Development of a Novel Supersaturation Monitoring System in Continuous Crystallization of KAl(SO 4 ) 2 ·12H 2 O

Continuous crystallization via indirect cooling of potassium aluminum sulfate dodecahydrate (KAl(SO 4 ) 2 ·12H 2 O) was carried out using a draft tube‐type crystallizer with a circulation flow path. The crystallizer was equipped with a newly designed system to monitor the degree of supersaturation in the circulation channel. The average degree of supercooling and growth rate were measured. The crystal growth rates calculated by the population balance model and the supersaturation monitor were different but close. The average supersaturation calculated from the supercooling degree and the solubility data in the literature was 0.19 g per 100 g H 2 O. This system is also expected to be applied to industrial crystallization where impurities are present.