TLUD
operation.<br
class="yiv4195693447">
<br
class="yiv4195693447">
But consider the
case of a
TLUD-design stove
that has a closed
bottom (or is
sitting reasonably
tightly on a flat
surface that
prevents entry of
abundant air) AND
also has somewhat
limited entry (via 4
holes in Putnam's
glass outer
cylinder) of air for<span
class="yiv4195693447Apple-converted-space"> </span><b
class="yiv4195693447"><u
class="yiv4195693447">BOTH<span
class="yiv4195693447Apple-converted-space"> </span></u></b>primary
and secondary air
into a space (a
"co-mingled air
supply zone") from
which BOTH types of
air must be drawn.
Therefore, the only
exit is upward. The
only DRAFT for the
stove is powered by
the flame of the
burning gases at the
top. <span
class="yiv4195693447Apple-converted-space"> </span><br
class="yiv4195693447">
<br
class="yiv4195693447">
Consider the case of
a functioning TLUD
stove when the MPF
is below a layer of
charcoal about 3 to
6 cm down from the
top, with another 7
to 12 cm of raw fuel
below the MPF. The
pyrolysis occurs,
and the hot gases
tend to rise upward
through the layer of
char and into the
zone of the cooking
flame. But the
flame requires
secondary air, which
can only come up in
the ring (annulus)
between the two
cylinders, and it
does come up. This
is the vast majority
of the total supply
of air (about 5
units for secondary
to 1 unit of primary
air). In fact,
that natural draft
by the flame is
pulling the air from
the "co-mingled air
supply zone" (that
one place of air
supply which is also
feeding the primary
air). There is
therefore a
reduction of air
pressure below the
MPF, and that means
less movement of the
primary air
upwards. <span
class="yiv4195693447Apple-converted-space"> </span><br
class="yiv4195693447">
<br
class="yiv4195693447">
The result is that
there is sufficient
lower pressure that
SOME of the
pyrolytic gases move
downward. Probably
some swirling also,
or some channels of
gases going down but
with SOME (at least
some) primary air
(the O2 is the
important part)
moving to the MPF. <span
class="yiv4195693447Apple-converted-space"> </span><br
class="yiv4195693447">
With a little bit of
time, some of the
pyrolytic gases
reach the entry
holes of the primary
air and leak outward
into the "co-mingled
air supply zone"
where there is fresh
air entering and
where those gases
can be combusted (as
shown in the Putnam
demonstration in
Video B).
Impressive. And if
there is no flame
down there, those
pyrolytic gases can
be pulled upward to
become part of the
upward flowing
secondary air THAT
IS NOW PRE-MIXED
(-but rather diluted
to some unknown
amount -) WITH
COMBUSTIBLE GASES.
Nice trick, and you
can see Putnam's
demonstration of a
taller, stronger
flame (Video A).
This is important.
Pre-mixing is to be
encouraged. But it
should be understood
and done
intentionally to
attain consistent
results. <span
class="yiv4195693447Apple-converted-space"> </span><br
class="yiv4195693447">
<br
class="yiv4195693447">
BUT in the described
simple setup,
production of the
pyrolytic gases is
suffering. There
is a somewhat
deficiency of
primary air. That
could be forgiven
(or overlooked or
ignored) except for
one very important
factor:<br
class="yiv4195693447">
<br
class="yiv4195693447">
When the downdraft
is occurring, the
stove user loses
some control over
the fire. The
draft from the
burning gases is now
regulating (in part)
the operations of
the TLUD stove. The
normal control of a
TLUD fire is by
closing off some
primary air, or
using a small fan,
but these are no
longer as effective
because of the
co-mingled air. As
the flame at the top
changes when there
is downward flow
(shown by Putnam),
there is a ripple
effect to the air
flows. Adjust,
then adjust again,
and then adjust
again. <span
class="yiv4195693447Apple-converted-space"> </span><br
class="yiv4195693447">
<br
class="yiv4195693447">
You can look at the
Champion TLUD (only
one hole for primary
air entry) or the
Quad or the Troika
(by Awamu) with only
one entry for
primary air, or some
of the other more
established true
TLUD stoves. The
Peko Pe by Wendelbo
also keeps the two
air sources
separate.
Then look at
Putnam's variation
and at the
Everything Nice
stove and see how
the primary and
secondary air are
comingled and
subjected to the
draft created at
the top of the
stove.<br
class="yiv4195693447">
<br
class="yiv4195693447">
Also consider what
would happen if
there actually was
sufficient downward
draft for the FULL
reversal of the air
flow in the fuel
chamber. At the
top there is
flame. And how is
there any O2
surviving in that
flame so that it
could go downward
enough to go through
the 3 to 6 (and
deeper) layer of hot
charcoal in order
for O2 to reach FROM
ABOVE the top side
of the MPF and to
sustain that MPF for
sending gases
further downward?
And then those
pyrolytic gases
would need to go out
through what were
the primary air
inlet holes, and
then be mixed with
secondary air (but
never catching fire
because somehow
there was not a
spark there, even at
the end of the batch
with red-glowing
coals????), and then
rising in the
annulus between the
two cylinders, and
only when entering
the area of the main
flame would those
gases combust. But
this supposition of
FULL reversal of the
air flow is
impossible because
there are no
pyrolytic gases
moving upward from
the MPF. <span
class="yiv4195693447Apple-converted-space"> </span>
</span></div>
</div>
<div
style="margin-bottom:12pt;"
class="yiv4195693447">
<div style="margin:0in
0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;background-color:white;" class="yiv4195693447"><span
style="font-size:12pt;font-family:Helvetica,
sans-serif;"
class="yiv4195693447">Conclusion:
In a TLUD stove,
there can be PARTIAL
downward drafting of
the created
pyrolytic gases when
caused by natural
draft of secondary
air to counteract
the flow of primary
air. This is
educational, but
what is possible is
not necessarily
desirable or
practical. <span
class="yiv4195693447Apple-converted-space"> </span><br
class="yiv4195693447">
--<span
class="yiv4195693447Apple-converted-space"> </span><br
class="yiv4195693447">
Doc / Dr TLUD /
Prof. Paul S.
Anderson, PhD<br
class="yiv4195693447">
Email: <span
class="yiv4195693447Apple-converted-space"> </span><a
rel="nofollow"
ymailto="mailto:psanders@ilstu.edu"
target="_blank"
href="mailto:psanders@ilstu.edu"
style="color:rgb(149, 79, 114);text-decoration:underline;"
class="yiv4195693447"
moz-do-not-send="true">psanders@ilstu.edu</a><u class="yiv4195693447"><span
style="color:blue;" class="yiv4195693447"> <span
class="yiv4195693447Apple-converted-space"> </span></span></u>Skype:
paultlud Phone:<span
class="yiv4195693447Apple-converted-space"> </span><span
class="yiv4195693447MsoHyperlink"
style="color:blue;text-decoration:underline;">+1-309-452-7072</span><u
class="yiv4195693447"><span
style="color:blue;" class="yiv4195693447"> <span
class="yiv4195693447Apple-converted-space"> </span></span></u>Website: <span
class="yiv4195693447Apple-converted-space"> </span><a rel="nofollow"
target="_blank"
href="http://www.drtlud.com/"
style="color:rgb(149, 79, 114);text-decoration:underline;"
class="yiv4195693447"
moz-do-not-send="true">www.drtlud.com</a>
</span></div>
</div>
<div class="yiv4195693447">
<div
class="yiv4195693447">
<div
class="yiv4195693447">
<div
style="margin-bottom:12pt;"
class="yiv4195693447">
<div
style="margin:0in
0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;background-color:white;" class="yiv4195693447"><span
style="font-size:12pt;font-family:Helvetica,
sans-serif;"
class="yiv4195693447">
</span></div>
</div>
</div>
</div>
</div>
</div>
</div>
<div
class="yiv4195693447MsoNormal"
style="margin:0in 0in
12pt;font-size:11pt;font-family:Calibri,
sans-serif;background-color:white;"><span
style="font-size:12pt;font-family:Helvetica,
sans-serif;"
class="yiv4195693447"> </span></div>
</div>
</div>
</div>
</div>
</div>
</blockquote>
<div style="margin:0in 0in
0.0001pt;font-size:11pt;font-family:Calibri,
sans-serif;" class="yiv4195693447"> </div>
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class="yiv4195693447">
<span
style="font-family:Helvetica;font-size:18px;font-style:normal;font-weight:normal;letter-spacing:normal;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;float:none;display:inline;"
class="yiv4195693447">to UNSUBSCRIBE or
Change your List Settings use the web page</span><br
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<a rel="nofollow" target="_blank"
href="http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org"
style="color:rgb(149, 79,
114);text-decoration:underline;font-family:Helvetica;font-size:18px;font-style:normal;font-weight:normal;letter-spacing:normal;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;"
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moz-do-not-send="true">http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org</a><br
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<br
style="font-family:Helvetica;font-size:18px;font-style:normal;font-weight:normal;letter-spacing:normal;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;"
class="yiv4195693447">
<span
style="font-family:Helvetica;font-size:18px;font-style:normal;font-weight:normal;letter-spacing:normal;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;float:none;display:inline;"
class="yiv4195693447">for more Biomass
Cooking Stoves, News and Information see
our web site:</span><br
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<pre>_______________________________________________
Stoves mailing list
to Send a Message to the list, use the email address
<a rel="nofollow" class="yiv4195693447moz-txt-link-abbreviated" ymailto="mailto:stoves@lists.bioenergylists.org" target="_blank" href="mailto:stoves@lists.bioenergylists.org" moz-do-not-send="true">stoves@lists.bioenergylists.org</a>
to UNSUBSCRIBE or Change your List Settings use the web page
<a rel="nofollow" class="yiv4195693447moz-txt-link-freetext" target="_blank" href="http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org" moz-do-not-send="true">http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org</a>
for more Biomass Cooking Stoves, News and Information see our web site:
<a rel="nofollow" class="yiv4195693447moz-txt-link-freetext" target="_blank" href="http://stoves.bioenergylists.org/" moz-do-not-send="true">http://stoves.bioenergylists.org/</a>
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