Cooling tower is used to:

Wet Cooling Towers

Dry Cooling Towers

• In wet cooling towers, water is sprayed on fills or packing. Fill mixes falling water with air. Air enters through louvres. This mixing results in heat transfer, which cools the water.
• The minimum temperature to which water can be cooled is the adiabatic saturation or wet-bulb temperature of the ambient air.
• The cooled water is collected in the basin at the bottom, from where it is pumped back to the condenser.

• Dry cooling towers are employed where cooling water is not available in plenty, even for the use of makeup.
• In a dry tower, warm water from the condenser flows through the finned tubes over which the cooling air is passed. Heat is rejected to the air as water is cooled.