Aof manifold outside of evap

[das fisch]

Looking at the most cost effective way to add aof to my homemade 2x5 evaporator, and was thinking of the following.
Would it be possible to make up a aof manifold out of copper pipe, mount it on the outside of the evaporator, then drill thru the exterior steel, arch blanket and thru bricks and inset 1/4" copper "nozzles"? This way the copper would be protected from the heat and I might be able to reap the benefits of more air into the firebox.
I already have a 2" stainless tube with holes drilled which provides auf.
Any thoughts would be greatly Appreciated

[jmayerl]

If this is your only option then use black pipe. It's much cheaper, holds up to heat and can be welded

[maple flats]

Great plan if you use the black pipe. In-fact it is an option stated in the publication I got my original data from. Be sure to aim the nozzles down at the correct angle for best results. I wouldn't use copper because it will have issues as it is in contact with refractory cement, fire brick and the heat in the firebox. Besides, jmayerl is right on the price too. Just follow the directions in the Proctor research paper. link:
http://www.uvm.edu/~pmrc/Combustion.pdf

[das fisch]

Flats, that is a great write up. Thank you very much

[RyanB]

last year I added AOF to my small 2x4. What I did was use 2x4" steel C-chanel and I welded a horizonal piece to either side of the arch just below the top surface where the pan meets the arch. Before I did this I drilled aproximatly 24- 1/4" holes on either side of the arch aprox 2" down from the top and spaced every 2" apart. They go right from the front of the arch right to the back of the pan. I then welded the channel to the side of the arch and connected the two "now manifolds" together by bringing a short section of channel down on either side to the bottom of the ramp and then 1 other piece under the ramp. I then cut a 2" hole and welded a section of black pipe to lower piece of channel. I attached a PVC 2" Valve to the pipe and then attached a 2" pipe T to the bottom side of the valve. I then cut a 2" hole thru the back of the fire box and welded another 2" piece of black pipe to it and installed another valve. Sounds confusing but I will try to find a picture and attach to this post! What I was able to do was run AOF and AUF and fully regulate the air volume going to each section. It worked amaxing and because the 1/4" air holes were going thru 2" of fire brick there was no issues with nozzles melting or anything like that and none of them became plugged or anything also. For a blower I used a 2HP 1800 cfm dust collector out of my shop that I jimmy rigged up....it was deffinatly over kill but worked amazing and my wood consumtion was next to nothing and re-fueling was about every 40 minutes or so.

Here is a picture I was able to find. All in all it took me about 4 hours work to retro fit it to the arch and sure am glad I did!
http://i52.photobucket.com/albums/g30/RyanBambach/46580_10151588586870833_1315155410_n_zpsfcd6a6be.j pg
http://i52.photobucket.com/albums/g30/RyanBambach/483518_10151588582350833_1565352602_n_zps322e066a. jpg

[maple flats]

It's great that showed an improvement, but I believe you could have gained more. The air in should enter 6" below the pans. While you are burning hotter, you are likely losing some of the efficiency gain potential because you blow the air in too high and end up cooling the pan some. You could have gained even more IMHO.

[CharlieVT]

Looking at the most cost effective way to add aof to my homemade 2x5 evaporator.....Would it be possible .....mount it on the outside of the evaporator, then drill thru the exterior steel, arch blanket and thru bricks and inset 1/4" copper "nozzles"? .

My previous post regarding AOF manifold mounted outside the evaporator may give you some ideas (post #6 in this thread):
http://mapletrader.com/community/showthread.php?21545-Request-for-Air-Over-Fire-Pictures&p=233064#post233064

I wouldn't use copper tubing for nozzles. I used carbon steel tubing with nozzle tips flush with the face of the firebrick and refractory cement. Stainless would have been better, but I think that the carbon steel nozzles will be protected by the brick and mortar.

My theory is that it doesn't matter how you get the air into the firebox, as long as you follow the principles for air distribution inside the firebox outlined in the UVM pdf document:
http://www.uvm.edu/~pmrc/Combustion.pdf