Cooling towers are all around us — from office buildings to large manufacturing plants — and they serve an important role in the continuous operations of various industries and the manufacturing sector. In this article, we’ll talk about what cooling towers are, what types are available for companies, and more. Read on!
What is a Cooling Tower?
A cooling tower is a device that removes heat using water, transferring waste heat into the atmosphere. An industrial cooling tower removes water by evaporating a small portion of water that is recirculated through the unit. When warm water and cool air mix, the reaction releases latent heat of vaporization. This causes the water to cool.
Cooling towers are mainly used for heating, ventilation, and air conditioning (HVAC) and industrial purposes. Many companies use them because they’re efficient and cost-effective. You can find them in large office buildings, schools, and hospitals.
Industrial cooling towers are larger than HVAC systems. They remove heat absorbed in circulating cooling water systems in power plants, petrochemical plants, food processing plants, petroleum refineries, natural gas processing plants and other industrial facilities.
Types of Cooling Towers
Cooling tower systems come in many forms. They may be categorized by the draft type they have or the direction of airflow inside them:
Natural Draft Cooling Systems
Natural draft cooling systems are used in large power plants and industries with infinite cooling water flow. The tower removes waste heat by raising hot air and releasing it into the atmosphere. These towers are often tall and have hyperbolic shapes to promote proper airflow.
Mechanical Draft Cooling Systems
Mechanical draft cooling towers force air through the structure using a fan that circulates air through the tower. Common fans like propeller and centrifugal fans are used in such towers. These are more effective than natural draft cooling systems, but they consume greater power and cost more to operate.
Crossflow Cooling Tower Systems
Crossflow cooling towers are designed to allow air to flow horizontally through the fill and the structure into an open plenum. Hot water flows down from the distribution basins. Fans and motor drives in these tower systems require weather-proofing to prevent moisture, which can cause freezing — this makes the tower less efficient.
Counterflow Cooling Towers
Counterflow cooling towers move air upwards while the countercurrent with hot water falls down to cool the air. This enables maximum performance while minimizing pump head requirements. On top of that, counterflow cooling towers are less likely to freeze in cold weather, saving energy in the long run.
Induced Draft Cooling Towers
Induced draft cooling towers are mounted with a fan at the top. This allows hot air out and pulls air throughout. The exiting air velocities reduce the chances of re-circulation. To prevent water droplets from getting stuck in leaving stream air, the towers have drift eliminators. Induced draft towers use 30% to 75% less energy compared to forced draft systems.
Forced Draft Cooling Towers
Forced draft cooling towers are just like induced draft towers. The main difference is that the fan moving the air is at the base of the cooling tower. This allows air to blow through from the bottom. Fewer companies use forced draft towers because of water distribution problems. They also use high-horsepower fans, and there’s a possibility of re-circulation.
Why Cooling Towers are Important
As the world’s population grows, manufactured products become more in demand. As a result, the industrial sector needs to produce more products, generating more manufacturing heat. The machines and processes of these industries generate tremendous heat that must be continuously cooled. Without cooling towers, the manufacturing machines can’t operate efficiently.