Complete Guide to Cooling Tower Maintenance: Improve Efficiency & Extend Service Life

Cooling towers are the heart of many industrial and commercial cooling systems. This investment will provide maximum returns if properly maintained. Proactive maintenance not only prevents costly damage, but also saves up to 30% in energy and doubles the cooling tower's lifetime.

Here are common cooling tower problems and comprehensive solutions to address them.

Problem 1: Scaling (Scale)

• What causes it? Hard mineral deposits (such as calcium carbonate) from evaporating water. Occurs when the LSI (Langelier Index) is positive and the concentration cycle (COC) is too high.

• Impact: Inhibits water flow and heat transfer, reduces efficiency, increases chiller workload, and wastes energy.

• Solution:

  • Automatic COC Control: Use an Automatic Blowdown system connected to a TDS sensor to precisely remove excess minerals.

  • Chemical Treatment (Bowenco 112): Continuously inject scale inhibitors and dispersants using a Chemical Dosing System. These chemicals bind minerals and prevent them from adhering.

  • Make-Up Water Softening: Use a Water Softener to remove hardness-causing ions (Calcium & Magnesium) from make-up water before it enters the system.

Problem 2: Corrosion (Corrosion)

• What causes it? Chemical/electrochemical reactions that erode metal (pipes, basins, structures). Triggered by low pH, dissolved oxygen, and suspended solids. A negative LSI indicates that the water is corrosive.

• Impact: Pipe leaks, structural damage, short system life, high repair costs.

• Solution:

  • Strict pH Control: Maintain pH within the optimal range (usually 7.5 - 9.0) to form a natural protective layer.

  • Pay attention to Cl and Fe levels: these parameters can also cause corrosion if they exceed the limits. Pay attention to the parameters of the water source.

  • Corrosion Inhibitor Injection: Use chemicals such as Bowenco 112AC anti-corrosion, which forms a protective film on metal surfaces.

  • Coating: Apply epoxy or galvanised coatings to vulnerable parts, such as cold water basins.

Problem 3: Biofouling (Moss, Algae, Bacteria, & Legionella)

• What causes it? Microorganism growth in warm and humid environments. The resulting biofilm (slime) becomes a breeding ground for harmful bacteria such as Legionella.

• Impact: Clogs nozzles and fills, reduces efficiency, and has the potential to cause serious Legionnaires' disease outbreaks.

• Solution:

  • Routine Biocide Programme: Apply two types of biocide:

    • Oxidising Biocide (Bowenco 116MO): Kills microbes quickly.

    • Non-Oxidising Biocide (Bowenco 116MN): Eliminates resistant microbes and disrupts their metabolism. Both are used alternately to prevent resistance.

  • Mechanical Cleaning: Perform periodic water drainage and physical cleaning to remove biofilm and sludge.

Problem 4: Fouling (Sludge, Mud, & Dust)

• What causes it? Accumulation of suspended solids (TSS) such as sand, dust, and biological debris.

• Impact: Clogs the system, becomes a breeding ground for bacteria, accelerates under-deposit corrosion.

• Solution:

  • Side Stream Filter Installation: A filter system that continuously filters 5-10% of the circulating water is very effective at removing TSS.

  • Periodic Basin Cleaning: Schedule regular cleaning of the cold water basin to prevent sludge accumulation.

  • Use of Dispersants: Dispersant chemicals help keep particles suspended in water so they are easily removed during blowdown.

Problem 5: Drift (Water lost to the wind)

• What causes it? Water droplets are carried away by airflow from the cooling tower.

• Impact: Water waste, spread of chemical treatment into the environment, and potential spread of Legionella.

• Solution:

  • Installation of an Efficient Drift Eliminator: This component is designed to capture water droplets before they exit the cooling tower. Ensure that the drift eliminator is in good condition and meets standards (usually drift rate < 0.002%).

Prevention Action Plan: 6 Mandatory Steps for a Longer Lifetime

1. Daily/Weekly Routine Inspection & Monitoring:

   • Check water levels, leaks, unusual water colours, and abnormal noises.

   • Record key parameters: Temperature, Flow, Pressure.

2. Consistent Water Testing & Analysis (Weekly/Monthly):

   • Test water parameters: pH, TDS, Conductivity, Hardness, Alkalinity.

   • Calculate COC, LSI, and RSI to guide the chemical treatment programme.

   • Lab analysis for more detailed parameters.

3. Measured & Automated Chemical Treatment Programme:

   • Use an automated Chemical Dosing System to ensure the dosage of scale inhibitors, corrosion inhibitors, and biocides is always accurate.

   • Regularly audit and evaluate the chemical programme with water treatment experts.

4. Periodic Cleaning & Rinsing (Semi-Annual/Annual):

   • Schedule thorough cleaning (mechanical cleaning) every few months or once a year.

   • Clean the fill packing, nozzles, spray, drift eliminator, and basin of all scale and deposits.

5. Mechanical Component Maintenance:

• Inspect and maintain motors, fans, gearboxes, and bearings. Ensure that the belt drive settings are correct.

• Check nozzles for blockages to ensure even water distribution.

Proper Shutdown & Lay-Up:

• When the cooling tower is not in use for a long period of time (backup use only), perform the proper shutdown procedure to prevent corrosion.

Don't let small problems ruin your investment.

With a comprehensive and proactive maintenance programme, your cooling tower will operate efficiently, safely, and have a long service life.

Consult your cooling tower maintenance needs with our team of experts. We provide solutions ranging from water analysis, chemical treatment programmes, professional cleaning, to the supply of supporting equipment. Contact us now to schedule a free inspection in the Greater Jakarta area.