First, you wrote about
> makes for very low emission rates independent of fuel type and quality?
Very low emission rates are the result of very complete combustion,
meaning sufficient time, temperature and turbulence to get the
combustibles to be fully combusted. And those 3 T’s are better done
with air (O2) mixing with gases than with air swerling around pieces of
solid wood, coal, etc, that keep cooling the processes that are trying
to yield the gases. The creation of the gases at places at least
slightly separated from where the gases will be burned is the
distinctive mark of a GASIFIER. GasifiCATION occurs in all such fires,
but the SEPARATION is accomplished in a gasiFIER.
Second, you wrote:
> That a WBT can deliver “stove performance” independent of fuel quality
> is presumptively dubious.
Amen!!! That is why pellet-fuel (with uniform size and moisture
content) can have an easier time to be clean burning than do many other
biomass types. In recent years there have been allowances for the
stove maker to specify which fuel is to be used.
I remember back in 2004 to about 2010, the testing equipment being
established at and by Aprovecho had ONE “official fuel” so that the
results between stoves could be compared. Sawn kiln-dried Douglas Fir
wood from a woodworking factory was THE fuel, and was close to perfect
for Rocket stoves. That requirement gave me lots of problems with
tesing of the TLUDs.
On 7/27/2017 12:07 PM, Nikhil Desai wrote:
> Crispin, Paul:
> A dumb question: Is it the production of gases or the high
> temperatures — or some sequence thereof — which makes for very low
> emission rates independent of fuel type and quality? Or is it the
> relatively steady power requirements of a heating stove?
> It suddenly dawned on me – reading a children’s book – that the type
> of large heating stove used in Europe that also doubled for cooking
> was because of the type of cooking: grilling, roasting, soups and
> stews, but less of frying and spicing as in Asia.
> Or that the cuisine responded to the availability of energy delivery
> Bernard Lewis wrote a brilliant essay called “In the Finger Zone”,
> where he said (writing from memory), “The world can be divided in
> three areas by way of eating: fork zone, finger zone, chopstick zone.
> These areas are also roughly fresh cream zone, sour cream (or yoghurt)
> zone, and no cream zone.”
> Now I am thinking of world geographies and human cooking histories as
> “Cookstove zone, Heating and cooking stoves zone, and Combo stove zone.”
> I still hold that for cooking-only stoves with a rich enough menu,
> biomass of low energy density has different emission rates according
> to fuel quality (and operating practices, of course). That a WBT can
> deliver “stove performance” independent of fuel quality is
> presumptively dubious.