cooling tower

A cooling tower is a specialized heat exchanger in which air and water are brought into direct contact with each other in order to reduce the water's temperature.A small amount of water evaporates taking away heat which is being circulated 

Types of cooling towers

1.Classification based on air flow generation method

   (a)Natural draft-Due to temperature difference there is density difference.Due to density difference there exists buyancy. warm air is less dense than drier air at the same pressure. This moist air buoyancy produces an upwards current of air through the tower.Fresh cool air is drawn from bottom.   .

(b)Mechanical draft-Uses external source for forced  air flow.For this power driven motor is utilized

2.Classification based on heat trabnsfer method

   (a)Dry cooling towers

  (b)wet cooling towers

   (c) Fluid coolers