[Stoves] Cyclonic sorting/cooling

[AJH]

On Wed, 02 Aug 2006 12:06:35 -0700, drew wrote:

>Interestingly the cyclonic effect could be adding to the efficency of 
>the device, not by mixing but by sorting,  the centripidal force 
>throwing heavier/cooler gasses to the outside, while the hot light 
>gasses move inward.   

This is what happens and a turbulent shear layer exists at the meeting
point. A drawback of this is that dilution air exits without entering
the combustion, so it is inherently a high excess air device.

Of course the burners I have built using this principle have all been
fan powered top lit devices. Their advantage is that power control is
all managed by controlling one air flow, the feedback to the fuel
being relatively low that thermal runaway doesn't occur with moderate
moisture content fuels and as Crispin has said the technique allows
the incoming air to cool *both* sides of the combustion chamber steel
with no special need for protection yet outlet temperatures of 1000C
are attainable.

Given vortex pocket ash collectors and a thermo electric generator for
the fan power and this may work well as an institutional stove burning
a fine high ash fuel, like rice hulls.

AJH