What is the optimal air flow rate in fluid bed roasters?

[J.Jirehs Roaster]

Any other ideas?

Sorry... could not resist   

[Warrior372]

Any cheaper ideas   ?

[John F]

In my imagination version the roast chamber would have been almost directly on the heater. Maybe a small spacer if the heat is too intense right at the exit.

If you tried that would it loft any amount of beans, even 1/2#?


 

[Warrior372]

No. I tried that. The problem with the propane tube is there is really only airflow right at the end of the tube itself, and it is very minimal. The actual flames from the propane tube almost go to the end of the tube when it is on high, so you just charr the beans to bits in seconds. I tried with the chamber directly on the tube, 1' above it and 2' above it. No dice, just charred beans. The air from the propane tube alone might have moved 1/6 of a pound.

[John F]

Do they make in-line fans rated for 500 degree heat?

A booster fan on the hot side would work wouldn't it?

[Warrior372]

Like a duct booster fan? The highest I saw any rated to were 210F. They were around $300 and only blew at about 200CFM. I have that monster of a blower blower now, I think it is rated at 1050CFM and that is at 8". I just need a way to heat all of that air now. I am thinking a high pressure cast iron propane ring burner might work. You can attach an adjustable psi adapter to make them crank out about 160-180,000btu, and they only cost about $12. I think I could find a way to mount it just above the blower outlet inside the duct tubing. I am just worried about the burner not having a pilot when I would be pushing large amount of propane though it.

Any idea on how to hook up something like an electronic axial coil heating element? I could mount one of those right at the output on the blower and it would make it into a huge blow dryer!