How does a Falling Film Evaporator Work?

The working principle of falling film evaporators can be described as follows.

The liquid is added to the upper tube of the heating chamber of the falling film evaporator. Through the liquid distribution and film forming device, it is evenly distributed into the heat exchange tubes. Under the action of gravity and vacuum induction and air flow, it forms a uniform film from the top to the bottom. During the flow, it is heated and vaporized by the shell-side heating medium. The generated steam and the liquid phase enter the separation chamber of the evaporator. The vapor-liquid is sufficiently separated, and the steam enters the condenser for condensation (single-effect operation) or enters the next-effect evaporator. The medium is heated to achieve multi-effect operation, and the liquid phase is discharged from the separation chamber.

How to Improve the Efficiency of Falling Film Evaporator?

1. Control the amount of mother liquid added in the appropriate range: The attention should be paid to the amount of circulation for falling film evaporators with various evaporation capacities in order to ensure that the liquid film can flow steadily and evenly in the heating tubes.
2. Control the heat flow intensity: It is necessary to control the steam pressure and ensure the steady steam velocity as well as discharge the non-condensable gas continuously in order to obtain the stable heat flow intensity.
3. Selection of distributors on the falling film tubes: Distributors act as extremely important components in a falling film evaporator. The form of liquid film depends on distributors. So the selection of distributors is pretty essential. It is required to clean the distributors of falling film evaporators regularly.