Components of Cooling Towers
The basic components of an evaporative tower are: Frame and casing, fill, cold water basin, drift eliminators, air inlet, louvers, nozzles and fans.
Frame and casing: Most towers have structural frames that support the exterior enclosures (casings), motors, fans, and other components. With some smaller designs, such as some glass fibre units, the casing may essentially be the frame.
Fills: Most towers employ fills (made of plastic or wood) to facilitate heat transfer by maximizing water and air contact. Fill can either be splash or film type. With splash fill, water falls over successive layers of horizontal splash bars, continuously breaking into
smaller droplets, while also wetting the fill surface. Plastic splash fill promotes better heat transfer than the wood splash fill.
Film fills – these components consist of thin, closely spaced plastic surfaces over which the water spreads, forming a thin film in contact with the air. These surfaces may be flat, corrugated, honey combed, or other patterns. The film type of fill is the more efficient and provides same heat transfer in a smaller volume than the splash fill.
Cold water basin: is located at or near the bottom of the tower, receives the cooled water that flows down through the tower and fills. The basin usually has a sump or low point for the cold-water discharge connection. In many tower designs, the cold-water basin is beneath the entire fill.
In some forced draft counter flow design, however, the water at the bottom of the fill is channelled to a perimeter trough that functions as the cold-water basin. Propeller fans are mounted beneath the fill to blow the air up through the tower. With this design, the tower is mounted on legs, providing easy access to the fans and their motors.