The following are special precautions for maintenance of different common types of cooling tower fillers:

1. PVC (polyvinyl chloride) fillers

Chemical stability:

Although PVC fillers have good corrosion resistance, they are relatively poor in tolerance to certain organic solvents and strong oxidizing substances. When performing chemical cleaning, special attention should be paid to the selected descaling agents, bactericides and other chemical agents that do not contain ingredients that react with PVC. For example, avoid using agents containing strong organic solvents such as benzene and ketones, so as not to cause the filler material to soften, deform or even dissolve, thereby destroying its structural integrity. Cooling towers used in environments where such special substances may be produced, such as chemical production, must strictly control the composition of foreign chemical substances introduced into the circulating water.

Temperature sensitivity:

PVC has limited thermal stability. It is prone to aging, hardening and brittleness when it is in a high temperature environment for a long time (generally more than 60°C for continuous action), which in turn affects its mechanical properties and heat dissipation performance. Therefore, during maintenance, it is necessary to pay attention to the operating water temperature of the cooling tower. If the water temperature is found to be abnormally high for a long time, the cause should be promptly checked (such as whether the cooling water volume is insufficient, whether the heat exchange equipment is faulty, etc.) to prevent the PVC filler from being damaged by high temperature. At the same time, during the high temperature period in summer or when the heat load of the cooling tower is large, the cooling water volume can be appropriately increased to control the water temperature and protect the filler.

Prevention of physical damage:

PVC filler is relatively brittle. When performing maintenance operations such as appearance inspection and cleaning, be extremely careful when using tools. For example, when flushing with a high-pressure water gun, control the water pressure and flushing angle to avoid filler rupture due to excessive impact force; when manually cleaning debris, do not use sharp tools to strongly scrape the filler surface to prevent scratches, breakage, etc., which will affect its normal use and heat dissipation effect.

2. PP (polypropylene) filler

Antioxidant maintenance:

PP filler is easily affected by oxidation during use, especially in the presence of light, high temperature and oxidizing substances. It is more likely to undergo oxidation reactions, causing the filler surface to turn yellow and become brittle, thereby reducing performance. Therefore, during the operation of the cooling tower, for situations where it is exposed outdoors or in direct sunlight, it is possible to consider taking certain sun protection measures inside the cooling tower or on the surface of the filler, such as applying protective paint with anti-ultraviolet function; at the same time, adding antioxidants to the circulating water (products that meet relevant health and environmental protection standards and are compatible with PP materials must be selected) to enhance the filler's antioxidant capacity and delay its aging process.

Key points of welding repair:

When the PP filler is partially damaged and needs to be repaired by welding, due to the welding characteristics of the PP material, it is necessary to ensure that the welding equipment temperature, welding speed and selection of welding rods meet the requirements. The welding temperature is generally controlled between 200℃ - 280℃. If the temperature is too low, it is difficult to achieve good welding. If the temperature is too high, it is easy to cause local overheating and deformation of the filler. The welding speed should be uniform during welding, so that the welding rod is fully melted and fused with the filler matrix to ensure the strength and sealing of the weld. After the repair, the flatness of the welding part should be checked to avoid affecting the normal flow of water and air.

Prevent deformation: PP filler is prone to deformation when it is squeezed by a large external force, subjected to uneven force for a long time, or when the water temperature changes drastically. During installation, it is necessary to ensure that the filler is installed flat and firmly to avoid uneven force such as partial suspension; in daily maintenance, attention should be paid to whether the filler has signs of deformation caused by water flow impact, abnormal air flow, etc. If slight deformation is found, the filler can be restored to its normal state by appropriately adjusting the support structure and repairing the water distribution system to prevent the deformation from further aggravating and affecting the heat dissipation performance.

3. FRP filler

Resin matrix maintenance: FRP filler is made of resin as the matrix and glass fiber as the reinforcing material. The performance of the resin matrix has a great influence on the overall filler. To prevent the resin matrix from being chemically eroded, for example, avoid long-term contact with strong acid and alkali substances (different types of resins have different tolerance ranges, but generally speaking, strong acids and alkalis will cause damage to them). In the use environment where such substances exist, it is necessary to strengthen the monitoring and regulation of the circulating water quality, and take neutralization and isolation measures when necessary. At the same time, regularly check whether the resin surface has cracks, peeling and other phenomena. If problems are found, promptly use the same type of resin material to repair it to prevent moisture from penetrating and further damaging the internal structure of the filler.

Fiberglass protection:

The exposed fiberglass is prone to cause a series of problems, such as being corroded by corrosive components in the air and water, resulting in a decrease in the strength of the filler, and may also injure the operator. During the maintenance process, once the fiberglass is exposed, the exposed part should be carefully cut off with tools, and then covered and repaired with resin and other materials. In addition, when cleaning, inspecting and other operations, try to avoid external force pulling to cause the fiberglass to fall out of the filler to maintain its structural integrity.

Fire performance concerns:

Some fiberglass fillers will add some flame retardants during the production process to meet fire protection requirements, but with the increase of use time and the influence of environmental factors, its fire resistance may decline. In some places with high requirements for fire prevention (such as cooling towers near flammable and explosive areas), the fire resistance performance indicators of the filler (such as oxygen index, etc.) should be tested regularly. If it does not meet the requirements, measures such as re-applying fire-retardant coatings can be considered to enhance its fire resistance and ensure the safety of the cooling tower and the surrounding environment.

4. Ceramic filler

Fragility protection:

Ceramic fillers are hard but brittle and are easily broken by external forces such as collisions and impacts. Therefore, extreme caution should be taken during maintenance operations to avoid using hard objects to knock or collide with the filler. For example, when cleaning up debris and checking the appearance, tools should be used with care, and people entering the cooling tower should also pay attention to their own behavior to prevent accidental kicking or touching the filler and causing damage. In daily operation, it is also necessary to prevent the ceramic filler from being broken due to abnormal conditions such as turbulent water flow and air wave impact in the cooling tower. The internal flow field can be maintained stable by optimizing the water distribution system and adjusting the operation of the fan.

Difficulty of cleaning scale:

The ceramic surface is relatively rough and is more likely to absorb impurities in the water. It is difficult to clean after scaling. When cleaning scale, in addition to soaking and circulating cleaning with appropriate chemical descaling agents, some physical grinding methods may be required, but the grinding intensity and range should be controlled to avoid damaging the structure of the ceramic filler. At the same time, in order to reduce scaling, more attention should be paid to water quality management, and the hardness, pH and other indicators of circulating water should be strictly controlled to reduce the risk of scaling from the source.

Corrosion resistance inspection:

Although ceramics themselves have a certain degree of corrosion resistance, different types of ceramics have different tolerances to different chemical substances. In a complex chemical environment (such as industrial wastewater recycling scenarios containing a variety of acids, alkalis and salts), the corrosion of ceramic fillers should be checked regularly to observe whether there are erosion marks, pitting and other phenomena on the surface. If there are signs of corrosion, the degree of impact on the performance of the filler should be evaluated. If necessary, the damaged filler part should be replaced in time to ensure the normal operation of the cooling tower.

Due to their own material and structural characteristics, different types of cooling tower fillers have their own special matters that need to be focused on during maintenance. Only by doing these maintenance work in a targeted manner can the performance and service life of the filler be better guaranteed, thereby ensuring the efficient and stable operation of the cooling tower.