[Stoves] Re Alexis Belonio article

[Crispin Pemberton-Pigott]

Dear Andrew

Would you be willing to bet 5 pence that the heat in the steam (heat to boil 
and latent heat of vaporisation) is sufficient to tip the scale the other 
way?

>...it more likely the endothermy of the vapourisation
>of this small amount of moisture in the primary
>combustion zone was just enough to reduce
>temperatures in this zone to below the temperature that pyrolysis
>offgas products may crack...

Perhaps this is still small potatoes compared with the gain provided by the 
extra draft and the better mixing.

In the video the flame sounds like a paraffin pressure stove, and for the 
same reason I feel: small shock waves from the flame passing through 
episodes of air-fuel and air as they mix in free space.  The main beneficial 
effect is to shorten the flame which immediately increases the temperature. 
Now that he has a really good flame, Alexis has a materials problem...

Alexis, can you measure the temperature of the steam coming out of the jet? 
That heat together with the preheat of the air drawn through the burning bed 
might turn out to be significant.

Thanks
Crispin