Primary/secondary air ratio

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Wade

Member
Sep 23, 2008
51
Manitoba
Is there a ratio of primary and secondary air that works well for gasifiers? Is the location of the primary important (high- low)? Would you just put large pipes in both and adjust the intakes for the sweet spot?
 
Wade said:
Is there a ratio of primary and secondary air that works well for gasifiers? Is the location of the primary important (high- low)? Would you just put large pipes in both and adjust the intakes for the sweet spot?

Are you building your own? The 'large pipes' bit has me wondering.

The trend seems to be to introduce primary air closer to the bottom, though my EKO introduces it at the top. Secondary air is typically introdcued through several small inlets in the nozzle throat.

I really don't know the ideal ratio. It probably has a lot to do with the geometry and flow patterns in your primary chamber - a more complete primary burn would need less secondary air.

I believe that the ideal air/fuel ratio is about 1.6 times stoichiometric. If I remember right (I don't have my spreadsheets with me) that works out to about 1 cfm of air for every 3000 BTU/hr.
 
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