Air-water experiments (cold-flow experiments) were performed for the liquid distributor of an industrial falling film evaporator (FFE). The feed to the FFE is superheated and a flash evaporation occurs in the head of the FFE. The aim of the experiments was to investigate the vapor-liquid flow in the head and the resulting liquid distribution to the evaporator tubes. Several different designs of the distributor were investigated and explanations for the performance losses of the real evaporator over time were found. Several measures were finally concluded and also implemented for the real FFE.