Thanks for the overwhelming comment; these are just observations made of how gas-emitting-hot and cooler wood behaves!
The gas-emitting hot wood is re-lightened in a snap, while cooler wood has to be re-heated before it can support a flame, when air is “offered”.
Taking intake manifold vacuum as a signal criterium, is a bit vague, as the gasifier already is under considerable vacuum succing through the 2 smaller-nozzle rows…
The positions of flaps are independent of vacuum developments, and can directly manouver microswithes.
The small-nozzle row near the main nozzles are there to guarantee fast reignitability after a longer idle.
They work like “pilot” flames.
The lower small-nozzle row has a “harder than normal” working condition; it has to handle the pyrolysis "cloud"
now streaming down from above boiling wood.
Let’s see what the idle air flow looks like, before “selling” or “auctioning” the flow areas for different nozzles!
Cold & Empty flows according to the
Royal Academy of Science in Stockholm
in the book Gengas
Enlargements as multiples of the Kelvin 273,15 deg. Celsius “segments”… starting from abs. 0 point.
“everyday” formula with main factors baked-in:
WOT: l X n X 3
expressing liters per second net gas at WOT
l = liter displacement
n = RPM : 1000
3 = baked-in constant factors
ex: 2500 RPM : 1000 = 2,5
(the 1000 is already baked-in into the constant factors)
1,6 X 3 X 3 = 14,4 l/s … l net gas/s at WOT
1,6 X 1 X 3 = 4,8 l/s … WOT X (1- 0,65 atm = 0,35) =
1,68 l/s net idle gas consumption.
The cool air needed for this production is: 60%
of the cool gas.
1,68 X 0,6 = 1,008 liter/s
So, the idle air flow is about 1 l/s
The full flow air is 14,4 X 60% = 8,64 l/s
The full flow has to include the idle air flow,
as the small nozzles are never closed!
Now, we have to “auction” 1 l/s air flow for both sets of idle nozzles together.
I propose 1/3 for the top set and 2/3 for he lower ones.
meaning 0,33 l/s for the top ones’
and 0,66 l/s for the lower ones’.
Actual nozzle flow areas and velocities…
I am taking a pause and listening to comments…
Are the 3 mm holes 35 or 45 ?
I find it difficult to apply the nozzle-switching system without “ripping up” a lot of the two surrounding cylinders around the hearth tube.
Eaven then, the sevicing of the switch-slide would be hard to perform. Perhaps in next build, where it is taken into account when planning.
If done now, the upper part of the air mantel has to be separated below the nozzles from the rest of the mantel, and then fed through an outside valve from the lower, separated part.
The hard part is still those 35 or 45 3 mm holes, which are “bleeding” in air, making any blasting pressures impossible to achieve for any small nozzles at idle!
Still, you need to put in heat insulation between the new silo and the heart mantle-part, otherwise the condensing will only be a dream…