Concerning quality aspects, better results for equivalent operating
conditions were achieved in the top spray experiments.
Probably due to the small particle concentration of wet particles
in the vicinity of the nozzle with regard to the bottom spray configuration.
Besides, the flow rate in the fluidization/coating step
should be high enough to keep fluidization velocity above 1.5 the
minimum fluidization velocity (umf) to provide a good mixing and
obtain a uniform distribution of the coating material in the whole
bed of particles.