Cooling Tower Types
1. Counter flow – induced or forced draft.
2. Cross flow – induced or forced draft.
In the counter flow draft – in this typical design, hot water enters at the top, while the air is
introduced at the bottom and exits through the top as warm water falls downward. Both forced and induced draft fans are used.
Because of the need for extended intake and discharge plenums; the use of high-pressure spray systems and the typically higher air pressure losses, some of the smaller counter flow towers are physically higher; require more pump head and utilize more fan power than their cross-flow counterparts.
2. In the cross-flow draft – in this special, but common design, the air flows horizontally, across the downward fall of water. The air, however, is introduced at one side (single-flow tower) or opposite sides (double-flow tower).
An induced or forced draft fan draws the air across the wetted fill and expels it through the top of the structure as the water cascades down through the tower Many cooling towers are assemblies of two or more individual cooling towers or “cells.” Multiple-cell towers as an eight-cell tower, can be lineal, square, or round depending upon the shape of the individual
cells and whether the air inlets are located on the sides or bottoms of the cells.