When carrying out measurements of cooling crystallization in crystallizers in different sugar factories it was found, that supersaturation diminishes at cooling rate of 1 ti 2 K/h in initial phase. It is only at low temperatures that supersaturation rises gradually. The crystallization rate is low at supersaturations ranging between 1.06 and 1.15. On average it amounts to less than 15 mg/(m2.min). Crystallization periods thus extends to 35 to 40 h. Optimization of the cooling curves is only possible if the crystallization rates are known.

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