How to maintain and service cooling towers

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A cooling tower is a device that uses the contact between air and water (directly or indirectly) to cool water. It is a device that uses water as a circulating coolant to absorb heat from a system and release it into the atmosphere, thereby reducing the temperature of the circulating water in the tower and enabling the cooling water to be reused. As the cooling tower industry continues to develop, more and more industries and enterprises are adopting cooling towers, and many companies have entered this industry and are growing within it. Depending on the relative flow of water and air, different types of cooling towers have their own advantages and disadvantages. This is a topic that has been the subject of ongoing academic debate within the cooling tower industry. Such debates have significantly contributed to the technological advancement of cooling towers; by identifying strengths and weaknesses in various approaches, the technology continues to improve, with efforts aimed at saving energy, reducing consumption, enhancing efficiency, and lowering costs. The thermal performance of a cooling tower, its noise level, power consumption, and water leakage are key factors in determining the quality of a cooling tower; they are also the aspects that users and designers pay closest attention to when selecting a cooling tower. Of course, its maintenance is also very important. I. Initial maintenance: 1. Remove dirt and clean the cooling tower casing and frame. 2. Removal of dirt and cleaning of the air intake grilles of the cooling tower. 3. Rinse the scale and moss on the surface of the cooling tower fill with clean water. 4. Removal of dirt and cleaning of the cooling tower filter screen. 5. Clean the dirt from the cooling tower’s sprinkler system, adjust its balance, regularly lubricate the rotor and replace its bearings; if the rotor is damaged, replace it. 6. Clean the dirt and residues from the water collection basin, and check whether the cooling tower basin is leaking; address any issues found. 7. Check all fasteners of the cooling tower for looseness, and tighten any loose fasteners. 8. Inspect the motor of the cooling tower, replace the grease inside the motor, lubricate the bearings, and replace the oil seals. Check the condition of the motor bearings; if they are damaged, replace them. During maintenance, ensure that the magnetic gap is even, and use instruments for testing in order to maintain a uniform current during operation, thereby extending the bearing’s service life. 9. Inspect the connectors of the cooling tower, lubricate the bearings, and replace the oil seals. Also check whether the oil level is appropriate; if the bearings are damaged, replace them. 10. Check the cooling tower fan for any accumulation of dirt or scale; if present, remove it carefully to maintain the fan’s balance. 11. Check the tension of the cooling tower belt and adjust the motor belt to the optimal position in order to extend its service life; if the belt is damaged, replace it. 12. Apply rust-proof paint to the motor and connectors of the cooling tower. Check the galvanized parts of the cooling tower for any damage or corrosion; if present, treat them with anti-rust paint and corrosion-resistant materials. 13. Conduct a thorough inspection of the cooling tower’s operation: Check whether the fans rotate clockwise with the airflow directed upward, whether the fans operate smoothly, whether the rotating water distributors function properly or whether the nozzles distribute water evenly, and whether the motor has adequate moisture protection measures in place. II. Monthly maintenance 1. Check the operation of the sprinkler system and adjust it to optimal condition ； 2. Check and tighten the bolts connecting the transmission components to the tower. 3. Inspect the operation of the transmission components, adjust the tension of the belt, and resolve any issues that arise ； 4. Clean impurities and scale from the collection basin ； III. Maintenance Procedures for Cooling Towers (I) Cleaning and Maintenance after the Cooling Tower is Shut Down 1. Sprinkler System ① Check the main water pipes, branch pipes, and nozzles of the cooling tower for any damage or looseness, and repair or secure them as necessary. Thoroughly clean the dirt inside the water distribution pipes and nozzles to ensure smooth flow of water and even distribution of water from the nozzles. ②Thoroughly clean the cooling tower water basin and the outlet filter screen to prevent scale and debris from accumulating and blocking the pipes. After cleaning, the drain valve should be opened to drain all the water from the tray, to prevent it from freezing. ③Check whether the water tray and tower base are leaking; if there are leaks, apply sealant promptly. 2. Cooling system: ① Clean all the heat exchange materials (fillers) in the cooling tower, thoroughly removing scale and dirt from the surface of these materials as well as from between their pores, to ensure that they remain clean. Repair and replacement are carried out when removing and installing the heat exchange material. Be careful to arrange them tightly during loading, leaving no gaps. ②Clean the water barrier and sound-dampening mat to remove dirt. Repair and replace the damaged parts. When stacking the water barriers, they must be placed tightly to prevent water from seeping through. Fill the cooling tower with water and check for leaks (especially at the connections of the tower); if there are leaks, replace the seals. 3. Transmission system: ① Motor: Check whether the motor’s wiring terminals are in good condition, whether the motor rotates properly, ensure that the motor’s wiring box is sealed, lubricate the motor bearings, and repaint the motor housing. In the event of a long-term shutdown, it is recommended that the owner run the motor for at least 3 hours per month to keep the motor coils dry and to lubricate the bearing surfaces. ②Reducer: Check whether the reducer rotates properly; if there are abnormal noises, replace the reducer bearings immediately. ③Belts, pulleys: Adjust the set screws, loosen the belt, and extend its service life. Check the belt for any damage or cracks; if necessary, it is recommended that the owner replace it with a new one. Check the pulley and the levelness of the motor frame; tighten any loose bolts, and replace those that are corroded. ④Fan: Clean the dirt from the surface of the fan blades, check the angle of the blades as well as the gap between the blades and the fan casing, and make adjustments if necessary. 4. Tower appearance: ① Thoroughly clean the wind chamber, tower, and inlet guide vanes to ensure a clean and attractive appearance. ②Retighten the bolts in all areas and replace the rusty ones. ③Check the exterior of the tower for any damage or cracks, and repair them promptly. ④Inspect whether the vertical joints in the tower’s wall panels are sealed properly; apply glue again for repair if necessary. 5. Cooling tower accessories ① Check the automatic water replenishment system – verify whether the float is damaged and functioning properly. Any abnormalities found should be repaired or replaced promptly. ②Re-tighten the bolts of the cooling tower’s metal components, replace the rusty bolts, and repaint the corroded metal parts. ③Check the inlet and outlet pipes, as well as the flanges on the tower for any damage or leaks. Once the cooling tower has been cleaned and maintained, it is recommended that the owner use colored barrier cloth to cover and seal the tower’s air chamber, in order to prevent debris from entering the tower. (II) Inspections and adjustments before starting the cooling tower: ① Remove the cover from the air chamber, adjust the set screws, and fine-tune the tension of the belt. ② Thoroughly check whether the motors and reducers in the cooling tower’s transmission system are operating properly. ③Inspect and clean the dirt from the water basin and filters of the cooling tower; drain water to check the condition of the water basin as well as the airtightness at the base of the tower. Adjust the position of the float so that the water level in the basin meets the required standards. ④Adjust the blade angle and measure the motor current to bring it within the optimal operating parameters. ⑤Adjust the inlet and outlet valves of the cooling tower to achieve the required water flow rate in the cooling tower. It is required to be in operation for a formal startup. (III) Inspection and monitoring of cooling towers during operation: ① Regularly inspect the cooling towers that are in use, seek feedback from users, and understand their usage conditions. ② Carefully measure technical parameters such as the inlet and outlet water temperatures of the cooling towers as well as the current consumption of the motors. ③Carefully check the operating condition of transmission devices such as motors and reducers. Check the actual operating conditions of the water distribution system. ④If a fault is detected, address it immediately.