<!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=utf-8" http-equiv=Content-Type>
<META name=GENERATOR content="MSHTML 8.00.6001.23501">
<STYLE>@font-face {
font-family: Cambria Math;
}
@font-face {
font-family: Calibri;
}
@page WordSection1 {size: 612.0pt 792.0pt; margin: 72.0pt 72.0pt 72.0pt 72.0pt; }
P.MsoNormal {
MARGIN: 0mm 0mm 0pt; FONT-FAMILY: "Times New Roman","serif"; FONT-SIZE: 12pt
}
LI.MsoNormal {
MARGIN: 0mm 0mm 0pt; FONT-FAMILY: "Times New Roman","serif"; FONT-SIZE: 12pt
}
DIV.MsoNormal {
MARGIN: 0mm 0mm 0pt; FONT-FAMILY: "Times New Roman","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
}
P {
FONT-FAMILY: "Times New Roman","serif"; MARGIN-LEFT: 0mm; FONT-SIZE: 12pt; MARGIN-RIGHT: 0mm; mso-style-priority: 99; mso-margin-top-alt: auto; mso-margin-bottom-alt: auto
}
SPAN.EmailStyle18 {
FONT-FAMILY: "Calibri","sans-serif"; COLOR: #1f497d; mso-style-type: personal-reply
}
.MsoChpDefault {
FONT-SIZE: 10pt; 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-CA link=blue bgColor=white vLink=purple>
<DIV><FONT face=Arial>Dear Crispin</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>Thanks very much for your helpful comments. </FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>Clearly, a chimney that vents products of combustion
outside the Living Space is advantageous, compared to a stove system that vents
into the Living Space. </FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>I was aware of the great importance of the size of the
Particulate Matter. Basically, "big dirt particles" are not nearly as bad as are
fine particles that can lodge deep in the lungs. Clearly also, "more bad-sized
particles", with "bad type composition", are worse than fewer "safer sized
particles", of "relatively neutral composition.</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>The only way to "digitize the generalities" is with a
scientifically sound test program that identifies and then measures the relevant
parameters. Once numbers have been attached to the relevant parameters, then it
is relatively easy to determine whether or not a given stove system is "safe" or
"hazardous."</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>Rice Hulls are very interesting. While they have a high
percentage of highly siliceous ash, complete combustion could potentially make
the ash available in a hazardous manner. In Paul O's case, where he is
interested in char making, I would guess that most of the siliceous components
would remain embedded within the char particles, in a safe and non-hazardous
manner. However, some ash particles would be liberated in that some of the char
would be burned in the pyrolysis process. </FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>Best wishes,</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>Kevin</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV>----- Original Message ----- </DIV>
<BLOCKQUOTE
style="BORDER-LEFT: #000000 2px solid; PADDING-LEFT: 5px; PADDING-RIGHT: 0px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px">
<DIV
style="FONT: 10pt arial; BACKGROUND: #e4e4e4; font-color: black"><B>From:</B>
<A title=crispinpigott@gmail.com href="mailto:crispinpigott@gmail.com">Crispin
Pemberton-Pigott</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=stoves@lists.bioenergylists.org
href="mailto:stoves@lists.bioenergylists.org">'Discussion of biomass cooking
stoves'</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, June 14, 2013 10:51
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [Stoves] Insulation and
stove life</DIV>
<DIV><BR></DIV>
<DIV class=WordSection1>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt; mso-fareast-language: EN-US">Dear
Kevin<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt; mso-fareast-language: EN-US"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt; mso-fareast-language: EN-US">I
would like to add that using a fan will in all likelihood create much more
flyash than without one. The advantage of a chimney is that the tends to suck
the ash up the chimney, whereas a fan tends to blow it up from below into
whatever outlet it can find. The difference in the room will be large,
obviously.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt; mso-fareast-language: EN-US"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt; mso-fareast-language: EN-US">Secondly
the size of the PM matters a lot. If the pyrolysis process releases very fine
siliceous matter with a gentle push from a fan, that material can easily rise
through the fuel bed.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt; mso-fareast-language: EN-US"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt; mso-fareast-language: EN-US">So
we should be investigating size, total mass, chemical composition and whether
the stove draws it from the stove and room or pushes it up from
below.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt; mso-fareast-language: EN-US"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt; mso-fareast-language: EN-US">Maybe
it is of no consequence at all, maybe it is a hazard.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt; mso-fareast-language: EN-US"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt; mso-fareast-language: EN-US">Regards<BR>Crispin<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt; mso-fareast-language: EN-US"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt; mso-fareast-language: EN-US"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><o:p> </o:p></P>
<DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'Arial','sans-serif'">Dear
Rebecca</SPAN><o:p></o:p></P></DIV>
<DIV>
<P class=MsoNormal> <o:p></o:p></P></DIV>
<DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'Arial','sans-serif'">Firstly, I
am concerned about the "Cristobalite Link" below, in that it seems to overlap
"silica", "cristobalite", and other forms of quartz. See: <A
href="http://www.quartzpage.de/gen_mod.html">http://www.quartzpage.de/gen_mod.html</A> showing
how various forms of quartz exist at various
temperatures.</SPAN><o:p></o:p></P></DIV>
<DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'Arial','sans-serif'">Note that
"cristobalite" is one specific crystalline phase of
quartz.</SPAN><o:p></o:p></P></DIV>
<DIV>
<P class=MsoNormal> <o:p></o:p></P></DIV>
<DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'Arial','sans-serif'">Secondly,
what is important is the "respirable" dust that is actually respired.
</SPAN><o:p></o:p></P></DIV>
<DIV>
<P class=MsoNormal> <o:p></o:p></P></DIV>
<DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'Arial','sans-serif'">It is well
known that respiring "silica dust" can cause "Silicosis". It is well known
that "Small Particulate Matter emissions" from virtually any poor stove can
cause serious health problems. Hence, the effort to design "stove systems"
that minimize "Small Particulate Matter Emissions" into the living space,
where they can potentially be respired.</SPAN><o:p></o:p></P></DIV>
<DIV>
<P class=MsoNormal> <o:p></o:p></P></DIV>
<DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'Arial','sans-serif'">Rice Hull
Ash, even at 90% silica in the ash pit, is not a problem, in that it is in the
ash pit, where it is not respired. On the other hand, an "apparently superior
fuel" that only had say 25% silica content in the ash pit would be vastly more
hazardous, if it vented 10 or 100 times as much ash into the living space, in
respirable form.</SPAN><o:p></o:p></P></DIV>
<DIV>
<P class=MsoNormal> <o:p></o:p></P></DIV>
<DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'Arial','sans-serif'">This is
where competent and meaningful stove design and testing comes into play.
</SPAN><o:p></o:p></P></DIV>
<DIV>
<P class=MsoNormal> <o:p></o:p></P></DIV>
<DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'Arial','sans-serif'">As has been
said many times, "It is not so much the fuel, but the stove system design,
that is good or bad."</SPAN><o:p></o:p></P></DIV>
<DIV>
<P class=MsoNormal> <o:p></o:p></P></DIV>
<DIV>
<P class=MsoNormal><SPAN style="FONT-FAMILY: 'Arial','sans-serif'">Best
wishes,</SPAN><o:p></o:p></P></DIV>
<DIV>
<P class=MsoNormal> <o:p></o:p></P></DIV>
<DIV>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Arial','sans-serif'">Kevin</SPAN><o:p></o:p></P></DIV>
<DIV>
<P class=MsoNormal> <o:p></o:p></P></DIV></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></BLOCKQUOTE></BODY></HTML>