[Stoves] Use of the Swosthee Stove

[AJH]

On Fri, 4 Aug 2006 19:36:18 -0700, Tom Miles wrote:

>One real advantage of the Swothsee is probably the continuous fuel feed that
>we don't see in the batch fed metal stoves using the vortex. 

Yes and the fact it will accept long sticks like the rocket.
>
>The Swothsee would seem to be a natural for FAN experiments in the upcoming
>Stoves Camp. I would put a variable speed fan on it and try it with natural
>draft and various fan levels. 

The trouble I see with this configuration is being able to pressurise
the air supply whilst maintaining the fuel feed. The air pressure
tending to vent via the fuel feed rather than the top. Now with a
heating stove you may get away with an induced draught fan, if it will
stand the heat. The Dasifier gets around this problem by using a
compressed air ejector between the primary and secondary combustion
but litre for litre of air moved compressed air is both costly and the
ejector relatively inefficient. It was for exactly this purpose I was
looking at steam powered eductors until a TEG powered fan started
looking better.

Either way if the stove is working in a conventional updraught mode
then we know that primary air is about 1/5 of the secondary air and we
only need a depression in the primary part. If I interpret the Swothee
drawing correctly then the air is initially separated from the
combustion chamber by a spiral like box, it is unclear how the
inverted open bottomed cone at the outlet to the combustion area
functions. If the main vortex could be configured to supply secondary
air via a eductor, possibly using a simple fluidic lip, on the Coanda
principle, then a slight depression below this would supply primary
air to be sucked in by the fuel.

>High heat flux in the vortex should make it a
>good candidate for a TEG powered fan.

Yes I think the cyclonic type burners make good candidates for a TEG.
In this instance if the TEG is incorporated into the inner wall of the
air supply then the hot side would be supplied with heat from the
combustion chamber and the cool side would take heat out via the
incoming combustion air, as Crispin has pointed out all waste heat is
then re circulated to the cooker.

How about this for a starter project Steve? Are the drawings on the
site Tom cited good enough to work from?

AJH