PSD does not use nozzles or discs to atomize. The liquid or paste to be atomized, is injected through a 6 to 10 mm internal diameter pipe, for 70 to 1.000 kg/h wáter evaporation sprays. Any solid under this size, will not stop or reduce atomization.
In the other hand, if the particle is several mm size in three dimensions, it may happen that will not totally dry inside. For example, a particle of 3x2x1 mm would completely dry in the spray. A fiber of about 6 mm long and 1 mm diameter, would also dry correctly. But a particle of 3x3x3 mm can leave with some moisture in its core.