Dear Rafi, Please find below address:

http://www.fao.org/docrep/t1838e/t1838e0u.htm

Also, Please see this,

Measurement of Average Moisture Content and Drying Kinetics

for Single Particles, Droplets and Dryers

Mirko Peglow, Thomas Metzger, Geoffrey Lee, Heiko Schiffter, Robert Hampel,

Dear Raffi, please click on the link http://www.cigrjournal.org/index.php/Ejounral/article/viewFile/1091/1172

good luck !

http://science.sciencemag.org/content/48/1228/48

Article Theoretical Model for Predicting Moisture Ratio during Dryin...

As far as I think, drying rate is the rate of moisture transfer per unit time.

This information will be helpful for you.

Drying rate can be calculated as the amount of moisture lost per unit of drying surface area per unit of drying time.