Numerical study and experimental validation of the water films and the detachment of drops on drift eliminators.

Abstract

This paper is focused on the study of a type of drift eliminator installed in a mechanical draft cooling tower. Drift eliminators are installed in cooling towers in order to avoid water droplets to be emitted to the ambient. These droplets are formed by the crossflow between airflow and water pulverization inside the tower. The study is centered on the analysis of three aspects: the water film formed on the plates of the drift eliminator, the size of water droplets detached from this film and the flow conditions for the detachment of these droplets. These aspects are studied with a multiphase numerical approach, validated by experimental tests. Good agreement is obtained between numerical and experimental results. The study shows that the behavior of water droplets is very influenced by air velocity inside the cooling tower. Moreover, limits for air velocity are set for the drift eliminator not to act as a droplet generator itself.