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

[garybt3]

Oh hell!
How can I make it any bigger???

[Tex]

Thank you! Some of us are getting up there in years and large type is easier to read.

[garybt3]

There, now that size looks about right...

If you want the larger schematic, just PM me with your email address and I'll send it out.

[Warrior372]

John,

I found the CFM rating for a torpedo forced air propane heater with 40,000 BTU, it has a 1/32 HP motor to push the air. This one is a Master BLP42 it's CFM rating is 175. Their 55,000 BTU version is rated at 275 CFM and has a 1/20 HP motor. Based on what the Sonofresco rep said the 1 pounder uses 100 CFM and the 2 pounder uses 'slightly more'. I think you are spot on with the 50,000 BTU unit you posted from Lowes! It should be able to do 2 pounds or slightly more in a similar fluid bed fashion. They have adjustable heat control knobs on the side like grill too, so as long as you had a digital thermostat at the top of the roasting chamber you should be set.

I think I might try this out, especially because if it doesn't work Lowe's will let you return it. Good call!

Anyone have any ideas on tubing?

-Mike

[John F]

I think I might try this out, especially because if it doesn't work Lowe's will let you return it. Good call!

You gotta follow up if you do....with pics.

[Warrior372]

Oh. . . I will. Would a torpedo heater work if you stood it straight up? Obviously suspending it somehow so air could still flow through the bottom end.

-Mike

[Warrior372]

I went out and purchased most of what I think I will need for this project yesterday. I would like to Update the stats on the 30,000 to 50,000 BTU Torpedo Blower from Lowe's. After checking out the stats in the instruction manual, it actually rings in at 300 CFM for airflow. . . it throws a lot of air around! Which means larger roasting batch to me . I did a quick check with my digital cooking thermometer to test air temp when the blower is on high. . . . it exceeded the thermometer's 500 degree F limit in about 30 seconds. So, we know the heat is there, we know the air flow is there, it will just be a matter of how controllable it is when everything is hooked up. I guess worse case scenario is I have to install a damper, that is if it blows at to high of a temp even on low.

Any ideas on where to get a glass cylinder for a roasting chamber? I was thinking maybe a glass candle hurricane. . . Any other ideas?

Thanks,
Mike

[John F]

My idea was not to go with glass but to get a chimney instead.

One of those charcoal starter chimney deals...

[Warrior372]

Hmm. . . the charcoal starters? What you put the charcoal in to get it really hot before putting it in the grill? I looked at those and they have holes in the side to allow airflow into the chamber. If that is not what you are referring to please elaborate.

The temperature I registered on low was 390 degrees fahrenheit!

Cheers,
Mike

[garybt3]

Mike,
you are definitely on to something here...

I think you might want to mock it up in all steel stovepipe, try out different diameters.

Maybe try using a steel mesh diamond grate screen that is thick enough, yet sized appropriately so that you don't have too many smaller diameter beans falling through it.

Cut and tack weld the screen for the bottom, and add on a handle, like a giant sized coffee mug. For the top do the same, making a hinged lid, like a giant beer stein, only it's a screen door 

I'd steer away from a glass chamber, for the time being.

I  :wav: your efforts!

[JoshInCA]

Any ideas on where to get a glass cylinder for a roasting chamber?

Would Pyrex tubing be a possible option for the ready-for-prime-time version? I haven't worked with it myself -- it was just what came to mind.

[MMW]

Any ideas on where to get a glass cylinder for a roasting chamber?

Would Pyrex tubing be a possible option for the ready-for-prime-time version? I haven't worked with it myself -- it was just what came to mind.

Yikes!

I think I'd order a new chamber from Sono and mash something up...

[Warrior372]

I was searching for an 8" to 10" tall by 6" to 8" diameter Pyrex tube last night on the net, and nothing came up. It is all very small in diameter. I think that would be the best bet though, if the proper size can be found, because it is tempered. In the meantime, I got a glass vase and a glass cutter . . . could be interesting. I am going to put stove grade mesh on the bottom, securing it with an air duct clamp. I am going to try to find a small hinge at the hardware store to make a hinged mesh top for the tube glass roasting chamber.

The stovepipe is a great / easy idea, but I really want to see the beans blowing around . Sonofresco chamber is also a great idea, but I am willing to bet they want quite a bit of money for that bad boy. The vase, glass cutter, clamps, and mesh rang it right around $25. Now it might not work, but being creative is half of the fun!

I am torn between studying for a Physiology test I have on Monday and making this roaster!

Cheers,
Mike

[peter]

I'm thinking about a candle chimney...  whether or not you'll find one w/ a 6" diameter is another thing.  I have a few 4", and maybe a 5", so you may be able to find one.

[Warrior372]

I found a 5" as well. I am tapering the Torpedo from 8" to 6", I put an 8" level walled guard around the 6" taper, and put mesh in it. It will allow me to roast in anything up to 6" in diameter. I am moving pretty fast on it, and might have it done sometime tomorrow. I think it is going to work surprisingly well!

I am about to go cut the 6" diameter vase down so that it is 8" tall. Wish me luck. . . .

Cheers,
Michael