Induced Draft Cooling Tower: Working, Applications, Advantages

A cooling tower works as a heat sink. It removes the useless heat from the desired equipment to the atmosphere by cooling the water flow to a low temperature. The cooling towers have two major types: mechanical draft cooling tower and induced draft cooling tower. The mechanical draft tower is the most famous cooling tower than the natural draft tower. The induced draft cooling tower is one of the famous mechanical draft cooling tower types. This article explains the induced draft cooling tower working, components and applications.  

What is an Induced Draft Cooling Tower?

An induced draft tower is a cooling tower that contains various electric fans installed at the top of the tower.

The tower fan blows air against the flowing water around the wood planks or spatula. Water flows in the opposite direction of airflow, so the hot water meets moist air at the top, and cold water meets dry air at the bottom. This process helps to improve the heat transfer efficiency of induced draft cooling towers.

Induced Draft Cooling Tower

The induced draft cooling tower is available in a square or round shape. These types of cooling towers have static collectors or sprinklers for the water distribution process.

Working of Induced Draft Tower

An induced draft cooling tower contains fans, a spray distribution header, baffles, and a drift eliminator. An induced draft tower completes the cooling process in the below-given way:

Induced Draft Cooling Tower Working

  • The spray distribution header sprays the incoming cooling water throughout the cooling tower. This spray distribution header guides the injected water in a downward direction toward the deflector to increase the contact time between water and air.
  • The tower contains a cooling water fill. It is utilized to gain the highest heat exchange surface. The “cooling water fill” is most commonly made of PVC, metal, wood, or other materials. The “louvres” is used to suck the Air into the cooling tower.
  • The cooling tower also contains multiple large fans. The large fan introduces the cold air into the baffle area and cools the water.
  • It contains a drift eliminator which is used to stop the water droplets from becoming stuck in the exiting airflow.

Induced Draft Cooling Tower Components

The induced draft cooling tower has the following components:

  • Drift Eliminator
  • Spray nozzles
  • Fan
  • Basin
  • Casing/Shell
  • Piping
  • Fill

Difference Between Forced Draft and Induced Draft Cooling Tower

The main difference between forced draft and induced draft cooling towers is the installation location of the fans that suck air from the atmosphere.

The fan of the forced draft towers is located at the bottom and outside of the tower to allow air to circulate from the bottom to upward. However, the fan of the induced draft tower is positioned at the top just above the eliminator, which allows the air to circulate from the head of the tower to the bottom.

A sharp difference between the Forced draft cooling tower and the Induced draft cooling tower is given below:

Induced Draft TowerForced Draft Tower
It has more efficiency than the forced draft tower.It has less efficiency.
This tower consumes low power (50%) than the forced draft tower.It consumes a high amount of energy which increases the utility bill cost.
The top of this tower installs at the top.The fan of this tower installs at the bottom.
The installation of a fan at the top of the tower generates low air pressure.The installation of a fan at the bottom of the tower generates high air pressure.
This design requires less motor power.It requires more motor power.
They use only axial pumps.They use both centrifugal and axial pumps.
The induced draft cooling tower requires low space for installation.The forced draft cooling tower requires a large space for installation.
It has easy maintenance and installation.It has complex maintenance and installation.

Advantages of Induced Draft Cooling Tower

The induced draft cooling tower is more economical and efficient than other cooling towers. It has the following major advantages:

  • It has high flexibility
  • It is economical
  • These types of mechanical draft towers require low maintenance.
  • They have easy maintenance.
  • They have easy installation.
  • The induced draft tower has lower noise than other mechanical towers.
  • They have the flexibility to any water flow.
  • They have the ability to deliver high thermal efficiency.
  • These towers deliver outstanding protection against the icing of the moving parts.
  • They have constant airflow irrespective of ambient air temperature
  • They are compatible with different materials such as steel, concrete, FRP, and wood.

 Induced Draft Cooling Tower Features

  • This type of cooling tower has a low low-absorbed capacity.
  • It generates more noise than the forced draft cooling tower.
  • It needs a very small area for installation.

Applications of Induced Draft Cooling Towers

  • Data Center: The data center produces a large amount of heat during the operation of the different PCs and servers. These centers contain a cooling tower to remove this heat.
  • Power Plants: These types of cooling towers are usually used in a power plant to expel the heat produced by the steam turbine and other machines.
  • Chemical Plants: These towers are also employed in chemical plants to remove heat from different chemical reactions such as crystallization, distillation, and polymerization.
  • Oil Refineries: The induced draft cooling towers are also most commonly used in oil refineries to expel heat produced during different activities, such as cracking and distillation. It helps to maintain the temperature of the process machine within a safe range.
  • HVAC System: The HVAC system uses the induced draft tower to reduce the water temperature used for air conditioning. It helps to improve the AC system efficiency.
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