Calculation method for designing a multi-plate freeze-concentrator for concentration of fruit juices

► To establish a calculation method for sizing an equipment for film freeze-concentration. ► The proportion of sugars in the juice and °Brix are known. ► The flow of juice and heat flux are fixed. ► It can be obtained: ice (kg, °Brix), concentrate (kg, °Brix), and process (time, m2 exchange). ► It can be used to analyse the economic viability compared to alternative processes. The aim of this work is to establish a calculation method for designing and sizing of equipment for film freeze-concentration of fruit juices. The various steps are outlined of an algorithm that uses the characteristics of the juice as inputs. The calculation method assumes that the amount of fruit juice, its concentration (°Brix), and its sugar composition (% of fructose, glucose and sucrose) are known. Using pre-set (constant) values for the flow of concentrated juice and for the heat flow, the algorithm predicts the values of the main unknowns: the concentration of impurities in the ice, the concentration of sugars in the final concentrate, the heat-exchange surface needed, the amount of ice obtained, and the duration of the concentration step. Using this calculation method, one can estimate the size of the equipment and its operational costs, which can be used to analyse the economic viability compared to alternative processes.