At the end of this module, you will be able to:
The evaporation process is commonly used in the food industry to concentrate liquid foods such as milk, orange juice, and apple juice. This process is carried out either in a single-effect evaporator or multiple-effect evaporator. In this module, you will learn how to determine the operating conditions of a single-effect evaporator by conducting heat and mass balances. In the following video, you will view the movement of steam and liquid food streams through a single-effect evaporator.
As you noted in the above video, the liquid food stream is heated by steam under low-pressure conditions. The low pressure causes the liquid to boil at a low boiling point. Steam and the liquid food stream do not come into direct contact with each other; the heat exchanger wall separates them. In the next video, we will conduct a mass and energy balance for a single-effect evaporator. This analysis will provide expressions to determine flow rates, rate of heat transfer, and steam economy.
Recap
In this module, you learned how steam and product flow inside a single effect heat exchanger. We conducted a mass and energy balance on an evaporator to obtain information required for designing the process.