The cooling tower is nothing but a device used to reduce the heat and increase production efficiency. In simple words, it is used to cool industrial hot water. Its size ranges from tiny to massive towers based on the requirement.
A cooling tower’s main function is to remove heat from water by evaporating a little amount of it. The mixture of warm and cooler water leads to latent heat evaporation causing the water to cool. A commercial cooling tower has an average life expectancy of 15-20 years.
Several industries use a cooling tower, such as chemical manufacturing plants, primary metals processing plants, petroleum refineries, rubber products manufacturing plants, tobacco manufacturing plants, glass manufacturing plants, and textile manufacturing plants.
12 questions about the cooling towers
The cooling tower provides high cooling efficiency, needs less maintenance, consists of reliability and sustainability, and can be operated for a longer duration. Now, let us have a look at a few questions that will help you get clear with the idea behind cooling towers.
1. What is a cooling tower?
A cooling tower is nothing but a heat exchanger. It extracts waste heat to the atmosphere by cooling the water stream to a lower temperature. Water begins to cool when it comes into contact with air. In this way, the same amount of water is evaporated and thereby cool down the hot water.
2. What are the different types of cooling towers?
There are two types of cooling towers:
- Crossflow cooling tower
- Counterflow cooling tower
3. What is an Evaporative cooling tower?
Cooling is provided via an evaporative cooling tower based on a design wet-bulb temperature. This cooling tower can cool water to 85 degrees Fahrenheit. It is the most economical option for cooling a large amount of water.
4. What is entering wet-bulb temperature (EWBT)?
EWBT is nothing but a device that measures the level of humidity in the air entering the cooling tower. The higher the temperature of the wet bulb, the more moisture exists in the air. The cooling tower needs to be larger with a high wet-bulb temperature compared to a lower wet-bulb temperature.
5. What is the difference between ‘counterflow’ and ‘cross flow’ cooling towers?
In a counterflow cooling tower, air travels vertically upwards through the fill and makes intimate contact with water. Hence, both air and water are in opposite directions. In a crossflow tower, air passes through the fill horizontally, crossing the downwards water flow.
6. Why choose the FRP cooling tower?
FRP (fibreglass reinforced polyester) is mixed with a gel coating that protects the cooling tower from direct UV rays. Additionally, it also provides a higher resistance to rot and decay to all FRP portions. Hence, FRP cooling tower manufacture is considered in extreme climate conditions.
7. How do Cooling Towers Operate in Cold and Sub-zero Weather?
In cold weather, the cooling tower is operated with a heat load. The operating water flow is directly bypassed to the cold-water basin to prevent icing if the heat load drops too low. The water flow is maintained over the cooling tower.
8. What is the difference between a ‘Force Draft’ and ‘Induced Draft’ cooling tower?
A Force-draft cooling tower imparts an agitation system that forces air into the tower, and fans are positioned on the side of the cooling water. Meanwhile, induced draft tower works by pulling air from the building and fans are located on the top of the cooling tower.
9. How is Water Loss Calculated in Cooling Tower?
There are three types of water loss in the cooling tower: drift, evaporation, and blowdown. Drift loss is while circulating water for the natural draft tower. Evaporation loss is simple as it sounds, water loss due to evaporation. Blowdown loss is during circulating water that lowers the concentration of solids.
10. What is Cooling Tower Drift?
Drift is undesirable loss of water to the environment through tiny, unevaporated droplets in the existing cooling tower stream. These water droplets carry minerals, microorganisms, debris, and chemicals from the circulating water. Hence, it potentially impacts the environment.
11. What is the regulating organization for cooling tower technology, and where can you learn more about the cooling tower industry?
There’s a worldwide industry named Cooling Technology Institute (CTI) authorized on cooling tower technology. In this institute, there are manufactures, owners/operators, and supplies providing facilities for the cooling tower. Moreover, you can get more information on CTI guidelines and specifications on the CTI site.
12. How to clean Air Inlet Louvers of Cooling Tower?
The best method to remove the minerals from the air inlet louvres is to remove the louvre equipment and let them soak in the cold-water basin of the unit. The chemicals present in the water treatment unit will neutralize and dissolve the minerals buildup. The time depends on the severity of the buildup.