Cooling towers are a very important part of many chemical plants. The primary task of a
cooling tower is to reject heat into the atmosphere. They represent a relatively inexpensive and
dependable means of removing low-grade heat from cooling water. The make-up water source
is used to replenish water lost to evaporation. Hot water from heat exchangers is sent to the
cooling tower. The water exits the cooling tower and is sent back to the exchangers or to other
units for further cooling.
In cross flow induced draft towers, the water enters at the top and passes over the fill. The air, however, is introduced at the side either on one side (single-flow tower) or opposite sides (double-flow tower). An induced draft fan draws the air across the wetted fill and expels it through the top of the structure.