WET COOLING TOWER

UNIT OPERATION 3

PREPARED BY: CANOY, CLAIRE E.YR & SEC. : 2B2-CHEMICAL ENGINEERING TECHNOLOGY

WET COOLING TOWER

● Wet cooling towers are heat removal devices used to transfer waste heat from industrial and other processes to the atmosphere.

●They are used primarily to provide circulating cooling water in large industrial facilities.

OPERATION

The warm water returns to the top

of the cooling tower and trickles

downward over the fill material

inside the tower. 

As it trickles down, it contacts the fan-induced upward flow of

ambient air.

OPERATION

That contact causes a portion of the water (E)

to evaporate into water vapor that exits the tower as part of the

water saturated air.

OPERATION

A small amount of the water also exits with the air

as entrained droplets of liquid water called drift

losses (D).

OPERATION

The heat required to evaporate the water is derived from the water

itself, which cools the water back to the original basin

water temperature and the water is

then ready to recirculate.

OPERATION

The evaporated water leaves its dissolved salts behind in the

bulk of the water which has not

been evaporated, thus raising the salt

concentration in the circulating cooling water.

OPERATION

To prevent the salt concentration of the

circulating water from becoming too high, a portion of

the water, referred to as blowdown(B, is

drawn off for disposal.

OPERATION

Fresh water make-up (M) is supplied to the tower basin to

compensate for the loss of evaporated

water, the drift loss water and the blowdown

water.

OPERATION

ACTUAL AIR-TO-WATER FLOW ARRANGEMENTS

AIR-TO-WATER FLOW ARRANGEMENTS

APPLICATION

● A cooling tower serves to dissipate the heat into the atmosphere where wind and air diffusion spreads the heat over a much larger area than warm water can distribute heat in a body of water.

● Industrial cooling towers is to reject the heat absorbed in the circulating cooling water systems used in industrial facilities such as petroleum refineries, natural gas treating plants, petrochemical and other chemical plants, and electric power plants (both thermal and nuclear).

APPLICATION