Super-hot changes secondary burn - anyone else notice this?

[precaud]

On every EPA stove I've ever owned, once the secondary air pieces (whether manifold or tubes) get to a certain temperature toward the end of a fire (super hot!), it seems the air coming out no longer has visible "streams" and that flames are actually repelled as they lick near it. Combustion is still happening, but the mixing is no longer visible. I wonder, what's going on that makes this happen?

 

[berlin]

lack of enough volitiles, stochiometric ratio fuel/air is too lean near the burn tubes during the end of the burn cycle.

 

[precaud]

What you're describing is at the very end of the flame. I'm talking about earlier than that, when there is still plenty of flames (hence volitiles). It's almost as if there's a 'layering of air' that occurs that keeps the flame from touching a super-heated surface.

 

[berlin]

post a picture

 

[Corey]

I have seen what you describe.

I suspect that when the heat gets that high, the volatiles are brunt as they come off the wood and like berlin says, the extra air pouring out of the burn tubes maxes the mix too lean to burn.

Corey

 

[precaud]

Could be. I also see some stringey threads of unburned something floating around at the same time.