[Stoves] Torrified Pellets

[Crispin Pemberton-Pigott]

Dear Dean

 

I can't see why you would try to attribute to a fuel, the ability of a stove
to burn it. Changing the fuel enough until it matches some stove's capacity
to burn it is not telling us anything except about that particular
combination. When we include the burn cycle and the container that seals the
top of the stove, all 4 contributing variables are present.

 

It does not surprise me in the least that the interns could not find a
statistically significant relationship between the performance of a system
with 4 input variables and only one of the inputs.  Changing a fuel until it
performs well in one stove, and then putting that 'cleaner' fuel into a
different stove will give a different emissions level because it is now a
different set of contributing factors. 

 

The conceptual error is to attribute to a fuel the performance of a stove
burning it. Keeping the question simple: when you have a clean-burning
stove+fuel combination, what is it that is clean, the stove or the fuel? The
stove developer claims he has a 'clean stove'. The fuel developer says he
has a 'clean fuel'.

 

The obvious answer is that only the combination can be evaluated.

 

Burning torrefied pellets in some crappy stoves that can't burn wood tells
us nothing about the fuel combustion potential of wood or torrefied pellets.

 

Regards

Crispin

++++++

 

Dear Dean, 

Here you say that the ladies observed no statistically relevant results (in
spite of trying, which seems to me a contradiction of scientific method: you
try hard only to observe parametric, repeatable data and report how it
either confirms or contradicts predicted results, not strive for results
themselves. A designer who has an objective for a stove is hoping that a
feature included in the design will achieve a controlled effect that will
tweak some parameter of performance, but testing is just trying to report.)
But then further down you repeatedly state that fuel preparation is so
important: "With biomass the preparation including recipe, drying, pellet
size, etc. makes a big difference in emissions when trying to get down to
the very low levels needed to protect health." This is much too simple.
A stove will have design features that determine whether, with a particular
fuel (with variables: contained moisture, contained minerals, contained
biological composition, granularity, etc.) all of that evil smoke can be
combusted or not -- once the primary air is done doing two things: providing
it with O2 and moving by it and thereby cooling the fuel and the resultant
smoke to a degree. It's very important to understand that enough _excess_
primary air will cool both the fuel and the smoke which migrates with it
further through the stove to such a lower temperature, that the introduction
of secondary air will no longer sustain complete combustion. When there is
no complete combustion everything left over is bad one way or another, but
naturally there are degrees of incomplete combustion.

I see that you have responded to Alex on a question of his while I was
writing this, but I'll try to maintain thread coherency by asking a
follow-up question there.
regards,
Ron






On 25.05.2015 16:49, Dean Still wrote:

Dear Frank, 

 

They tried but the results did not achieve statistical significance.

 

Best,

 

Dean

 

On Sun, May 24, 2015 at 2:58 PM, Frank Shields <franke at cruzio.com
<mailto:franke at cruzio.com> > wrote:

Dear Dean, 

 

 

Did the three women interns doing the study of types of fuels and their
corresponding combustion qualities come up with a final report? or planning
to do so?

 

I would be very interested in seeing this if it becomes available. I think
this very important information as a precursor to developing a series of
tests designed to determine if a fuel is suitable for a specific stove or
predicting problems when using. All needed for BOX 1 of the six box system. 

 

Thanks

 

Frank

 

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