Stovers,
I received a very well-stated question in a private message, and I am sending a public reply without the info of who asked the question.
Question: “In the Stovers mailing list I always read about ratio between primary air and secundary air (1:4). I never read about ratio between surface (diameter of holes x number of holes) of primary air and the size of cylinder of gaseification/combustion chamber, and, I suppose, also the size of chimney that can regulate the primary air flow. I thank you if you can give me this information.”
It is the ratio of the two amounts of air that enter that is important, not the size of the holes. The reasons is because different amounts of air will pass through a hole depending on the push, pull, and even the temperature of the air. Also, what is on the other side of the hole (such as a mass of fuel) will offer different resistance the to passage of the air.
The ratio can be calculated to for “perfect” combustion (stochiometric) . But perfect is not a natural condition, so some extra air (to have sufficient O2 available) is usually added. Also, conditions can change, such as even a change in the direction of the wind. Therefore, the RESULT is more important than the theoretically correct action.
Paul
Doc / Dr TLUD / Paul S. Anderson, PhD
Exec. Dir. of Juntos Energy Solutions NFP
Email: psanders@ilstu.edu<mailto:psanders@ilstu.edu> Skype: paultlud
Phone: Office: 309-452-7072 Mobile: 309-531-4434
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Cheers
Mario Santi (Grosseto , Italy)
cell phone (WhatsApp) 00393334409650