Crystallization with double-effect evaporation

An obvious advantage of continuous evaporating crystallizers with stirring systems is the possibility to operate at very low temperature differences. This enables the design of equipment for a crystallization scheme providing a double-effect evaporation: The vapour from the evaporating crystallizers for raw sugar and after-product is the heating medium for the white sugar evaporating crystallizer. Model calculations are introduced and the consequences of such lay-outs for the evaporating station and the power plant of a sugar factory are described. Accordingly, the sole production of white sugar of EEC quality 2 results in operational steam requirements of 15.3 kg/100 kg beet. Just in time for the 1994 beet campaign such lay-outs and equipment for a crystallization with double-effect evaporation have been installed in the sugar factories of Güstrow and Klein Wanzleben. Güstrow sugar factory has already started operation during the 1994 beet campaign. The report gives a survey of the operating conditions and results.