The Importance of Flushing New Units, General Cleaning, and High Approach Problems in Cooling Systems

1. Why Must New Units Be Flushed Before Operation?

When a new cooling tower or chiller system is installed, there are various contaminants that must be cleaned through the flushing process:

What Is Cleaned During Flushing?

• Construction debris: metal shavings, dust, solder flux, and installation residue

• Lubricants and grease: residues from manufacturing and installation processes

• Early corrosion particles: oxidation on metal surfaces that are not yet fully protected

Risks of Not Flushing for new unit

• Clogging of strainers and nozzles

• Decreased efficiency of heat transfer

• Early corrosion on system components

Our Flushing Process:

1. Pre-flushing with pressurized water

2. Chemical flushing using special alkaline chemicals

3. Final rinsing and passivation for anti-corrosion protection using special chemicals

2. Why is General Cleaning of Cooling Towers & Chillers Necessary?

Problems with Cooling Towers Without Cleaning

• Biofouling: growth of algae and bacteria

• Scaling: accumulation of minerals (CaCO3, MgSiO3)

• Under deposit corrosion: hidden corrosion under scale

• Sludge: sludge deposits in the basin

Problems with Chillers Without Cleaning

• Tube fouling: accumulation of deposits in heat exchanger pipes

• Reduced heat transfer: decreased efficiency

• Increased energy consumption: increased compressor load

General Cleaning Process:

• Mechanical cleaning: brushing and hydrojetting

• Chemical cleaning: acid cleaning and neutralizing treatment

• System inspection: inspection of cleaning results

3. Why is the Approach High?

Approach temperature (the difference between the cooling tower outlet water temperature and the wet bulb temperature) increases due to:

Causes of High Approach

1. Fouling on the filler

   • Decreased heat transfer surface area

   • Suboptimal air flow

2. Clogged nozzles

   • Uneven water distribution

   • Reduced distribution area

3. Dirty drift eliminator

   • Hindered air flow

   • Decreased cooling capacity

4. Unbalanced air flow

   • Inappropriate fan speed

   • Air bypass occurs

4. Benefits of Cleaning the Cooling System

1. Restored thermal efficiency (approach temperature returns to normal)

2. Energy savings (reduced fan and pump load)

3. Prevention of under deposit corrosion

4. Extended equipment life

5. Reduced maintenance costs

5. Under Deposit Corrosion: Silent Killer

What is Under Deposit Corrosion?

A condition where:

• Local corrosion occurs under the deposit/scale layer

• Pipes appear intact because scale covers corrosion holes

• When cleaning is performed, scale is removed and corrosion holes become visible

Mechanism of Occurrence:

1. Deposits create differences in oxygen concentration

2. The area under the deposit becomes anodic

3. Local corrosion occurs progressively

4. When cleaning, scale is removed and holes become visible

Prevention Solutions:

• Routine cleaning to remove deposits

• Proper water treatment

Our Professional Services

We provide:

• Flushing of new units with specialized chemicals

• General cleaning of cooling towers, PHEs, and chillers

• Performance analysis for system optimization

• Integrated water treatment programs

📞 Contact our expert team for a free consultation

Get an efficient and trouble-free cooling system.

“Preventive maintenance is cheaper than emergency repairs”