AOF arch build help

[tom jr.]

guy's, I am in the middle of building an aof gassification arch and have a few questions. first it is a 3x12 so currently the plans for firebox(inside) is 32'' tall (grates to pans) 30'' wide(bricked) and 48'' deep. my question is 48'' deep enough? I herd 2/3 the length of the arch for good gassification but thats
8' deep on a 3x12.

[Indiana-Jones]

Tom is a gassification arch different than a regular wood burner with AOF?

[Flat Lander Sugaring]

http://s40.photobucket.com/albums/e2...0Arch%20Build/

you need 1200 deg temps at front of arch for gasification to work properly. yes I have close to 2/3 but I know a force5 fire box is also close o 2/3 of arch.
check out my pics my AOF tube is 3"x6" so make sure you dont chew up your fire box width like I did.

[Waynehere]

I read that the 2/3rds is more for the direct radiation from the firebox then the thought of just using the flames to lick the sides of your sap pan to make her boil hard. I knocked mine back so the direct line of sight from the firebox should heat the pan better, hopefully.... I only have a 2x6, but dropped my bottom in the firebox to try and gain more area there. I added AOF as well. Can't wait to run a test boil soon. Although it won't be a gasifacation arch, I hope to make it way more effecient then it was.

Good luck....

[nymapleguy607]

Having a firebox 2/3rds the length of the arch I believe is to allow for good mixing of the air and smoke as well as give enough space for the amount of air being forced in. Tom, in your case with a 3x12 I would go with a 6' firebox, you still need to be able to fill the firebox and push the coals back. You should benefit by having a longer arch because it give you alot more time to absorb heat before it goes up the stack.

[tom jr.]

good stuff guys, keep it coming! i think i am going to go 6' with the box as ny suggested. the basic design is a 802maple arch like tukermtn built with air in front and back no ramp in the back as i have a raised flue pan. i did break down and buy the forced draft grates though waynehere what size raidial blower is that u have?
I was thinking about a dayton 7d749 8 15/16'' blower from grainger for mine

[nymapleguy607]

Tom, I think I would go with the next size up blower. I have the 8-15/16ths size blower on my 2x6, you can always limit the blower opening to cut down on cfm's, you can't get more out.

[tom jr.]

ny, your right on the blower think i will go to the 10 9/16'' for the cfms should be able to do the auf with it also. what do you guys use for nozzles? ss pipe or a heavy wall steel pipe and what is a good size? still thinking on the depth of the firebox maybe 5' deep and changing to a slight ramp maybe 10-12''down from the bottom of the flue pan till it hits the bottom of the pan 36'' from the back. then i can still have a good size wall for the back of the firebox for brick and a couple rows of air nozzles, what do you guys think? flat lander, i see what you mean with the tube mine is 2''x4''I.D thinking maybe thats to small now

[Flat Lander Sugaring]

ny, your right on the blower think i will go to the 10 9/16'' for the cfms should be able to do the auf with it also. what do you guys use for nozzles? ss pipe or a heavy wall steel pipe and what is a good size? still thinking on the depth of the firebox maybe 5' deep and changing to a slight ramp maybe 10-12''down from the bottom of the flue pan till it hits the bottom of the pan 36'' from the back. then i can still have a good size wall for the back of the firebox for brick and a couple rows of air nozzles, what do you guys think? flat lander, i see what you mean with the tube mine is 2''x4''I.D thinking maybe thats to small now

jerry gave me size of AOF tube, I just asked to far into build right now to fix my problem.
so nymapleguy607 whats the product number on your high pressure blower for your 2 x 6
ok gotta go and order my SS ro vessels bfore they are all gone

[nymapleguy607]

jerry gave me size of AOF tube, I just asked to far into build right now to fix my problem.
so nymapleguy607 whats the product number on your high pressure blower for your 2 x 6
ok gotta go and order my SS ro vessels bfore they are all gone

The blower is a dayton 2c820, Its big enough I feed the AOF, and AUF with it. I used 1/2" tubing for my air nozzles I believe there are 13 across the back and then about 20 in the front between the door and the door frame. I need to try and post some pictures, I just hooked up the blower last night and was trying out the dampers and air distribution. If you want heavier nozzle material you can also use 3/8 threaded pipe nipples, Then you could drill and tap your air manifolds so replacing the nozzles would be a snap.