4.2 MSZW in membrane-free operation.
The measured MSZW data of thiourea aqueous solution in membrane-free
cooling crystallization under different cooling rate and stirring rate
were listed in Table S1 as supporting materials. The measured MSZW data
were calibrated using the least-squares method, which is,
\(\Delta T_{\max}=40.9\times\nu^{0.2625}{N_{r}}^{-0.4757}\),
R2=0.964 (26)
Comparison of experimental MSZW data and fitted ones also provided as
supporting materials in Figure S1. According to the classical nucleation
theory, high stirring intensity will accelerate the probability of
particle collision to generate nucleation. It can also be seen that the
MSZW tend to increase with the increase of the cooling rate due to the
existence of the induction period. MSZW results provide the operation up
limit for both membrane-free operation and membrane involved operation.
MSZW under the membrane involved operation will be definitely lower than
that of the membrane-free crystallization due to the inducing nucleation
function of membrane. In this work, the rotating speed was set at 200
rpm to avoid the sever crystal breakage and secondary nucleation.