<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML xmlns="http://www.w3.org/TR/REC-html40" xmlns:v =
"urn:schemas-microsoft-com:vml" xmlns:o =
"urn:schemas-microsoft-com:office:office" xmlns:w =
"urn:schemas-microsoft-com:office:word" xmlns:m =
"http://schemas.microsoft.com/office/2004/12/omml"><HEAD>
<META content="text/html; charset=iso-8859-1" http-equiv=Content-Type>
<META name=GENERATOR content="MSHTML 9.00.8112.16575">
<STYLE>@font-face {
font-family: SimSun;
}
@font-face {
font-family: SimSun;
}
@font-face {
font-family: Calibri;
}
@font-face {
font-family: @SimSun;
}
@page WordSection1 {size: 8.5in 11.0in; margin: 1.0in 1.0in 1.0in 1.0in; }
P.MsoNormal {
MARGIN: 0in 0in 0pt; FONT-FAMILY: "Calibri","sans-serif"; FONT-SIZE: 12pt
}
LI.MsoNormal {
MARGIN: 0in 0in 0pt; FONT-FAMILY: "Calibri","sans-serif"; FONT-SIZE: 12pt
}
DIV.MsoNormal {
MARGIN: 0in 0in 0pt; FONT-FAMILY: "Calibri","sans-serif"; FONT-SIZE: 12pt
}
A:link {
COLOR: blue; TEXT-DECORATION: underline; mso-style-priority: 99
}
SPAN.MsoHyperlink {
COLOR: blue; TEXT-DECORATION: underline; mso-style-priority: 99
}
A:visited {
COLOR: purple; TEXT-DECORATION: underline; mso-style-priority: 99
}
SPAN.MsoHyperlinkFollowed {
COLOR: purple; TEXT-DECORATION: underline; mso-style-priority: 99
}
SPAN.EmailStyle17 {
FONT-FAMILY: "Calibri","sans-serif"; COLOR: windowtext; mso-style-type: personal-compose
}
.MsoChpDefault {
FONT-FAMILY: "Calibri","sans-serif"; mso-style-type: export-only
}
DIV.WordSection1 {
page: WordSection1
}
</STYLE>
<!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]--></HEAD>
<BODY lang=EN-US bgColor=#ffffff vLink=purple link=blue>
<DIV><FONT size=2 face=Arial>
<DIV><FONT size=2 face=Arial>Huck,</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>I was not planning to venture an answer to you
question since it was addressed to Paul Anderson, but he answered and opened it
to the list so here goes.</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>Your question asks why the heat generated to drive
off the gasses from the fuel doesn't burn the charcoal in the Champion stove.
The reason is that there is not enough oxygen. It also doesn't burn most of the
wood gas. Only a small amount of primary air is allowed into the stove providing
enough oxygen to support the pyrolysis process to heat the fuel and continue
producing more wood gas, but not enough oxygen to support burning either the
char or most of the gas. Only a small amount of wood gas burns with the limited
primary air to keep the process going. The three components needed for a fire
are fuel, heat, and oxygen, and oxygen is limited here. Most of the gas, which
contains flamable hydrogen and carbonmonoxide rises. It is hot but mostly
unburned. Secondary air is injected into it above the char and that is where the
gas begins burning. Once all the volitiles are driven out of the fuel, then the
small amount of primary oxygen will start supporting the burning of the char,
producing both CO and CO2. The charcoal fire is adjustable with the primary
adjustment, so increasing the primary air increases the charcoal fire. If the
char is hot enough and there is adiquate oxygen from the secondary, there will
be a CO flame. It is bluish and very dim in a lighted area, but quite visible in
darkness. I do not know if this flame burns all of the CO forming CO2, or leaves
a lot of CO unburned. The charcoal fire can provide good heat for a time after
the hydrocarbon flame goes out. I have even brought a small amount of water to
boil using the charcoal fire. As the others have stated, the red hot charcoal is
very hot and damaging to the metal of the stove. </FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>The pyrolysis process is interesting as well. The
heated fuel produces wood gas. Most of this gas rises to the secondary burn
area, but a small amount of it is burned at the pyrolysis front using the
primary air. This small wood gas flame is what keeps heating the fuel and keeps
the process going. The mechanism by which the pyrolysis front moves down into
the fuel is mostly radiant heat. The small primary wood gas flame and hot char
will radiate heat downward to a piece of fuel, heating it. At some point the
temperature of this piece reaches the the flash point. At this point a very
small flame moves around the surface of the piece and chars the surface. This
tiny flame lasts maybe 2 seconds and then goes out and the piece is now
producing wood gas, a small amount of which is burned using the primary air,
thus continuing the process.</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>The making of charcoal from wood is a pyrolysis
process. The wood is put into a container which keeps oxygen out. Then some heat
source heats the container to the point where the volatiles are driven off. The
wood gas must have some way of exiting the container to avoid explosion. Without
oxygen, the charcoal does not burn. The gas is often vented to the
atmosphere where it cools and becomes smoke, a very wasteful process.</FONT>
<FONT size=2 face=Arial></FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>I like the idea of having a replaceable sacraficial
lining for the reactor so that the char can be burned in place if
desired.</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>Kirk</FONT></DIV></FONT></DIV>
<BLOCKQUOTE
style="BORDER-LEFT: #000000 2px solid; PADDING-LEFT: 5px; PADDING-RIGHT: 0px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px"
dir=ltr>
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="FONT: 10pt arial; BACKGROUND: #e4e4e4; font-color: black"><B>From:</B>
<A title=huckrorick@groundwork.org
href="mailto:huckrorick@groundwork.org">Huck Rorick</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=psanders@ilstu.edu
href="mailto:psanders@ilstu.edu">psanders@ilstu.edu</A> ; <A
title=stoves@lists.bioenergylists.org
href="mailto:stoves@lists.bioenergylists.org">stoves@lists.bioenergylists.org</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, October 14, 2014 9:36
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [Stoves] Why doesn't charcoal
burn in the Champion TLUD?</DIV>
<DIV><BR></DIV>
<DIV class=WordSection1>
<P class=MsoNormal>Hi Paul, <o:p></o:p></P>
<P class=MsoNormal><o:p> </o:p></P>
<P class=MsoNormal>Can you explain why the charcoal in a Champion TLUD doesn’t
burn? There is heat generated to drive off the gases from the
wood. Why doesn’t that heat burn the carbon as well?<o:p></o:p></P>
<P class=MsoNormal><o:p> </o:p></P>
<P class=MsoNormal>Under what circumstances would it burn?<o:p></o:p></P>
<P class=MsoNormal><o:p> </o:p></P>
<P class=MsoNormal>If you leave the charcoal in the bottom of the TLUD and
don’t dump it out into an airtight container will it slowly burn away in the
bottom of the TLUD? If you shut off the primary air? Will it burn
away quickly if you give maximum primary air?<o:p></o:p></P>
<P class=MsoNormal><o:p> </o:p></P>
<P class=MsoNormal>Huck<o:p></o:p></P>
<P style="mso-margin-top-alt: auto; mso-margin-bottom-alt: auto"
class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: #400040">Huck
Rorick</SPAN><SPAN
style="FONT-FAMILY: 'Times New Roman','serif'"><o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: gray">Executive
Director<BR>Groundwork Institute<BR>2640 Silvercrest Street<BR>Pinole, CA
94564<BR>Phone: 510-222-4111<BR>email: </SPAN><A
href="mailto:huckrorick@groundwork.org"><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: blue">huckrorick@groundwork.org</SPAN></A><SPAN
style="FONT-FAMILY: 'Times New Roman','serif'; COLOR: gray"><BR></SPAN><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: gray">Website:
</SPAN><U><SPAN style="FONT-FAMILY: 'Arial','sans-serif'; COLOR: blue"><A
href="http://www.groundwork.org"><SPAN
style="COLOR: blue">www.groundwork.org</SPAN></A></SPAN></U><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'"> </SPAN><SPAN
style="FONT-SIZE: 11pt"><o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN style="FONT-SIZE: 11pt"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt"><o:p> </o:p></SPAN></P></DIV>
<P>
<HR>
<P></P>_______________________________________________<BR>Stoves mailing
list<BR><BR>to Send a Message to the list, use the email
address<BR>stoves@lists.bioenergylists.org<BR><BR>to UNSUBSCRIBE or Change
your List Settings use the web
page<BR>http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org<BR><BR>for
more Biomass Cooking Stoves, News and Information see our web
site:<BR>http://stoves.bioenergylists.org/<BR><BR>
<P>
<HR>
<P></P><A></A>
<P align=left color="#000000" avgcert??>No virus found in this
message.<BR>Checked by AVG - <A
href="http://www.avg.com">www.avg.com</A><BR>Version: 2014.0.4765 / Virus
Database: 4040/8384 - Release Date: 10/13/14</P></BLOCKQUOTE></BODY></HTML>