| 摘要 |
In purifying a sugar solution, e.g. screened raw washings (affination syrup) diluted with sweet water, it is passed, at an elevated temperature, e.g. 180 DEG F., downwardly through an ion-exchange column charged with a strong cation exchange resin in monovalent salt form, e.g. particles of the sodium salt of a sulphonated polystyrene resin crosslinked with 8% of divinyl benzene ranging, in size, between 16 and 50 U.S. Standard mesh. The ion-exchanged effluent is collected, and the column is regenerated with an upwardly flowing regenerating solution, e.g. a 10% solution of sodium chloride. The ion-exchanged sugar solution, still at the elevated temperature, is then passed downwardly through on ion-exclusion column charged with a specially selected strong cation-exchange resin in monovalent salt form, e.g. particles of the sodium salt of a sulphonated polystyrene resin crosslinked with 4% of divinyl benzene ranging, in size, between 35 and 70 U.S. Standard mesh. Hot water, e.g. at 180 DEG F., is then passed downwardly through the ion-exclusion column. The effluent from this column is separated into fractions, namely a waste fraction which is discarded, an impure fraction similar to the effluent from the ion-exchange column, the required purified sugar solution, a dilute sugar solution and, if desired, a final waste fraction which is also discarded. More ion-exchanged sugar solution followed by said impure fraction, then by said dilute sugar solution and water, all at an elevated temperature, e.g. 180 DEG F., are then passed downwardly through the ion-exclusion column and the effluent is separated into fractions corresponding to those mentioned above, care being taken that substantial remixing of fractions does not occur. The above operations are repeated. The volumes of ion-exchanged sugar solution and hot water fed into the ion-exclusion column may be controlled by a differential level-detector therein. The effluent from the ion-exclusion column may be separated into fractions by instruments measuring density and electrical conductivity, which activate electric switches actuating valves in an effluent pipe and divert the fractions to their destinations, only one valve being opened for a given combination of density and conductivity.ALSO:In purifying a sugar solution, e.g. screened raw washings (affination syrup) diluted with sweet water, it is passed, at an elevated temperature, e.g. 180 DEG F., downwardly through an ion-exchange column charged with a strong cation exchange resin in monovalent salt form, e.g. particles of the sodium salt of a sulphonated polystyrene resin crosslinked with 8% of divinyl benzene ranging, in size, between 16 and 50 U.S. Standard mesh. The ion-exchanged effluent is collected, and the column is regenerated with an upwardly flowing regenerating solution, e.g. a 10% solution of sodium chloride. The ion-exchanged sugar solution, still at the elevated temperature, is then passed downwardly through an ion-exclusion column charged with a specially selected strong cation-exchange resin in monovalent salt form, e.g. particles of the sodium salt of a sulphonated polystyrene resin crosslinked with 4% of divinyl benzene ranging, in size, between 35 and 70 U.S. Standard mesh. Hot water, e.g. at 180 DEG F., is then passed downwardly through the ion-exchange column. The effluent from this column is separated into fractions, namely a waste fraction which is discarded, an impure fraction similar to the effluent from the ion-exchange column, the required purified sugar solution, a dilute sugar solution and, if desired, a final waste fraction which is also discarded. More ion-exchanged sugar solution followed by said impure fraction, then by said dilute sugar solution and water, all at an elevated temperature, e.g. 180 DEG F., are then passed downwardly through the ion-exclusion column and the effluent is separated into fractions corresponding to those mentioned above, care being taken that substantial remixing of fractions does not occur. The above operations are repeated. The volumes of ion-exchanged sugar solution and hot water fed into the ion-exclusion column may be controlled by a differential level-detector therein. The effluent from the ion-exclusion column may be separated into fractions by instruments measuring density and electrical conductivity, which activate electric swtches actuating valves in an effluent pipe and divert the fractions to their destinations, only one valve being opened for a given combination of density and conductivity. |
