Blower

[Danielb]

The wife bought a bouncy castle for our daughters birthday party. Now i am wondering what i could use the blower for with my new arch i am building.
I have a new CDL 2x6 pan set with raised flue and 2x2 syrup pan.
Screenshot_20201018-210258_Chrome.jpgScreenshot_20201018-210245_Chrome.jpg

Would this be able to push enough air for AOF, or just AUF?
I am really hoping to incorporate AOF on my new arch i will be building.

Any thoughts are welcome. I am beginning to think it wont have the ability to build the pressure needed for AOF, but am hopeful

[maple flats]

Most likely both, I use one for both. To do that pipe the air into a Y fitting then have a valve in each leg. From the blower to the valves use a good size pipe, I used 4" PVC with any ells the long sweep style. I found mine works best with the AUF valve open maybe 25-30% and the AOF valve open about 75-80%. Yes they don't need to equal 100%. While my blower is not a bounce house blower it is the same paddle design. For my AUF the pipe enters the back of the firebox on the floor. it is a 4" heavy galv pipe, likely 18 or 16 ga. In that I have 3 rows of holes, 1 top center and one each facing the outer part of the grates. Those holes are about every 2.5-3" apart and end 6-8" from the front of the grates. My AOF follows the recommendations for nozzle spacing but I used what I had for tubing to make the manifolds. The tubing is 2x2x1/8 square. it works very well, but the instructions I used called for a 3" diameter for my 3x8 arch. At any rate, the fire is intense but maybe could be even better if I'd used 3" tubing. My nozzles are 1/4" black pipe every 6", face down towards the opposite side just above a grate at the sidewall. The nozzles are about 5-6" below the pan and go all around the firebox except where the fill doors are.

[buckeye gold]

It will work. I'd suggest adding a variable speed switch in your sugar shack. You can adjust it and turn it off at will. I have this one and it works great:

https://www.amazon.com/VIVOSUN-Varia...s%2C665&sr=8-3

[RileySugarbush]

The effectiveness of AOF relies partially on the high velocity of the jets of air. I recommend no throttling or slowing of the blower upstream to make sure full pressure is at the inlet of the nozzles. That pressure difference is what determines the jet velocity, and that velocity is what mixes the air with the unburned hydrocarbons. Throttling will reduce it.

I determined over air volume by selection of the nozzle number and diameter, and apply full pressure. My Koala bounce house blower provides about 8 inches h2o pressure and with big pipes to the nozzles it is full pressure all the way, resulting in 80mph jets. I bleed off some up stream and through a blast gate for adjustable under fire air. And I use a quick opening flap door on the blower box to shut off air for firing.

Many other ways will work, this is just my solution.

[Danielb]

Thanks for the replies. Dave, I was planning pretty much the same as your design for my AOF.
I will hopefully start building over christmas, but will see what ends up happening.
Also, i know that with nstural draft, i would be fine with an 8" stack, but with the forced air, would i be best to size up to a 10" stack?

[maple flats]

Danielb, by the way, when my high pressure blower was first used (by me, it came out of a factory that went out of business and was likely over 100 yrs old) I shut the blower off to add fuel. Then one time my teen age grandson forgot to shut it off and I noticed that no smoke nor sparks came out so from then on we no longer shut the blower off when fueling. On mine, I lay up the fire and light it using a propane weed burner torch (500,000 btu) with the valve open at about half way. I first aim the flame over the wood to initiate the draft for maybe 2-3 seconds, then I aim the flame at the bottom of the laid up firelay (each layer is 90 degrees to the layer below). I do that for about 2-4 minutes, until the fire is fully lit I close the doors and then turn the blower on. I am usually at full boil (1" deep in the front pan, and about 1/2" over the flues in my raised flue back pan) in about 8-10 minutes in the front pan. The back pan likely takes about double that. My blower never gets shut off until about 99+% of all coals have burned out when shutting down.
On my valves regulating the % of air flow to AOF vs AUF, I haven't changed the setting since my initial adjustments to determine what worked best. That was back in 2008 or 09 I believe, if my old memory is correct.
I didn't find a need for a larger or taller stack when I added the high pressure air. The air is high pressure not high volume, there should be no need for the bigger stack.

[jrgagne99]

I also have variable speed control on my blower. I put a brick in front to block off half the intake opening. :-)

[Danielb]

Thanks for the info. Dave, you are a real wealth of knowledge.

[vtbackyardmaple]

Any chance of a picture of this setup? I want to make one.