The use of falling-climbing film evaporator for concentration of indigenous orange juice

Fruit juices are among heat sensitive foods. Vitamins, proteins and other organic materials present in most fruit juices may be easily decomposed during heat processing. Therefore, evaporators with minimum residence time and maximum efficiency for concentrating fruit juices should be applied. So,tubular type falling and climbing film evaporators are suitable devices. In the present investigation, certain important factors in concentration of in digenous orange juice from north region of Iran in a pilot-plant double effect falling-climbing film evaporator have been studied. Variation of liquid film tickness, heat transfer coefficient, hydrodynamic and thermal properties show that evaporation of the fruit juices take places in turbulent regime and required concentration and ratio of the product concentration to acidity can be achieved by six stages evaporation.