Method of, and apparatus for the industrial production of pure crystalline natural grape-sugar (glucose, dextrose) from grapes or raisins

摘要

PICT:0465852/III/1 PICT:0465852/III/2 Grapes or raisins are extracted with water, the extract is freed from tartrates, concentrated to 40--42 DEG B., allowed to crystallize, centrifuged to obtain impure glucose crystals, and rinsed with a levulose solvent, e.g. cold water and/or alcohol, dry steam or warm air. The crystal mass is then diluted, treated with lime, concentrated and recrystallized. Further recrystallization may be effected to obtain a purer product. Anhydrous glucose is used to seed the crystallizable solutions. A crystallizing vessel comprises an elliptical vessel, Fig. 2, provided with a cold water jacket and twin agitators 50, revolving in opposite directions. The impure glucose may be rinsed on a filter cloth on a perforated disc 54 underneath which a vacuum is maintained by pipe 17, Fig. 4.