This unit consists of two falling-film shell-and-tube evaporators and of a shell-and-tube condenser; the first stage is heated by steam, whereas the second stage is heated by the solvent vaporized in the first stage. The evaporator is fed by a metering pump and it works under vacuum thanks to a liquid-ring vacuum pump. The concentrated product and the vaporized solvent are collected into two glass tanks. The automated version is equipped with 2 PID controllers that enable to control the flow rate of steam reaching the evaporator, the vacuum degree in the system and the level of the first stage, automatically.