7 - Crystallizer design and performance

Abstract

This chapter provides an overview of crystallizer design and performance. Tailoring of the particle size of the crystals from industrial crystallizers is of significant importance for both product quality and downstream processing performance. The scientific design and operation of industrial crystallizers depends on a combination of thermodynamics—which determines whether crystals will form, particle formation kinetics—which determines how fast particle size distributions develop, and residence time distribution–which determines the capacity of the equipment used. The chapter provides information about the design and performance prediction of both batch as well as continuous crystallization. Batch crystallizers are very commonly the vessel of choice or availability in such duties as the manufacture of fine chemicals, pharmaceutical components, and specialty products. The design of the batch crystallizer has three main important aspects: vessel sizing, operating policy, and performance measures. Continuous crystallizer design is highly developed using the population balance approach. The crystallization kinetics and design equations are helpful to calculate the crystallizer residence time and the vessel volume required to achieve a given mean product crystal size.