Increasing our understanding of supersaturation and the use of massecuite dry substance in pan control – part 2

Part 1 of this study calculated the supersaturation and mother molasses dry substance for a range of operations typically experienced during the run-up and heavy-up phases of the boiling of high-grade seed massecuite, and A, B and C massecuites. Correlations for the solubility of pure sucrose, solubility coefficient for cane syrups and molasses, and boiling point elevation were used. Further investigations are undertaken to understand the operating range for mother molasses dry substance in the growth zone between near zero growth rates and high growth rates, where nucleation is likely to occur. In addition, the sensitivities of the supersaturation of the mother molasses to rapid changes in the head-space pressure and to changes in the sucrose solubility as a result of a change in the RS/ash ratio are examined. The investigations are extended to include using massecuite dry substance for the control of the run-up and heavy-up phases for the various pan boiling duties. These data provide suitable operating ranges for massecuite dry substance transducers, such as microwave transducers. The results from this paper are applied in Part 3 of this study, where the profiles for massecuite dry substance are examined for the various pan boiling duties undertaken in the three massecuite flowscheme adopted by Australian factories.