en flag
en flag

Strategies for Maintaining Cooling Towers Sea Side Combating Corrosion and Damage Caused by Sea Air.

Cooling towers located near the coast or sea face a unique challenge: salt carried by sea spray. Once dissolved in cooling tower water, this salt becomes a major contributor to corrosion, scaling, and other operational issues.

To keep your cooling system durable, efficient, and free from costly damage, specific maintenance is essential.

Main Threats: Sea Salt and Increased TDS

Salt-rich air from the sea is carried by the wind, enters through the air inlet, and sticks to the cooling tower's filler (cooling media). This salt then dissolves and drips into the water basin, drastically increasing the Total Dissolved Solids (TDS) level of the cooling tower water.

High TDS, especially from salt (chloride), has two fatal effects:

  1. Corrosion: Salt accelerates the rusting (corrosion) process on metal components (pipes, basins, heat exchangers).

  2. Scale: Salt, along with other minerals, forms scale that reduces heat transfer efficiency.

Special Maintenance Solutions for Cooling Towers near the sea

To overcome this problem, maintenance must focus on three main pillars: chemical protection, automatic control, and routine monitoring.

1. Best Chemical Protection (Chemical Treatment)

In a high-salt environment, chemical treatment can no longer be carried out as usual. You need a specially designed formulation:

  • Use Special Anti-Corrosion (Example: Chemical Bowen Co Anti-Corrosion) Use corrosion inhibitor chemicals at the optimal dosage. These products work by forming a protective film on metal surfaces, preventing chloride ions (salt) from attacking iron or steel materials.

2. Salt Concentration Control (Blowdown)

As salt continuously enters the system, partial water discharge (blowdown) must be performed more frequently.

  • Application of Automatic Blowdown Based on Sensors (Example: Hyrotech Automatic Blowdown) It is important to switch from manual or time-based blowdown to an automatic system controlled by sensors. These sensors continuously measure the TDS or conductivity of the water.

  • Mechanism of Action: Once the sensor detects that the TDS (salt content) has exceeded the set safety limit (due to seawater ingress), the system will automatically discharge the salt-contaminated water and replace it with new, cleaner source water. Thus, TDS is always kept low, minimising the risk of corrosion.

3. Maintain Cleanliness to Prevent Hidden Corrosion

Dirt, dust, and algae that accumulate in the cooling tower can exacerbate corrosion:

  • Prevention of Under-Deposit Corrosion Ensure that the water basin and filler are cleaned regularly. If dirt is allowed to settle, salt will be hidden underneath it. This condition triggers a highly destructive type of corrosion called Under-Deposit Corrosion.

  • Filtration: Consider installing a side-stream filtration system to continuously clean the water of suspended particles that could become deposits.

4. Consistent, Multi-Parameter Water Monitoring

Monitoring is key to responding to salt threats in real time:

  • Routine Water Checks: Perform regular water checks (pH, TDS, Alkalinity, Chloride, Hardness, etc.) to verify the effectiveness of chemical treatment and blowdown.

  • Use an Advanced Multiparameter Analyser: For large facilities, investing in a multiparameter analyser system is highly recommended. These devices can measure several important parameters simultaneously and can be connected to your control system (e.g. via Modbus RS 485 protocol). This allows operators to monitor and adjust chemical dosing or blowdown remotely.

5. Source Water Quality (Make-up Water)

  • Although the focus is on sea salt, the quality of the source water you use for make-up water is very important:

  • By combining strong chemical protection, responsive automatic blowdown, and intelligent monitoring, you can keep your coastal cooling tower efficient and long-lasting, minimising maintenance costs and the risk of failure.

    • Poor Source Water Accelerates Problems: If your source water already has high TDS and hardness, it will add to the load on the system, making blowdown more frequent and costly.

    • Pre-treatment: If possible, ensure that make-up water is of good quality, perhaps with simple pre-treatment such as softening if hardness is high, to ensure the cooling tower only has to deal with incoming sea salt. Blowdown becomes more frequent and expensive.