There are many different designs and types of cooling towers. They range in scale from that of Kalisindh Thermal Power Station in India (202 meters tall), to the 3-meter tall portable cooling towers that are very popular with small and medium enterprises (SMEs).
Interestingly, the materials used in cooling towers varies. Until recently, Redwood was used, but now manufacturers use more modern, synthetic materials.
If you’re maintaining a cooling tower or want to upgrade your existing tower – or maybe buy a new one – it’s important to have a basic knowledge of the different parts and components. Here are the main categories of parts that are standard in cooling towers for businesses.
Plate Heat Exchangers (PHEs)
Most people would not associate plate heat exchangers with cooling towers. However, adding a PHE to your cooling tower setup can increase efficiency and lower the overall cost of running the tower. This combination will probably be the future of cooling towers for small and large enterprises.
Usually a PHE is external to the main cooling tower structure. This enables greater efficiency, making it easier to maintain and change parts, if necessary.
A concern with some cooling towers is the loss of water, which makes the process less efficient and runs the risk of harming the environment. While most cooling tower systems evaporate only H₂O into the air, which is harmless, sometimes larger droplets remain in the evacuated vapor, which can carry damaging chemicals to the ecosystem.
A solution to this is to use drift eliminators. Drift refers to those larger droplets that should be reduced, and drift eliminators usually consist of surfaces built into the system that cause the droplets to change direction, therefore losing velocity.
This makes the droplets fall back into the system. Good drift eliminator parts can reduce drift
dramatically, making any drift loss negligible.
Louvers are also a common part used in cooling tower design. There is always a need to reduce water splash-out and increase the control of airflow in a cooling system. Manufacturers include louvers as part of the cooling tower design to accomplish this.
Louvers can be moving or stationary, made from fiberglass or metal, in most cases. Louvers can also incorporate anti-UV material to maximize life span and reduce maintenance requirements.
An essential component of any cooling tower is the distribution assembly used to transport air and water through the system. Since this component usually is subjected to the most friction and wear and tear, the right distribution assembly can make a big difference in increasing the longevity and efficiency of the overall cooling tower setup.
Cooling Tower Drives
You need top-quality drivers to power a cooling tower system. These are the ‘guts’ of any cooling tower.
The drives contain numerous moving parts and are prone to malfunction or break.They are difficult to inspect, disassemble and maintain due, to the complexity of design.
Fills are a crucial component of any cooling tower. The main principle behind cooling towers is to increase surface area contact with air and water, using fills, which enable higher dissipation rates from the extended air-water interface.
There are two main types of fills used: splash and film. Film uses more layers to pass the water over and provides greater surface area, while splash breaks the water into droplets.
For many installations, film fills will be more efficient. Fill design has been advanced a lot in recent years, and quality materials have been shown to result in much greater performance.
The fans used in cooling towers can vary to a certain extent in both design and function, and should match well with the throughput rate and horsepower used for maximum efficiency. Fan systems that are not well calibrated will result in either a throughput bottleneck or wasted power consumption. Fans are often made from FRP or aluminum, and can be axial or centrifugal.
Although they only make up a very small percentage of the overall components of a cooling tower, the quality and types of nozzles used can make a big difference in the successful functioning of the entire system. The nozzles control the amount and dispersal of water, and the cheaper nozzles wear out very quickly.
Cooling towers are among the most revolutionary feats of engineering of the past 100 years. Cooling tower systems are complex functioning, and many of the parts are prone to breakage. This reinforces the importance of purchasing quality parts and maintaining the system correctly.