Natural-draft Cooling Tower

Natural-draft cooling towers and one of two intake screens and associated pumps for the Tennessee Valley Authority, Sequoyah Nuclear Power Plant, Tennessee. Natural-draft tower airflow is drawn through the packing or fill (distributed at the base) by means of the small density difference between the warm moist air inside the tower and the cooler ambient air outside the tower (Stultz and Kitto, 1992). Because of the small temperature and density difference, these cooling towers tend to be tall. These towers are relatively open cylindrical structures. Modern units are sometimes referred to as hyperbolic towers because of their shape. The heat rejected from the steam to the cooling water is circulated through the cooling tower where the heat is rejected to the atmosphere as latent and sensible heat.