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</o:shapelayout></xml><![endif]--></head><body bgcolor=white lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Stovers and Paul Anderson, <o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Since good char burns with little smoke it seems there could be some design improvements from the stove in Paul’s attachment:<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></b></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><span style='mso-list:Ignore'>1)<span style='font:7.0pt "Times New Roman"'> </span></span></span></b><![endif]><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>We can use shinny surfaces, perhaps like a bowl under the charcoal, to reflect the heat up to the pot.<o:p></o:p></span></b></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><span style='mso-list:Ignore'>2)<span style='font:7.0pt "Times New Roman"'> </span></span></span></b><![endif]><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Best to heat a pot we need a blast of hot air directed at the pot -that is not available with radiant heat. I believe to get char to burn we need the same; a blast of air directed at the char. Perhaps because when the carbon goes to CO or CO2 it releases enough heat to start another reaction IF there is oxygen stuck to that carbon allowing a reaction to take place. If not the heat dissipates and does little. <o:p></o:p></span></b></p><p class=MsoListParagraph><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></b></p><p class=MsoListParagraph><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Wondering: if a basket of char fitted with a plate at the bottom set on a spring pressing char up against a top grate. The container sealed such that primary air being drawn is directed through a pipe blasting 2cm from the top of the char bed (vertical pipe through the center of the char). The reflective surface directing heat produced to the pot. Something like that?<o:p></o:p></span></b></p><p class=MsoListParagraph><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></b></p><p class=MsoListParagraph><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Also; For char stoves is there ever a secondary? <o:p></o:p></span></b></p><p class=MsoListParagraph><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Thanks<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Frank<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></b></p><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif";color:#1F497D'>Frank Shields<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif";color:#1F497D'>Control Laboratories; Inc.<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif";color:#1F497D'>42 Hangar Way<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif";color:#1F497D'>Watsonville, CA 95076<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif";color:#1F497D'>(831) 724-5422 tel<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif";color:#1F497D'>(831) 724-3188 fax<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif";color:#1F497D'>frank@biocharlab.com<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-family:"Calibri","sans-serif";color:#1F497D'>www.controllabs.com<o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></b></p><p class=MsoNormal><b><span style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></b></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'> Stoves [mailto:stoves-bounces@lists.bioenergylists.org] <b>On Behalf Of </b>Paul Anderson<br><b>Sent:</b> Monday, September 16, 2013 7:24 AM<br><b>To:</b> Discussion of biomass cooking stoves; James S. Schoner<br><b>Subject:</b> [Stoves] Amount of charcoal for simmering<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Stovers, (this will also be a "post" at my <a href="http://www.drtlud.com">www.drtlud.com</a> website, BUT all replies and discussions should be directed via the Stoves Listserv. Dr TLUD does NOT carry on separate discussions via comments to his website.)<br><br>I am looking for a calculated answer that could give guidelines about the sizes of charcoal-burning stoves, referring to how much charcoal must be consumed for the cooking tasks.<br><br>Question: How much charcoal is needed (per minute, or per hour, or ??) to maintain a pot (5 liters?) of already-boiling water at the simmer temperature of about 96 deg C?<br><br>So many variables, but the replies can state whatever "givens" or assumptions you wish to make, such as:<br><br>1. Heat transfer efficiency of the stove-pot configuration: Is 30% about typical? And does that vary between clay-mud charcoal stoves vs metal charcoal stoves? Please specify, if your response takes that into account.<br><br>Reference: See <a href="http://search.mywebsearch.com/mywebsearch/redirect.jhtml?searchfor=heat+transfer+efficiency+charcoal+stoves&cb=XQ&p2=%5EXQ%5Exdm002%5ES03729%5Eus&qid=499b92ca6697461da7047b820086bd7d&n=77DE8857&ptb=F7EBB78D-F7A7-4077-B858-0D10F0C7CB0E&si=COjP4cCp0rMCFao7MgodRQUALQ&pg=GGmain&action=pick&ss=sub&pn=1&st=hp&qs=&pr=GG&tpr=hpsb&redirect=mPWsrdz9heamc8iHEhldEVRIIbml7k2%2FvmB8U5crkZmbOTdLROAzdl%2F4ZQYYskvUwjkty6%2BVZ%2BNQiIr863cMN8jdRHpxuJvwsN2u6HPpdnPNB%2BBymTTjJMbwcgCi5H8Q&ord=1&ct=AR&" target="_blank">Experimental study for improving energy <b>efficiency</b> of <b>charcoal stove</b> </a><br><a href="http://nopr.niscair.res.in/bitstream/123456789/3794/1/JSIR%2068(5)%20412-416.pdf">http://nopr.niscair.res.in/bitstream/123456789/3794/1/JSIR%2068(5)%20412-416.pdf</a><br>with reported efficiencies between 21% and 62%.<br><br>2. Still air, no wind.<br><br>3. Comments on types of pots (Stainless vs aluminum vs other).<br><br>4. Lid or no lid. Probably no lid because so much testing is done with no lid on pot.<br><br>5. Ambient temperature: probably 22 to 27 deg C.<br><br>6. Any other variables.?<br><br>Comments: The question arises because the TLUD stoves (and any other charcoal producing stoves) can be a convenient and low cost source of charcoal for a household. That household has some cooking needs for LOW heat (simmer-type), and a charcoal-burning stove.<br><br>Example from the world of stove testing: a pot with 5 liters brought to boil can be placed onto a charcoal stove for the remaining 45 minutes of the standard water boiling test (WBT). The charcoal could be already red-hot, having been placed in the charcoal stove directly from the TLUD stove that made the charcoal. How much charcoal is needed for that simmering task?<br><br>When we know the amount of charcoal, we can calculate backwards to determine how much raw fuel was needed to make that charcoal. (That amount of raw fuel is approximately 5 X of the charcoal weight.) Example: 100 g of char is produced from 500 g of woody biomass. <br><br>Therefore, about 70% of the energy content of the raw fuel would be available for INITIALLY putting heat into the pot. I think we should assume better than 40% heat transfer efficiency because that is the target for Tier 4 stoves and can be achieved by gas-burning stoves. 40% of 70% is 28%, so round it to 30%. And 30% of the energy content of the raw fuel is how much? 1 kg of wood has 16 MJ, so 500 g has 8 MJ, and 30% would be 2.4 MJ. <br><br>Somebody please complete the calculations: <br><br>A. 2.4 MJ will raise 5 liters (5000 g or ml) of water how many degrees?<br><br>B. How many g or ml of water can be brought to 100 C if starting temp of water is 20 C?<br><br>In the end, I hope we have some understanding about the amount of raw fuel and resultant charcoal needed to accomplish the WBT with minimal waste.<br><br>Paul<br><br><o:p></o:p></p><pre>-- <o:p></o:p></pre><pre>Doc / Dr TLUD / Prof. Paul S. Anderson, PhD <o:p></o:p></pre><pre>Email: <a href="mailto:psanders@ilstu.edu">psanders@ilstu.edu</a> <o:p></o:p></pre><pre>Skype: paultlud Phone: +1-309-452-7072<o:p></o:p></pre><pre>Website: <a href="http://www.drtlud.com">www.drtlud.com</a><o:p></o:p></pre></div></body></html>