The Counterflow Cooling Tower: A Quick Intro

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The counterflow cooling tower is a type of cooling tower design that offers the maximum thermal performance for its area of occupation. The fill media is horizontally installed beneath the hot water distribution basin, and the cooling process is carried out as the air passes through the fill absorbing the heat from the water flowing down the fill.

The direction of the process water stream is opposite the airflow; hence, the the name for the design. The fan is usually located above the water distribution nozzles that pulls the air through the fill media (Induced draft). It could also be installed at the air inlet section to push in the air inside the tower (forced draft). The cooled process water would drain from the fill down to the cold water basin at the bottom of the tower.

Linquip, as a reliable supplier of cooling tower products provides you with various choices of counterflow cooling tower products in order to meet your application requirements. To read more about the cooling parts and their function visit our post here.

counterflow cooling tower structure — Image from KOBELCO ECO-SOLUTIONS

Crossflow Cooling Tower Diagram and Design

As can be seen from the diagram below, the process water is pushed down the fill media in the opposite direction of the airflow. Since the airflow, in this manner, could disrupt the flow of water down to the cold water basin, the process water is brought to the nozzles through pressurized pipes to prevent back-flow of the water into the nozzles.

In this design, the air is sucked into the tower due to the pressure gradient imposed by the fan at the top of the tower, through the louvers located above the cold water basin. Since the whole horizontal cross section of the tower is dedicated to the distribution of the process water, this design becomes space-efficient.

counterflow cooling tower flow diagram — Image from KOBELCO ECO-SOLUTIONS

Working Principle

The working principle of the counterflow cooling tower is no different than what is generally true regarding cooling towers: Increasing the water surface area as it flows through the fills and water cool down via convective heat transfer to the passing air.

Crossflow Cooling Tower Parts

Pressurized piping: the process water enters the counterflow cooling tower through a header that takes pressurized water at the nozzles. that convert the water flow into droplets.
Spray nozzles: when the water reaches the nozzles, they spray the water down onto the fills.
Fill: panels onto which the water is sprayed and cascaded to increase its surface area and be interacted with by the cooling air sucked into the tower through the fill.
Cold water basin: the container placed at the bottom of the tower to accumulate the water cooled down through the fill media.
Fan: A device placed at the top of the crossflow cooling tower to induce airflow across the fills.
Air inlet louvers: air passages into the tower that keep outside bodies such as birds to from entering the tower and prevent splashing out the cooling tower water.
Drift Eliminator: panels made from materials similar to that of fills in order to prevent water droplets entrained in the air stream (drift) to leave the tower, and therefore, prevent process water loss. They are located above the nozzles and below the fan for the counterflow cooling tower design.
Float: a device that regulates the process water level lost due to drift.
Makeup water inlet: where the amount of water needed for maintaining proper process water levels in the basin, enters it.
Water outlet: the exit port for cooled down process water.
Overflow: a means of releasing extra levels of water in the basin.
Drain: a component to control the amount of mineral content in the basin accumulated during the operation cycles.

Advantages of the Counterflow Cooling Tower

These types of cooling towers are perfect for cooler environments where there is a chance of icing which is detrimental to the health of the device and its performance. The counterflow cooling tower requires lower pump head and power consumption. In addition, they require minimal maintenance and have high performance. The chance for fouling film and splashing from the fills is also low. Finally, as was stated before, they require less space compared to the amount of cooling they provide.