Falling film evaporators are used to concentrate liquids that do not have solids present. The Swenson falling film evaporator is an ideal solution for processing heat-sensitive liquors.
In falling film evaporators, liquid enters the top of the unit and forms a continuous film that flows down the inside of heating tubes via gravitational force. The liquid film flows downward through the tubes at boiling point. The liquid partially evaporates, concentrating the liquid.
Falling film evaporators are ideal for heat-sensitive liquids because they allow evaporation to occur with an extremely low temperature difference between the process stream and the heating element. In addition, the liquid’s residence time within the evaporator is measured in mere seconds, making it suitable for concentrating products like milk and juice that are sensitive to prolonged heat.
Falling film evaporators are typically heated using inexpensive, high-pressure steam, making them a cost-effective solution for many applications. In addition, because the circulating pumps on each effect maintain the wetted tube surfaces, these evaporators have excellent turndown capabilities.