Effect of initial concentration of solution and coolant temperature on a new progressive freeze concentration system

摘要

Progressive freeze concentration (PFC) is believed to be able to overcome the weaknesses of conventional suspension freeze concentration (SFC), in which among all, can reduce the capital cost involved. PFC produces ice crystals as a single ice block instead of a suspension of small crystals in the mother liquor, hence reducing the number of unit operations to separate the crystals from the concentrated solution. The design of the heat exchanger where crystallization of ice should occur is among important factors in ensuring a PFC process with high efficiency. A new apparatus called crystallisation chamber (CC) for the purpose of crystallisation of ice has been designed in this research, made of copper and helical in shape. The effect of two operating conditions on the performance of the newly designed crystallisation chamber was then investigated, which are the initial concentration of solution and coolant temperature. Effective partition constant, K, was used as an indication of the system efficiency, calculated from the volume and concentration of the solid and liquid phase.