Equipment and Process Design for Small-scale Continuous Crystallization

Continuous processing and modularization offer opportunities for an enhanced resource and energy efficiency, a stable product quality and reduced time-to-market in production processes in the fine chemical and pharmaceutical industries which are conventionally based on batch manufacturing. The shift to a fully continuous production in these branches requires suitable continuous flow equipment and versatile design concepts for a variety of product properties and process conditions.
This study focusses on cooling crystallization from solution as being an important work-up and product purification method for a large variety of fine chemicals and pharmaceuticals. The design of a continuous tubular cooling crystallizer is presented, starting with a design concept followed by the manufacturing and characterization of a laboratory level prototype for the g/h scale. The equipment concept is based on horizontal helical coil tubes in the coiled flow inverter (CFI) design. The scale-up of the CFI cooling crystallizer concept to miniplant level and kg/h scale is successfully demonstrated. The developed equipment concepts and methods enable the design and scale-up of robust continuous flow tubular equipment for a variety of solid-liquid processes.