[Stoves] Secondary air slots and deflectors

[Jock Gill]

Friends,

I get this flame pattern when I use a slot for secondary air with three deflectors just above the slot.  This tends to keep the flame in the combustion zone between the top of the fuel load and the bottom of the deflectors.  The total area of the three deflectors should be around 50% of the surface area of the fuel.  I find this gives very clean combustion as long as I use the least amount of primary air required to sustain pyrolysis.  As the primary air increases, the gap must increase.  The more primary air the more rapid the pyrolysis and the hotter the stack gas. But it is very hard to obtain a really clean burn if the pyrolysis is really fast. Or so I find.

Test set up looks like this:

-------------- next part --------------
A non-text attachment was scrubbed...
Name: image.jpeg
Type: image/jpeg
Size: 20480 bytes
Desc: not available
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20130225/b41baa38/attachment.jpeg>
-------------- next part --------------




-------------- next part --------------
A non-text attachment was scrubbed...
Name: image.jpeg
Type: image/jpeg
Size: 20480 bytes
Desc: not available
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20130225/b41baa38/attachment-0001.jpeg>
-------------- next part --------------



Slot for secondary air w/ three deflectors.


-------------- next part --------------
A non-text attachment was scrubbed...
Name: image.jpeg
Type: image/jpeg
Size: 156795 bytes
Desc: not available
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20130225/b41baa38/attachment-0002.jpeg>
-------------- next part --------------




-------------- next part --------------
A non-text attachment was scrubbed...
Name: image.jpeg
Type: image/jpeg
Size: 137989 bytes
Desc: not available
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20130225/b41baa38/attachment-0003.jpeg>
-------------- next part --------------



-------------- next part --------------
A non-text attachment was scrubbed...
Name: image.jpeg
Type: image/jpeg
Size: 171508 bytes
Desc: not available
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20130225/b41baa38/attachment-0004.jpeg>
-------------- next part --------------



The flames is pretty well contained in the combustion zone between the top of the biomass and the bottom of the deflectors.  The combined area of the three deflectors is about 50% of the surface area of the biomass fuel - more or less.  

Biochar yield will be about 20% of the weight of the fuel load.

This concept scales very well to fuel cylinders with diameters of 6 inches (15+ cm).

I have several short videos of the combustion action in this setup.  Just drop me a note and I will send them.


Regards,

Jock

Extract CO2 from the atmosphere!