[Stoves] Lots of smoke after a few minutes of clean burning

[Mangolazi]

Hi Andrew, 

The smoke wasn't bluish, it was white-gray. The flame didn't go out but it barely peeked out from the chimney. I didn't try lighting the smoke, maybe I should try it the next time. 

I'm trying to understand how the flame and smoke can change so quickly, even though the twigs used were roughly uniform in size and moisture. I get a clean burn about 3 minutes after ignition, a roaring flame at 5 minutes, then smoke starts appearing at 7 minutes. Don't laugh, I timed it :)

Does a smoky burn ever resolve itself given time? I always quench it at 10 minutes because I can't stand the ridiculous amount of smoke coming from the can. 

On May 8, 2016 4:18:31 PM GMT+08:00, ajheggie at gmail.com wrote:
>[Default] On Sat, 7 May 2016 20:04:21 -0400,Julien Winter
><winter.julien at gmail.com> wrote:
>
>>Dear Mango;
>>
>>One cause of a clean burn, followed by smoke, is if the flaming
>pyrolysis
>>reaches the grate before it has passed through all the fuel.  When
>this
>>happens, you end up with a bottom-lit updraft gasifier, with a
>charcoal
>>fire at the bottom.  The syngas exiting the fuel bed is rich in tars,
>>relatively low in reactive H2 and CO, so is very hard to ignite, even
>with
>>a pilot flame.
>
>
>Julien I have found when this happens the smoke has a bluish tinge and
>as you say becomes almost impossible to re light. This is presumably
>because the  pyrolysis offgas has become diluted by the combustion
>products of water and CO2.
>
>If the smoke given of is white with a yellow tinge  it can be a simple
>flameout because the flame holding has been lost. I used to see this
>when I had too long a flame. 
>
>However Mango describes the flame that gradually diminishes before it
>is lost.
>
>So what colour is the smoke Mango?
>
>Andrew
>
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