crystalliser

A crystalliser is a piece of equipment used in chemical engineering and materials science to induce the formation of solid crystals from a liquid solution, melt, or gas. This process, known as crystallization, is a fundamental separation and purification technique. Crystallisers are designed to control the conditions under which crystals grow, thereby influencing their size, shape, and purity.

There are various types of crystallisers, each suited to different applications and materials. Common designs include cooling crystallisers, where supersaturation is achieved by lowering the temperature of a solution; evaporative crystallisers, which increase supersaturation by evaporating the solvent; and reactive crystallisers, where crystals form as a product of a chemical reaction. Vacuum crystallisers are a type of evaporative crystalliser that operate under reduced pressure to lower the boiling point of the solvent, allowing for crystallization at lower temperatures.

The design of a crystalliser takes into account factors such as fluid dynamics, heat transfer, and mass transfer. Agitation is often employed to ensure uniform temperature distribution, prevent settling of crystals, and promote crystal growth. The choice of crystalliser depends on the specific properties of the substance being crystallized, the desired crystal characteristics, and the scale of operation. Crystallization is widely used in industries such as pharmaceuticals, food processing, and petrochemicals for product purification and isolation.