Abstract
The concept of the metastable zone or supersolubility was proposed some hundred years ago. The metastable zone width (MZW), the magnitude of the metastable zone, is usually determined as a degree of supercooling at which a first nucleation event is detected on cooling of a solution of a given concentration. It has been long believed that a crystallizer can be operated safely without any nucleation at any supercooling within the metastable zone. It is a question whether this concept can be used really for the design and stable operation of a crystallizer. In this study, it will be explained why the value of the metastable zone width depends on volume and cooling rate. And it will be also shown that the concept of metastable zone can be hardly applied for the design and optimal operation of a crystallizer as opposed to the common belief.
