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snwcmpr
08/18/2019 4:31 AM
Awesome I sent an email to AllenB and JackH The email to JackH failed. I had screenshots of my settings.

allenb
08/18/2019 3:37 AM
Jack and I are enlisting help from our PHP site admin to try and solve as soon as possible. Thanks for letting us know.

snwcmpr
08/18/2019 2:53 AM
I got another PM last night......... No email notice.

snwcmpr
08/17/2019 7:36 AM
Email address correct. I constantly check junk folder. I turned off, then on, the setting to receive notice.

JackH
08/17/2019 7:10 AM
Also check that there are no spam filters set for email.

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Critique my roaster design?
ranfea
Hi all, my goal is to construct a fluid bed roaster capable of roasting a half-pound of coffee per go.

For the motor, I'm looking at this electric leaf blower, and for the heating element, I'm looking to dissect this heat gun.

https://www.amazon.com/gp/product/B0030BG1CC/ref=crt_ewc_img_dp_2?ie=UTF8&psc=1&smid=ATVPDKIKX0DER

https://www.amazon.com/gp/product/B00EU2T8GG/ref=ox_sc_sfl_title_4?ie=UTF8&psc=1&smid=ATVPDKIKX0DER

I'll use a pyrex baking tube, and a cocktail shaker to cap it off at the base. And then some machining magic to couple it to the mounting pipe.

Does it seem like this will get hot enough to roast a 1/2 pound?

I'm trying to upgrade from my current popper setup which can roast a max of 60 grams at a time (and that's with me constantly agitating with a shish kabob stick).

Edit: One possible improvement could be increasing the wattage of the heater to 2000W. Does anyone have a recommendation for a really cheap blower (or just the element itself)?

If I reclaim the air from the exhaust back into the pump, would this allow a 1500W heater to work?
ranfea attached the following image:
deleteme.png
 
renatoa
Not a critique, but a personal wondering... why nobody approach usage of flat heaters, as you can found in the popcorn base ?
You can obtain this way a more compact format, something close to Nesco machine, instead the columnar appearance we see for most fluid bed machines.
 
ranfea
renatoa wrote:

Not a critique, but a personal wondering... why nobody approach usage of flat heaters, as you can found in the popcorn base ?
You can obtain this way a more compact format, something close to Nesco machine, instead the columnar appearance we see for most fluid bed machines.


That's a good question -- I do have a popcorn machine that I'm upgrading from and I suppose its heater (and perhaps even the vented cylindrical wall) could be salvaged. But that still brings me back to the question of whether this ~ 1 kW heater will work for a half pound of coffee beans, or if it needs to be beefier.

The Nesco machine runs at 800 W and it can only roast a third of a pound. Honestly, that's not bad! So I wonder if a similarly built air roaster with a 1 kW heater element stolen from a popper would work slightly better.
 
renatoa
When I was in my popcorn days, my 1200W machine was been controlled by a dimmer, and I remember 600W were required for the yellowing phase of 120 grams of greens.
The maximum used was about 900W, never full power.

For half pound 1200 W could be enough, there is in Europe a very powerful popper, a Lidl brand called Silvercrest, able to bubble 230 grams of green, and roast them with 1200W, check here:

This is the machine:
https://www.lidl.de/de/silvercrest-popcorn-maker/p176819
 
ranfea
Very informative!

With my 1kW popper, I have to turn the heat down to 75% to roast 60g in a reasonable time, but the fan is maxed out and doesn't move the beans at all in the first few minutes.

I'm going to try to inject some air into my popper with a mattress fan and see how high I can go. Will report results back here.
 
eltakeiteasy
Is the Pyrex Bake A Round glass chamber really only 3.5" wide? I thought it was closer to 6".
 
renatoa
15 cm round bake ... lot of bread Grin

Nope, is 3.5", close to 9 cm glass we are using here in EU as replacement, because bake-a-round is not common.
 
CK
I recommend a small corded stick vacuum motor as your blower. It will need some type of custom housing to contain and direct the pressure it makes. Vacuum motors overcome static pressure in FB roasters.

As an example, I'm able to loft up to 1 lb of greens using a 240 watt blower with low cfm. The RC has green beans 5 1/2 inches deep, and the little vacuum motor easily overcomes resistance of heat elements, ducting and bean mass.

Leaf blowers are high speed fans that aren't designed for pressure or overcoming resistance.
CK attached the following image:
roaster_heater_and_blower_internals_r1.jpg
 
eltakeiteasy
renatoa wrote:

15 cm round bake ... lot of bread Grin

Nope, is 3.5", close to 9 cm glass we are using here in EU as replacement, because bake-a-round is not common.


I'm not sure what you are trying to say. The diagram in the first post shows the glass at 3.5" while others have said it's much larger. I am simply asking if the Bake A Round is 3.5" circumference, not the length of the tube.
 
CK
Here's the spec page from Amazon... https://www.amazo...B005BUL3XM

See question 3 in the list... there it states the inner and outer dimensions, 3 1/2 and 3 5/8 respectively. Seems to be very thin glass if that is the case.
 
renatoa
3.5" is diameter, not circumference.
3.5" is close to 9 cm we are using in Europe.
 
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