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Dear Julien</div>
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I have not seen any forced draft stoves from Nurhuda. Are you sure it has a fan? He has specialised in ND so far. All stoves submitted to the CSI project, anyway. </div>
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BBM 'Crispin'</div>
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<div><b>From: </b>Julien Winter</div>
<div><b>Sent: </b>Sunday, March 6, 2016 03:44</div>
<div><b>To: </b>Discussion of biomass cooking stoves</div>
<div><b>Reply To: </b>Discussion of biomass cooking stoves</div>
<div><b>Subject: </b>[Stoves] Flame center go down into the combustion chamber</div>
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<div dir="ltr">Dear Roberto et al.;<br>
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<div>There are a couple of reasons why you may get secondary air settling down the middle of the burner.<br>
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<div>1) When there is not enough syngas to create a gas flame across the entire cross section of the burner, then flame and buoyancy will localize the updraft. If the flame originates at the orifices of secondary air, but can't extend to the center of the
burner, then there gases in the middle fo the burner may settle.<br>
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<div>2) If syngas is entrained into jets of secondary air, then it will be pulled towards the origins of the secondary air jets. I saw this happen in on of my early burners. There was a torodial ring of 'smoke' under the secondary air jets.
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<div>The radial movement of syngas let me to experiment with burner diameters and find that a burner that was 1.2 x greater in diameter than the TLUD reactor worked better than when the diameters were the same. The wider burner gave slightly more horizontal
space for flame expansion. The result was a faster gasification rate (which I presumed, to be because I had a hotter, more efficient flame).<br>
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<div>One final note. Roberto's burner is natural draft. Muhammad's burner is forced draft. We must be careful using observations from forced draft burners to explain natural draft burners, because they are completely different animals. To get the same pressure
in a forced draft burning using natural draft, we would need a riser several meters tall.<br>
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<div>Cheers,<br>
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<div>Julien.<br>
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<div dir="ltr">Julien Winter<br>
Cobourg, ON, CANADA<br>
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