Cooling towers are important components of a building or factory. They ensure a comfortable environment for occupants in your building and keep your processes running.
That’s why it’s important to invest in high-quality cooling tower parts, regardless of whether you’re installing them for the first time or if you are replacing failing parts.
In this post, we will briefly explain the parts found in a cooling tower, what they do, and when they usually need replacing. Having this knowledge will help you avoid costly repairs.
But before we dive into them, it’s important to understand why preventative maintenance is needed in the first place.
Preventative Maintenance: Why it matters?
Cooling towers will save energy when they are well-maintained, and operating at their best efficiency. On the other hand, badly maintained cooling towers with dirty infills or drives not in optimal condition will induce more operational costs.
The reason for preventative maintenance is to help prevent breakdowns and unnecessary costs that rise from your cooling towers running sub optimally.
Preventative maintenance operations typically include:
Recording daily maintenance logs.
Preventative maintenance tasks should be carried out daily, weekly, monthly, and annually.
Having technicians record a daily cooling tower log will help to build out a history of your tower operation conditions, its efficiency, and the status of each part. Daily visual inspections are done to make sure fundamental operations like water flow rate and levels are appropriate.
We recommend checking belts, pulleys, and the water quality monthly. Checks on wear & tear, alignment, and mineral built-up should be scheduled regularly.
Motor bearings and other parts of your cooling tower should be inspected and cleaned at least once a year.
Keeping cooling tower fills clean.
One of the most important parts of a cooling tower is the cooling tower fills – commonly, a plastic sheet used to increase the surface area of the tower to allow more contact between air and water, facilitating the transfer of heat from water to the air.
Over time, tower fills can get clogged with dirt, mud, minerals, and debris. This reduces the cooling efficiency of your cooling tower.
We recommend cleaning your tower fills at least once every quarter.
Cooling tower water management.
Aside from parts maintenance, maintaining your cooling tower system water condition is equally as important, if not more crucial to keep the cooling process efficient.
Left unattended, water can bring about microbiological growth like algae and fungi, scaling issues, and equipment corrosion. This is why ongoing water treatment is mandatory for every cooling tower.
Water treatment for cooling towers includes processes like removing scale deposits, chemically treating water, filtration, and routine water quality tests.
Cooling Tower Parts: How do they work?
A cooling tower is equipped with many parts, consisting of fans, motors, pulley or gears, fills, and more, which all help circulate air throughout the cooling tower to cool the water.
Here’s a closer look at some of the most important cooling tower parts:
Fans and Fan Cylinders.
Fans and fan cylinders are parts of a cooling tower responsible for creating airflow. Fans are the most effective and reliable way to create airflow. They distribute air through the fill media so it interacts with water.
Fans can last for an average of 10 years before requiring a replacement. However, periodic checks should be carried out, looking out for any dings or cracks.
Fan cylinders, or commonly known as cooling tower fan ducts, are a critical component for protecting the fan blades, minimizing vibration and found, and facilitating optimal fan performance. Fan cylinders are typically fabricated of fiberglass composite material.
Fan cylinders can last throughout the lifespan of the cooling tower, even up to 20 years, unless it is caused by accidental damage, such as an extreme vibration due to mechanical failure causing the fan blade to hit the fan cylinders.
Motors.
Fans can’t operate without the help of an electric motor. A cooling tower motor shall be designed to withstand exposure to hot, moist cooling tower conditions.For cooling tower applications, TEFC (totally-enclosed, fan cooled) motors are most suitable.
A TEFC motor is ideal as it is protected from water and debris, reducing maintenance requirements. The TEFC motor, with its internal fan, does not rely on cooling tower airflow for cooling. Even at slow fan speeds, the motor can continue to cool itself, which helps to extend its service life and increase its reliability.
A drain plug shall be located at the bottom of the motor, depending on the mounting configuration, to allow water to be drained.
Cooling tower motors shall be inspected for abnormal noise and vibration every month. Most cooling tower motors below 100-horsepower include sealed bearings that require no greasing.
Gearbox, pulley systems, motor, and drives.
There are three main types of drive systems: direct drive, belt & pulley drive, and gear driven systems. A direct driven system only consists of a fan and a motor directly driving the fan.
However, most cooling towers cannot have its motor directly connected to the fan – that would cause the fans to turn too fast. Therefore, a speed reduction system is needed between the fan and the motor to reduce, control and maintain the speed of the fans.
Gearbox, pulley systems, motor, and drives are key components that control the speed of fan blades in the cooling tower to provide sufficient airflow through the cooling tower.
Belt & pulley reduction driven systems consist of pulleys of two different sizes and belts wrapped around the pulleys. When the belt starts to spin the pulleys into motion, the mechanism begins to move. The different pulley diameters produce a reduction ratio of input to output speed.
As for gear drives, the motor and fan are connected to a gearbox. The gears in the gearbox mesh together to reduce the motor speed to the optimum fan speed determined by the manufacturer.
When purchasing a pulley set or gearbox from your cooling tower parts supplier, make sure the size and ratio fit the specifications of your cooling tower. Purchasing a belt & pulley or gearbox system with the incorrect speed reduction ratio will result in under or over supply of airflow.
It’s recommended to inspect the drive mechanism monthly, to spot any signs of corrosion or wear and tear. Belts can loosen and require regular tightening. Do expect a full set of belt replacement every 6-12 months, depending on operating hours. As for gear systems, they require gear oil refill every now and then.
Fills & Drift Eliminators.
Cooling tower fills, or known as infills, are used in cooling towers to maximize heat transfer. The fill media is designed with a large surface area that exposes large volumes of warm water to cool air for heat transfer to happen.
There are two main types of fill media:
Splash fill
Film fill
Splash fill uses layers of bars and slats to break hot water splashing it, into tiny droplets. These water droplets interact with cool air for a longer time and thus the temperature in the water drops.
Film fill, on the other hand, is the more popular type of fill, made up of corrugated sheets. They can be combined and stacked in a cooling tower. Water then travels across them and gets cooled in the process.
In all cooling towers, there is an amount of evaporative water loss to the environment. Drift eliminators are designed to minimize this. Drift eliminators prevent the water droplets from escaping the cooling tower that are caught in the air stream.
The commonly used fills and drift eliminators in cooling towers are made of PVC, CPVC or PP – chosen according to the temperature of the cooling tower water.
Cooling tower infills and drift emulators can last anywhere from 5 to 8 years before requiring a replacement. Signs to look for are cracks and brittleness.
Spring Isolators.
Spring isolators reduce the transmission of vibration, shock, and noise rumbles produced by process equipment like a cooling tower within a building structure. They also help shield the cooling tower from wear and tear caused by constant vibrations.
A thing to note is that there are many types of isolators and multiple deflection ratings. Most isolators use springs that are set to a specific tension.
Vibration Switch.
A vibration switch is used to detect when there is excessive vibration by an electric motor or engine, and either trigger an alarm or shut down the equipment.
The vibration switch we offer at Threcell is designed to shut down machinery, to ensure your cooling tower is protected from harmful shock and vibration. The sensitivity level can be adjusted accordingly to your requirements based on the application.
Need cooling tower replacement parts?
It’s normal for parts within a cooling tower to break down over time. The good news is that most of them can be replaced or serviced.
Remember that preventative maintenance will help you avoid downtime, especially when you replace parts that are already showing signs of failing before they fail.
At Threcell, we offer an extensive selection of cooling tower spare parts to keep your cooling towers running. Give us a call at +603-32911881 or contact us to find a cooling tower spare part or request a service maintenance check.