Because of your powder diameter size, your in the Group C of Geldart's Classification of particles. These types of powders are difficult to fluidize because of interparticle forces. Group B and A types of powders are the best for fluidization.

A batch fluidized-bed dryer may work if the solid polymer is "wet" with a highly volatile liquid but given that the polymer beads are relatively large in size, the drying operation will not be fast as is the norm in fluidized-bed drying.

Francisco Javier Sanchez Careaga Thank you for the answer!

Nizar Matar You mean the powder particle is not small enough? Then how big size is proper for using fluidized-bed dryer?

Since these particles are of size C as Professor Francisco J. Sanchez Careaga mentioned, then if drying occurs (by the method I suggested) then it will take hours instead of minutes noting that there are 2 opposing motions: the up-flow of the warm speedy air & the down-flow of particles due to gravity.

You can try using Larostat as an aditive to improve the flowability of your powder.

Minimum Fludization velocity is required in drying of products in Fluid Bed Drier.

Calculating of maximum flidization are given in attached file.