[Stoves] Secondary combustion technology in Sedore?

[AJH]

On Sun, 9 Mar 2008 12:30:23 -0500, Dick Gallien wrote:

>l. Understandably, most posts are about the lives and environment that are 
>being destroyed in third world countries, mainly because of poor cooking 
>stoves.

Yes this is the prime motivation for this list

>
>This URL is my wife's first attempt and the "old goat" tinkering with the 
>Sedore, is looking for suggestions on the ideal proportion of primary to 
>secondary air.

In the past I've tried to encourage posts regarding space heating for
the western nations away from the [stoves] and onto [bioconversion] or
[bioenergy] to maintain focus on this list, lack of interest has meant
[bioconversion] is no longer maintained.

>up the ash auger. I have a straight 19' stack, the 12' going through and 
>above the roof is Metalbestos.

my first observation is that some deposits in the flue are nearly
inevitable and more so at start up. So any condensate in the flue will
become tarry black and run down the flue. Your flue has been installed
upside down, the sockets should be below the male parts so that any
tars flow downwards and stay within the flue.


> The small amount of creosote started when 
>burning dry wood, before I experimented with green chips. I make one pass a 
>yr. through the stack on a large Quadrafire stove and get just a little 
>creosote. When the lid is left open, after filling, the roaring looks like a 
>white blueish blow torch, in the photo, with the ash door open .5". When the 
>lid is closed the roar stops immediately, as the down draft is cut off, 

This is effectively a primary air control, the primary air controls
the power.

>forcing the stack to pull from the four 3/4" pipes that enter 6" above the 
>base, across the 18" burn chamber, through the coals and under the caste 
>baffle, into the secondary burn chamber. I don't see any flame from the 3/8" 
>holes, every inch on the 3/4" secondary burn pipe I put in. Should I have 4 
>to 5 times more secondary air than primary?

I cannot picture this properly but you do need over 5 times as much
secondary air, the amount over the stoichiometric amount increases
with higher moisture content fuel, I often seen 10% oxygen in the flue
of small boilers burning wet fuel.
>

>
>Would appreciate any questions or suggestions on how to improve the sec. 
>combustion.

A small blower on the secondary air side ( as long as this doesn't
pressurise the device which would compromise primary air flow and
safety) and don't over run the device by using air inlets other than
the primary air device (i.e. leaving the top door or ash door open).

We may be experiencing problems with nomenclature here, if there is a
flame then there is secondary combustion, if there's smoke, soot or
condensate then the secondary combustion is poor, often because it is
quenched, the air supply is wrong or it hasn't the space to burn out.
These things all being interrelated and addressed by the three Ts.

AJH