Cooling Tower | Working Principle and Types Of Cooling Tower

What is Cooling Tower

Cooling tower is an important part of power plant. The basic working principle of cooling tower is to cool the hot water with the help of atmospheric air. Though it is widely used in different engineering sector and other refrigeration plant. The height of the cooling tower in thermal power plant is about 9 feet or above from the ground level. A water store unit called pond is placed at the base of the cooling tower.In steam power plant, cooling tower first collects hot water from the condenser at a certain height from the ground level, after that the hot water falls down by the radial spray. The atmospheric air which is comparatively cool enters at the bottom of the tower.Now the hot air in the cooling tower expose in the atmospheric air which reduces the temperature of the hot water by partial evaporation. This cooled water is collected in the pond at the base of the tower and pumped into the condenser for further use. Doing so, limited quantity of water can be used again and again.It is used such type of power plant where supply of water is limited.

Some important factors which is essential for cooling tower to cool the water:-

1. Size and height of the cooling tower.

2. Temperature of the air.

3. Humidity of the air.

4. Arrangements of plate in the cooling tower.

5. Velocity of air entry of the cooling tower.

6. Accessibility of air to all parts of the cooling tower.

Types Of Cooling Tower

Types of cooling tower can be classified following categories.

1. According to the type of draught

2. According to the material used

According to the type of draught

According to the type of draught cooling tower is three types.

1. Natural draught cooling tower

2. Forced draught cooling tower

3. Induced draught cooling tower

1. Natural draught cooling tower

As we see in the above picture, the circulation of air is produced in natural draught cooling tower by the pressure difference of air inside and outside the cooling tower.

2. Forced draught cooling tower

In forced draught cooling tower, the circulation of air is produced by fans placed at the base of the tower.

3. Induced draught cooling tower

In induced draught cooling tower, the circulation of air is provided by means of fans at the top of the tower.

According to the type of material used

According to the type of material cooling tower is three types.

1. Timber cooling tower

2. Concrete cooling tower

3. Steel duct type cooling tower