After some research I found www.pharmaguideline.com which give working and principles of Remote Mixer Granulator and Fluidized Bed Dryer. Nice examples of cases I could have asked my students in the course Scaleup-Scaledown.
As described in the Lecture Notes, first all possible subprocesses should be considered and their potential speed estimated. Next analysis is to find the limiting subprocess at small and/or large scale (regime analysis). Etcetera. See