[Stoves] Magh Utham Woodgas Burner
Paul S. Anderson
psanders at ilstu.edu
Mon Jan 5 10:24:29 CST 2009
I also congratulate Sai Baskar for his innovative work. This is how we all
learn and progress.
My comments relate to what Crispin wrote:
Quoting Crispin Pemberton-Pigott <crispinpigott at gmail.com>:
> It is important to see that all the flames have reached the outer wall of
> the combustion chamber. This is not so good. The flame will chill against
> the outer shell and increase the CO level in that region.
I think I disagree. These are not regular flames of hot gases entering into a
mass of air. These are inverted flames of air entering into a mass of hot
gases (as Crispin correctly noted later in his message). As such, if the air
jet reaches the outside cylinder, it spreads out the air stream and does not
cool the gases against the cylinder. I am not advocating massive jets of air
to that wall, but experimentation is justified. Might have desirable results
such as keeping CO from sneaking up the side walls.
I totally agree with Crispin's next comments:
> In addition, there is still a triangular region between each of the flames
> through which it is possible to pass at least some smoke that remains
> So.I suggest that without changing anything else, increase the number of
> holes, completing a ring of holes in the same vertical position as the '8th
> hole', but recalculating the hole diameter to the total area remains the
I have not read that the hole diameters and associated secondary air
been rigorously calculated and/or emperically tested to get the proper amount
of secondary air. Yes for more holes, but experiment on how much air is
needed. Unfortunately, without CO emissions testing, it is a qualitative
"impression" of when the right amount of air is present, not a quantitative
> There will then be 14 flames radiating from the centre, giving what may be
> 100% coverage of the combustion chamber, but with the total area of the
> secondary air holes being equal to the present 8 holes. If there are any
> holes through to top plate (it appears there are) leave them closed.
Maybe. Better to just test to see if there is any impact of having
open or closed.
One other thing to test is the use of a "concentrator disk" or "lid" as
in Paal Wendelbo's Peko Pe TLUD and in my Champion TLUD (and in our current
joint efforts in India). The concept applies to bringing the flames/gases/air
together through a constriction to cause increased mixing and the avoid the
"wafflely" wavering nature of gentle flames. Because of the innovative entry
of the secondary air via the vertical central pipe, the "lid" might
have a 4 to
6 inch (10 or 15 cm) diameter hole in a lid that covers over a 7 or 8 inch
diameter fuel cylinder. This might eliminate the need for any hole in the
outside cylinder. Only experimentation will clarify this question.
Best wishes, and please keep us posted on your progress (including telling us
things that do not work.)
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