Coffee Bean Sizing
Eduardo: My appreciation for your kind words and we must also thank all of our participants who ask the interesting questions and answer many from their own experiences, especially our buddy John.
I must admit my experience in coffee sizing is limited to the local donut/coffee shop and if that is considered experience, well then I am an expert!
I found some interesting links for this job though:
SEPERATION AND SIZING OF FOOD is an expertise of its own:
Typically, the mode of vibration is GENTILE and recipricol type of sizing, (gentle sweeping, side to side motion) and the sizing for coffee beans is in the 64ths of an inch type of sizing range. These screening/separation devices I would assume to be in the ROTEX or SIFTER style of vibrating screener families.
SOME pertinant LINKS for sizing of coffee beans:
http://www.coffeeresearch.org/coffee/screen.htm
This site above seems to have a fair bit of info on your needs, hope this might help. ■
Re: What Do I Need?
Thanks for your reply George, and of course my regards for everybody that makes this such an interesting and useful forum.
I decided to design an inclinated vibratory screen, because the coffee bean before it's toasted it's pretty hard, and I think it will resist the force of the screening. The dimensions of the screen will be 1500mm X 2000mm because it's for a cooperative of Tzeltal indigenous producers of coffee from Chiapas (and this is why also I have to reduce all the costs if possible), and they haven't more room to put it, so I will calculate the capacity in the reverse way. Indeed the apertures goes from 19/64" to 14/64", but I have a doubt with the height of the screen, because here recomend that the distance between the decks won't be more than 4 times the aperture of the mesh (is this rigth?), so my total height would be of 6" ? It seems too short, don't you think? And at last, which forces do I have to consider to calculate de thickness of the side and back plates?
Thanks you a lot
Eduardo Balvanera
Ps. sorry for my poor english ■
Distance Between Decks
Distance between decks can be from 9" up to 15" or more depending on the size of the material being screened or scalped.
Eduardo: I believe you are confusing BED DEPTH of material guidelines with distance between the sideplates.
BED DEPTH: this rule from VSMA states: material depth on the screen at the discharge end of the screen deck......should not exceed 3-4 times the size of the opening in the wirecloth...to ensure we are screening EFFICIENTLY. ■
Re: What Do I Need?
Thanks George, you are rigth, I was confuse, but now I understand this.
Eduardo Balvanera ■
Eduardo
How are you making out designing your new screen?
Give us an update. ■
Screener For Sale In Texas
I know of a Westrup screen machine that was used for coffee grading into 3 sizes for sale. ■
What do I need?
Before nothing, I want to congratulate Mr. George Baker by his interest in spreading the knowledge.
I want to design a vibratory screen and thanks to this forum, I decided to order the vibrating screen handbook and Im waiting that arrives. I want to collect all the information necessary of the product to sift. The machine its thought for coffee grains and I need to separate them in 5 sizes, and I need like 1/2 ton per hour. ¿Which is the information that I need to be advancing?
Thanks a lot
Eduardo Balvanera ■