What’s a Falling Film Evaporator?

Print anything with Printful



Falling film evaporators are used to concentrate temperature-sensitive substances in various industries. The liquid flows down the walls of heating pipes, evaporates without direct contact with vapor, and is collected via a separator. They are commonly used in the dairy and food industries, but require careful design to prevent scale and dry patches. The system can be controlled to obtain consistent liquid concentrates with low temperature differences.

A falling film evaporator is a device used in industries to evaporate temperature sensitive substances and obtain concentrates of these substances under controlled conditions. They find application in various sectors such as the dairy, paper and chemical sectors. Falling film evaporators can also be used in the pharmaceutical and food industries.
The heat-sensitive liquid to be treated flows down in a thin film along the walls of the heating pipes, which is why it is called a falling film evaporator. The liquid substance is brought to a boil if necessary, before being allowed to enter the evaporator head. Once it enters the head, it flows down through the inner surface of the heating tubes.

The steam is applied to the outer surface of the pipes. The liquid evaporates without coming into direct contact with the vapor. In the next stage, the concentrated liquid and vapor vapor enter a separator. The liquid is collected and released via a pump.

A falling film evaporator is used to concentrate substances that tend to leave residues due to condensation. They are very carefully designed to allow liquid to flow smoothly along the surfaces of the pipes and require adequate wetting of the heating surfaces for the process to run smoothly. If the surfaces are not adequately moistened, scale and dry patches could form, which would hinder the whole process.

They are the most commonly used evaporators in many industries when it comes to concentrating heat sensitive liquids. They are used in the dairy industry to concentrate milk and skim milk without suffering heat damage. Fruit and vegetable juices are also concentrated with the aid of falling film evaporators.

It is a challenge to concentrate these substances as some elements in the juices that affect the flavor are lost during the evaporation process. Juices also contain small solids, which are left behind in the evaporation process. These solids stick to the surface of the pipes and can burn or deteriorate. This problem is avoided by controlling the system so that the fluid circulates at high speed inside the pipes. Sometimes the flavor of the juice changes as it becomes more concentrated, so some raw juice is introduced into the concentrate to ensure the flavor stays the same.

It is possible to obtain consistent liquid concentrates with the help of a properly designed control system. A falling film evaporator has a very high degree of sensitivity to changing parameters such as feed rate and energy delivery. It can work with extremely low temperature differences between the liquid to be treated and the heating medium. This feature allows a falling film evaporator to be used in multiple configurations in many industries.




Protect your devices with Threat Protection by NordVPN


Skip to content