<html 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" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=utf-8"><meta name=Generator content="Microsoft Word 14 (filtered medium)"><!--[if !mso]><style>v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style><![endif]--><style><!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p
{mso-style-priority:99;
margin:0cm;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
p.MsoAcetate, li.MsoAcetate, div.MsoAcetate
{mso-style-priority:99;
mso-style-link:"Balloon Text Char";
margin:0cm;
margin-bottom:.0001pt;
font-size:8.0pt;
font-family:"Tahoma","sans-serif";}
span.EmailStyle18
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
span.BalloonTextChar
{mso-style-name:"Balloon Text Char";
mso-style-priority:99;
mso-style-link:"Balloon Text";
font-family:"Tahoma","sans-serif";}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
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-ZA link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Greetings Ron and all,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>A very small percentage use preheated air, One I know heats to 300C. All about recycling heat, leading to lower fuel use.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Perhaps Crispin can give us an estimate on the excess air that gives 2% O2 in the flue gas.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I do not believe that the fuel plays such an important role. All about the 3 T’s. and allowing the flame to burn to completion. Obviously the size plays a very big role, The little furnaces in our stoves have a very large surface area in the combustion chamber relative to the heat generation. They also tend to have a short flame area, with little or no insulation. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>In reality we cannot emulate the industrial furnace, but we can learn from it.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> I do accept that biomass has a moisture content in the unburned gas, but we should look at industrial biomass furnaces for pointers, I believe that there a many in 1<sup>st</sup> world countries.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Keep up the good work,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>John.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> stoves-bounces@lists.bioenergylists.org [mailto:stoves-bounces@lists.bioenergylists.org] <b>On Behalf Of </b>rongretlarson@comcast.net<br><b>Sent:</b> 02 August 2011 12:02 AM<br><b>To:</b> Discussion of biomass cooking stoves<br><b>Subject:</b> Re: [Stoves] Secondary combustion.<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-family:"Arial","sans-serif";color:black'>John (cc list):<br><br> What percentage of these industrial gas furnaces that you deal with use preheating of the combustion air? <br><br>And<br><br> Is this a totally different question than when working with biomass and pyrolysis? (or coal/coke in SA?)<br><br>Ron<o:p></o:p></span></p><div class=MsoNormal align=center style='text-align:center'><span style='font-family:"Arial","sans-serif";color:black'><hr size=3 width="100%" align=center id=zwchr></span></div><p class=MsoNormal style='margin-bottom:12.0pt'><b><span style='font-family:"Arial","sans-serif";color:black'>From: </span></b><span style='font-family:"Arial","sans-serif";color:black'>"John Davies" <<a href="mailto:jmdavies@telkomsa.net">jmdavies@telkomsa.net</a>><br><b>To: </b>"Discussion of biomass cooking stoves" <<a href="mailto:stoves@lists.bioenergylists.org">stoves@lists.bioenergylists.org</a>><br><b>Sent: </b>Sunday, July 31, 2011 11:22:03 PM<br><b>Subject: </b>[Stoves] Secondary combustion.<br><br>Dear Tom and all.<br><br>I work with industrial gas furnaces,<br><br>Some use a mixture of gasses with H2, CO, CO2, CH4 with traces of C2's to<br>C4'4's. - with a HV as low as 16 MJ/m3. Others burn Natural gas with a HV<br>of 40 MJ/m3. Some have preheated air and some do not.<br><br>All run with a minimum of excess air, with about 1.5 to 2% O2 in the flue<br>gas and very low CO.<br><br><br><o:p></o:p></span></p></div></div></body></html>