A forced circulation evaporator is a type of evaporator used in various industrial processes to concentrate a liquid by removing its water content. Unlike natural circulation evaporators where the liquid circulates due to natural convection currents, forced circulation evaporators use mechanical means, such as pumps or fans, to maintain a consistent flow of liquid through the evaporator system.

Evaporators are devices used to concentrate a solution by removing the solvent through evaporation. Common types of evaporators include simple distillation systems, multiple-effect evaporators, and various specialized designs for specific applications. A "forced falling combined evaporator" might refer to a specific configuration or modification of an evaporator system that uses forced circulation to enhance the falling film or film-wise evaporation process, but without more specific information, it's challenging to provide detailed insights.