topbanner.gif
Login
Username

Password




Not a member yet?
Click here to register.

Forgotten your password?
Request a new one here.
Shoutbox
You must login to post a message.

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!

In Memory Of Ginny
Donations

Latest Donations
JackH - 25.00
snwcmpr - 10.00
Anonymous - 2.00
Anonymous - 5.00
Anonymous - 5.00
Users Online
Guests Online: 26

Members Online: 0

Total Members: 7,370
Newest Member: Johny Morrisson

View Thread

Who is here? 1 guest(s)
 Print Thread
Fluid bed physics
Dan
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.
 
ciel-007
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
 
seedlings
Dan, did you make any contributions to the wiki page?

Thanks for posting!

CHAD
Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
 
Dan
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.
 
seedlings
I meant the specific fluid-bed section. I remember you did a fine job at the home roasting page ThumbsUp

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

Similar Threads

Thread Forum Replies Last Post
First Fluid Bed Attempt Fluidbed Roaster 22 12/05/2021 10:01 AM
New Fluid bed roaster- Design and modifications Fluidbed Roaster 12 11/23/2021 1:15 PM
Heat Gun Driven Fluid Bed Roaster Fluidbed Roaster 29 11/08/2021 3:24 AM
Simple fluid-bed roaster attempt: wiring heat element Fluidbed Roaster 4 06/14/2021 7:27 AM
My first roaster ever - a very cheap fluid bed Fluidbed Roaster 9 04/24/2021 8:43 AM
Homeroasters Association Logo, and all Content, Images, and Icons © 2005-2016 Homeroasters Association - Logos are the property of their respective owners.
Powered by PHP-Fusion Copyright © 2021 PHP-Fusion Inc
Released as free software without warranties under GNU Affero GPL v3
Designed with by NetriX