Partial Load Enabled Falling Film Evaporator and Method for Operating a Partial Load

A falling film evaporator comprising:

• an external outer shell;
• a given number of tubes the internal side of which has a liquid film flowing downwards;
• upper end devices for distributing the liquid to the individual tubes;
• lower end devices for collecting the residual liquid and the vapor;
• a vapor extracting device for withdrawing the vapor forming inside the tubes;
• a device for withdrawing the non-evaporated portion of the liquid inside the tubes;
• partitions that separate an internal chamber of the tubes and the hydraulic devices linked to said chamber, for distributing and collecting the fluids from the space enclosing the tubes;
• a device for feeding the gas/vapor mixture to a chamber enclosing the external side of the tubes;
• a device for withdrawing the condensed liquid from the chamber enclosing the external side of the tubes;
• a device for discharging the condensed vapors and the condensable gases from the chamber enclosing the external side of the tubes, wherein
• the header distributes the liquid to be evaporated among the individual internal sides of the tubes and is partitioned in at least two segments, and
• each of these segments is fed with liquid or omitted, respectively.