AUSTRIAN EXPERIENCES WITH SUGAR MANUFACTU RE FROM NONPURIFIED BEET JUICES

Because of the articles dealing with sugar manufacture from nonpurifie d raw juice, published until recently, we will present the experiences made on this subject in Austria which were for the time being publish ed only in part. Part one gives the results obtained from a project of a combined production of white sugar and ethanol. The idea was to con centrate raw juice followed by crystallisation (Evaporation crystallis ation). The runoff of this crystallisation step was intended for alcoh ol production, whereas the sugar was processed to white sugar (melted liquor purification,multistep crystallisation). Concentrating of raw j uice was initially impeded by scale formation on the evaporator tubes (deterioration of k-value). The situation could be improved by the add ition of small amounts of soluble Ca-salts. The ''raw juice sugar'' ob tained from the concentrate showed purities of 97-98%, but was turbid. Liming and carbonatation of the dissolved sugar gave melted liquors f rom which in three steps white sugar could be crystallised. The filtra bility after liming and carbonatation depended largely on the quality of the ''raw juice sugar''. Additional experiences with the workup of nonpurified beet juices were gathered in the production of ''Vollzucke r''. The problem of encrustation on concentrating was overcome by empl oying a special evaporator type - a metallic particle fluidized bed ev aporator with flash evaporation. The syrup thus obtained has a shelf l ife of years, provided a certain dry substance range is kept and the h eadspace is filled with protective gas. A free flawing product can be obtained by means of spray drying, but in this case the content of glu cose and fructose must not exceed certain limits. Even though an optim um separation of pulp particles and turbid material by separator was i ntended due to quality requirements, no totally blank concentrates wer e obtained. This held also true for a trial lot of sugar, obtained by evaporation crystallisation of the aforementioned concentrates.