Cooling tower

A large tower or stack that is used for heat exchange of once-through cooling water generated by steam condensers. Hot water from the plant is sprayed into the top of the tower and exchanges heat with the passing air as it falls. The water is then collected at the bottom of the tower and used again. A small amount of water is lost (consumed) through evaporation in this process. See cooling water or once-through cooling.


Source: Corrosion-Doctors.org

Wikipedia:  https://en.wikipedia.org/wiki/Cooling_tower