Sugar solutions entering the White Sugar Vacuum Pans in a cane sugar refinery are: fine liquor from evaporators and syrups from the previous sugar boilings. There are various ways to make the liquor / syrups management in white sugar crystallization.
One of these techniques is the three boiling system. In this system, the first boiling is made with liquor from the evaporators. Syrup from this boiling is crystallized in the second boiling. Syrup from the second boiling is crystallized in the third boiling. Sugars produced in each boiling are mixed to produce white sugar. When necessary, sugar from the first boiling is separated to produce extra white sugar .
Three Boilings Scheme
Other syrup management technique, the In-boiling System. In this system, the first boiling is made with liquor from the evaporators. In the next boilings, crystallization start with fine liquor from evaporators and after a certain level, syrup from the previous boiling is fed to the pan.
In this system, as the number of sugar boilings increases, sugar quality will decrease. When a maximum limit of sugar colour is attained, syrup is sent to the recovery station and the In-boiling system will start again with the first boiling.
In Boiling Scheme