Post by luddite on Mar 23, 2016 17:57:37 GMT -8
Hi everybody.
Peter, if you happen to pop around. I'm thinking or recycling this one into a heater
donkey32.proboards.com/thread/799/barbie-core-horiz
The firebox internal dimensions are 30cm wide 30cm high and 50cm deep. When a 18cm riser calls for 26 wide 39 high, and 52 deep.
I was wondering if it was Worth narrowing the firebox. Since it's ceilling is lower. CSA of the firebox is 900cm² while the 26x39 makes out for a 1014cm². Pretty close. Air speed in my firebox should be a smidge faster. But when burning fully, i have a bit more wood surface exposed. So more unburned gases.
I know that as a barbie core, exept when fully hot, it was smoking. But my riser is only in the 80cm range, while it needs to be about 130cm.
I can always make another firebox. But for the moment, i'd rather not.
What do you say? It would have door, P channel. I barrel on top. Followed by bells.
Thanks.
Max.
Hello all. I am also (like satamax) considering altering the shape of the peterburg batchbox so as to be a horizontal ten sided cylinder built with split firebrick ripped at 18 degree bevels resulting in an 11 inch interior diameter. I do know of the hard work Peter put into this design and also that I am foolish for deviating but this is an attempt to retrofit a 6" j-tube encased in an 14.5" id propane tank. The cross-sectional area of cylinder (an 11" circle) is 95 sq inches (same as traditional), length will be 17"-18" (same) so volume will be near the same but determined by size and angle of backwalls (not fun math at all). With respect for the fact that this build will unlikely ever be repeated (due to difficulty of construction) and as such may not serve the collective, I ask for advice.
Foremost concerns and considerations
1. Expansion of primary burn cylinder and how much space should I leave between outside of firebrick and the encasing steel tank? With what should fill that gap? Pearlite? Would the cardboard trick be enough? Is thin ceramic fiber necessary?
2. Port profile? Due to the widening and shortening (in height) of box should I also consider altering port profile to be shorter and wider?
3. Angeling of backwalls towards port. Just wondering how large a difference this has been observed to make and if it may be worth the effort to shape. I am planning to use pre-port secondary air device as designed by Mathew Walker as space is lacking for the p-channel option (else I'd do both and play). I can't help but wonder if shaping to look more like a venturi might be optimal.
4. How bad an idea is this? From 1 to 10
Of course I have no testing equipment but wish I could spend my days contributing to this awesome endeavor. I envy those who do.
Thanks
Ned