Optimization of juice purification by inline-online registration of the raw juice quality

On-line viscosity measurement of the raw juice offers the possibility of managing the processing of deteriorated and frost-damaged beets with high fractions of colloidal substances such as dextran, levan and pectin. The processing of deteriorated beets, which involves an increase of the levan and dextran contents in the raw juice, as well as efforts to reduce lime consumption, motivated the investigation of a rapid method of detection in order to register variations in the high-molecular components in the raw juice. To this end, the online rheometer Rheoswing(R) RSD 1-1 was employed as online measurement device since it provides evidence of changes in the viscosity of the raw juice in consequence of the changed concentration of high-molecular components in the raw juice and other structural changes within the various process stages of sugar manufacturing. Modem rheological methods of analysis for the continuous registration of raw juice viscosity show that raw juice viscosity can serve as a possible guidance parameter for regulating the quantity of milk of lime in main liming or setting the main liming alkalinity. Determination of the raw juice viscosity allows early identification of the prejudicial effect of a poorly filterable first carbonation slurry and to counter it by changing the main liming alkalinity. This paper reports on the studies conducted by the central research, development and services department, and in the factories of Sudzucker, in the 2002-2005 campaigns.