In the production of polybenzimidazole (PBI) particles from a solution of the PBI polymer, the solution is pumped through multiple orifices into air and directed into a coagulant or non-solvent for the polymer. When employing conventional sprayers, the formed particles are irregular in shape, have a large or unacceptable particle size distribution, and have a non-uniform interior surface due to air inclusion.
Further, if the extrusion orifices of the conventional sprayer are arranged in tiers, the particle size distribution of the formed particles is substantially increased due to the uneven and lesser rate of flow of the solution through the orifices of the upper tier as compared to the solution flow through the orifices of the lower tier. Moreover, the size of the orifices of conventional sprayers cannot be readily adjusted to provide a controlled particle size distribution.