What does a Cooling Tower do?
Similar to water chillers, Cooling Towers are used in supplying cool water to the machinery or manufacturing process, and recirculating high-temperature water back to the Cooling Tower to decrease its temperature. The main differences between water chillers and cooling towers are the temperature requirements, and operating and maintenance costs. Cooling Towers can be considered if the water temperature requirements are above 30°C, anything below requires water chillers.
Apart from process cooling, Cooling Towers are also mandatory for water-cooled chiller units to cool down its condenser, which may reach high enough temperatures that could end up impacting the performance of the chiller units.
When deciding on the type of Cooling Tower specification or refrigerant tonnage (RT) requirements, the following information is crucial to know:
- Heat rejection from the process or machinery
- Capacity (HP or RT) of the water-cooled chiller
- Inlet and Outlet water temperature + Water flow rate
The operation and maintenance of the cooling tower are also important as they can affect the efficiency and performance of the cooling tower.
One of the major components of a cooling tower is the cooling tower fan set which is driven by an electric fan motor. The function of this fan set is to draw fresh air into the cooling tower through the inlet louver for fresh air to be exchanged with the return warm water, either on a counter-flow basis (mostly for round cooling towers) or cross-flow basis (for square cooling tower) which discharges the hot air upward through the fan stack. Through this process, evaporation will take place that requires water to be added to the cooling tower. Therefore, the pitch angle of the fan blade is equally important as it must be adjusted correctly for the cooling tower to perform at its optimum condition.
If the pitch angle is adjusted too high, it will create more evaporation as well as consume more electricity. Whereas if the pitch angle is adjusted too low, it will not be able to draw enough fresh air for the heat exchange to happen and this will affect the efficiency and performance of the cooling tower in general.
Therefore the pitch angle of the fan set must be adjusted and calibrated by trained Amcon technicians to achieve its efficiency and performance.
Apart from the fan set, the rotating sprinkler head used for the round counter flow cooling tower is equally important. The rotation per minute (rpm) varies from different cooling tower models.
For the return warm water to be equally distributed and flow through the PVC corrugated infill, the rpm of the rotating sprinkler head must follow the rpm set for each model. If the rotational speed is too fast, the water might not be able to equally distribute, and the heat exchange with fresh air through the PVC corrugated infill will not be adequate. If the rotational speed is too slow, it will not have enough water to exchange heat with fresh air through the PVC corrugated infill.
It’s important to ensure that the PVC Corrugated Infill is not clogged because when heat is exchanged for fresh air, the return of warm water will take place through the PVC Corrugated Infill.
If the infill has been clogged, the fan set might not be able to draw fresh air through the clogged infill, therefore, heat exchange between the return warm water and fresh air will not happen and the cooling tower will not be able to remove heat effectively from the returning warm water, in turn, failing to achieve the required temperature.
Since the material of the Corrugated Infill is made by PVC sheet, generally the shelf life is approximately around 5 years, therefore, it is advisable to replace the PVC Corrugated Infill every 5 years, even for a well-maintained cooling tower.
In order to maintain a clean PVC corrugated infill, it’s important to make sure that the water quality for the system is well maintained. This can be done through an effective water treatment program either weekly or monthly depending on the water quality.
Amcon is able to provide all stock and spare parts for most brands used in Malaysia. Please drop us a message for any inquiries.
