Collect. Czech. Chem. Commun. 1982, 47, 1189-1194

Scale-up of agitated crystallizers; Cooling batch crystallization of potassium aluminium sulphate

Jaroslav Nývlta, Piotr Karpińskib, Stanislav Žáčeka, Miloslav Karela, Jerzy Budzb and Zbigniew Narućb

a Institute of Inorganic Chemistry , Czechoslovak Academy of Sciences, 160 00 Prague 6
b Institute of Chemical Engineering and Heating Systems, Technical University of Wroclaw, Poland


The crystallization of potassium aluminium sulphate was conducted by cooling a solution saturated at 70°C to a temperature of 25°C at three various cooling rates. The measurements were performed on a small scale (160 cm3) and a large laboratory scale (0.021 m3). The mean size of product crystals was determined by sieve analysis, and the system constant, BN, was calculated using previously derived relations. The BN value is the same, within experimental error, for all the experiments and scales, indicating that agitated-vessel cooling crystallizers can be modelled successfully even on a very small laboratory scale.