Tests of the BMA B 1750 white sugar centrifugal in the Wierthe sugar factory during the 1998 campaign demonstrated that a newly designed syrup separation device produced a wash runoff of markedly better quality without a significant decrease in its quantity. Separation of the green and wash runoffs, which was carried out at the end of washing, showed that the amount of mother liquor, which inevitably is present in the wash runoff, could be reduced by half, compared with conventional syrup separation. With optimal separation, only about 5% of the mother liquor was found in the wash runoff, and it was possible to considerably improve the quality in respect of purity, colour and ash. The new separation device offers an advantage to sugar factories operating a boiling scheme with wash runoff recycling, as it reduces the recycled nonsugars in the corresponding crystallization stage. On the other hand, the new development shows no further benefit in a boiling scheme without wash runoff recycling, since such a scheme does not distinguish between green and wash runoffs and just a collective runoff reaches the subsequent crystallization stage.
pdf download: 2000-501-507.pdf