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12/05/2021 3:10 AM
Welcome, Johny Morrisson !

12/02/2021 6:47 AM
tahoeguy and sanakashyap220, coffee drink

12/01/2021 12:48 PM
Hey Ren, thanks for checking all the newcomers in!. You beat me to it most of the time but I am checking often. Grin

12/01/2021 6:16 AM
PGS_QLD, welcome !

11/29/2021 9:33 AM
Welcome, Andyc, coffeeswings and chuckster!

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Fluid bed physics
See the WikiPedia page on fluidized bed. Typically, fluid beds are used for very small particles. However:

"In 1973, Professor D. Geldart proposed the grouping of powders in to four so-called "Geldart Groups". The groups are defined by their locations on a diagram of solid-fluid density difference and particle size. Design methods for fluidized beds can be tailored based upon the particle's Geldart grouping:

Group D The particles in this region are above 600 um (0.6 mm) and typically have high particle densities. Fluidization of this group requires very high fluid energies and is typically associated with high levels of abrasion. Drying grains and peas, roasting coffee beans, gasifying coals, and some roasting metal ores are such solids, and they are usually processed in shallow beds or in the spouting mode (my emphasis)."

Spherocity plays a major roll in the pressure and volume needed to keep particles aloft. Coffee beans are nearly spherical, and need a lot of energy to keep them moving.
Thanks Dan. This is really cool stuff for a nephyte like me.

One of the things I really enjoy about HRO
is the fact that some highly knowledgeable members (like Dan)
are prepared to take some of their valuable time
to share some highly interesting/informative posts (like this one)
to enlighten some less knowledgeable members (like me).

Many of us visit HRO to take something away.
That would not be possible if it were not for
many generous HRO members (Dan being only one example of course)
contributing so much to the excellence of this site.

Thanks HRO!
Ciel... seeking Heaven in my cup with ................................................................................................................. EXPOBAR Brewtus II - MAZZER Mini E - MAHLK´┐ŻNIG Vario - GeneCafe - RAF-1 Extreme (Modified B-2 HOTTOP) - BellaTaiwan XJ-101
Dan, did you make any contributions to the wiki page?

Thanks for posting!

Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
Chad, Do you mean the WikiPedia home roasting coffee page? Sure, I edited it and other coffee pages extensively about a year ago. They were a mess. Take a look at the 'talk' pages for what does on behind the scenes to improve pages.
I meant the specific fluid-bed section. I remember you did a fine job at the home roasting page ThumbsUp

Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
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