Maintaining Heat Exchangers: Cleaning Best Practices

Introduction

Heat exchangers are key players in industrial operations. Whether you’re managing an HVAC system, running a power plant, or maintaining a marine engine, heat exchangers are critical for transferring heat efficiently between fluids without direct contact. But over time, they become less effective due to fouling, scale buildup, and contamination.

Neglecting proper maintenance doesn’t just reduce performance, it can increase energy consumption, disrupt operations, and result in costly repairs or downtime. Regular cleaning is essential to keep your system running smoothly and safely.

At Epoxy Oilserv Nigeria Ltd, we provide industry-grade cleaning chemicals like Epochem 120 Acid Cleaner and Epochem 130 Alkaline Cleaner to help you get the most out of your equipment. In this guide, we’ll walk you through the best practices for maintaining heat exchangers through routine cleaning, smart chemical use, and safety-first techniques.

Why Heat Exchangers Need Regular Maintenance

Heat exchangers often work under extreme conditions, including high pressure, fluctuating temperatures, and exposure to various process fluids. These conditions lead to the accumulation of unwanted materials inside the exchanger.

Common Problems Include:

• Scale formation from hard water (calcium, magnesium, silica deposits)
  
• Oil and grease fouling in petrochemical and food applications
  
• Biological fouling like algae, slime, or bacterial growth in open-loop cooling systems
  
• Corrosion and rust due to chemical imbalances or neglect
  
• Particulate fouling from dust, debris, or poor filtration
  

Without proper cleaning, these issues can result in:

• Decline in heat transfer efficiency
  
• Pressure drops across the exchanger
  
• Increased fuel or power usage
  
• Overheating, component wear, or full system failure
  

Preventive cleaning saves money, increases system uptime, and extends equipment lifespan.

Signs Your Heat Exchanger Needs Cleaning

Not every issue announces itself loudly—but when performance drops, your heat exchanger may be telling you it’s time for a deep clean.

Watch for These Indicators:

• Reduced thermal output—heating or cooling takes longer than usual
  
• Unusual pressure readings—a spike in pressure drop across the system
  
• Rising operating temperatures despite unchanged inputs
  
• Noisy operation, vibrations, or fluid flow disturbances
  
• Visible scale, slime, or rust when inspecting accessible parts
  

If you see these symptoms, it’s time to plan a cleaning cycle before damage spreads.

Types of Fouling and Their Causes

To clean a heat exchanger effectively, it’s important to understand what kind of fouling you’re dealing with. Different contaminants require different cleaning methods.

Common Types of Fouling:

Left untreated, any one of these fouling types can compromise performance and reduce exchanger life by up to 30–50%.

Cleaning Methods for Heat Exchangers

Now that you know the problem, here’s how to clean it. The method you choose depends on the type of exchanger, the level of fouling, and downtime constraints.

1. Mechanical Cleaning (Manual)

This involves physically removing deposits using brushes, rods, scrapers, or hydro-jetting tools.

Best For:

• Shell and tube heat exchangers
  
• Heavy scaling or large particulate matter
  

Pros:

• Effective on tough, thick deposits
  
• No chemicals needed
  

Cons:

• Labor-intensive
  
• Risk of tube damage if improperly done
  
• Requires equipment shutdown and disassembly

2. Chemical Cleaning (Circulation or Soaking)

A more efficient and less labor-intensive option is chemical cleaning, which uses specially formulated solutions to dissolve fouling without dismantling the unit.

Best For:

• Plate heat exchangers, gasketed units, small shell-and-tube setups
  
• Scaling, corrosion, grease, and organic fouling
  

Common Cleaning Agents:

• Epochem 120 Acid Cleaner – Removes rust, limescale, and calcium
  
• Epochem 130 Alkaline Cleaner – Dissolves grease, oil, and organic residue
  
• Epochem 501 Degreaser – General-purpose cleaning and rust prevention
  

Pros:

• Fast and efficient
  
• Less labor-intensive
  
• Penetrates complex passages and narrow tubes
  

Cons:

• Requires chemical handling knowledge
  
• May need neutralizing or rinsing agents
  
• Must follow SDS guidelines strictly

3. CIP (Clean-In-Place) Systems

For food, pharma, and automated HVAC systems, Clean-In-Place setups allow for closed-loop chemical cleaning with minimal intervention.

• Connect chemical reservoirs to the exchanger
  
• Circulate cleaning agents for a set time
  
• Rinse and flush automatically
  

Pros:

• No disassembly
  
• Reduced labor and safer for operators
  
• Ideal for frequent cleaning cycles
  

Cons:

• Requires upfront investment in equipment
  
• May not handle extreme fouling

Featured Cleaning Solutions from Epoxy Oilserv

Epochem 120 Acid Cleaner

• Formulated to remove scale, rust, and calcium buildup
  
• Ideal for cooling towers, condensers, and shell-and-tube exchangers
  
• Non-fuming and effective on iron, copper, and stainless steel
  

Epochem 130 Alkaline Cleaner

• Targets oil, grease, sludge, and biofilms
  
• Safe on metals, plastics, and rubber gaskets
  
• Often used in plate-type and HVAC heat exchangers
  

Epochem 501 Antirust Degreaser

• Dual action: cleans and prevents corrosion
  
• Excellent for prep cleaning before shutdowns or repairs
  
• Fully biodegradable and non-toxic
  

All Epochem products are available in multiple volumes and backed by detailed SDS documentation for safe industrial use.

Heat Exchanger Cleaning: Step-by-Step Procedure

Here’s a simplified cleaning workflow using chemical methods:

1. Shut down and isolate the heat exchanger
   
2. Drain the system completely and inspect access points
   
3. Choose a cleaning agent based on fouling type (acidic for scale, alkaline for grease)
   
4. Circulate or soak with the chemical (typically 30–60 minutes)
   
5. Rinse thoroughly with clean water or neutralizer
   
6. Inspect tubes or plates for remaining deposits
   
7. Restart the system and monitor performance metrics
   

For systems with CIP access, the entire process can be automated and completed within a few hours.

Safety Tips and Environmental Practices

• Always consult the SDS before handling cleaning chemicals
  
• Use appropriate PPE: gloves, face shield, apron, and ventilation
  
• Avoid mixing different cleaners (e.g., acid + bleach = toxic gas)
  
• Neutralize acidic waste before disposal
  
• Comply with NAFDAC and NESREA regulations on chemical discharge and waste management

How Often Should You Clean?

Cleaning frequency depends on several factors:

• Usage intensity and operating hours
  
• Water quality and treatment systems
  
• Type of fluids and contaminants
  

General Rule:

• Inspect every 3–6 months
  
• Clean annually or as soon as efficiency drops by more than 10%

Frequently Asked Questions (FAQs)

Can I clean a heat exchanger without shutting it down?

Only if your system supports CIP (Clean-In-Place). Otherwise, shutdown is required.

How do I know whether to use acid or alkaline cleaner?

Use acid cleaners for mineral scale and alkaline for oils, organics, or biological fouling.

Will chemicals damage gaskets or seals?

No, if you use non-corrosive, pH-balanced cleaners like Epochem 120 and 130.

What signs indicate it’s time to clean?

Increased pressure drop, reduced heat transfer, or noisy operation.

Can I reuse cleaning chemicals?

Only in controlled conditions. Otherwise, dispose of safely after use.

Conclusion 

Heat exchangers are key players in your operation, don’t let performance drop due to neglect. With the right cleaning schedule, safe chemical agents, and trained staff, you can boost energy efficiency, reduce maintenance costs, and extend equipment life.

For industrial-grade cleaning solutions tailored to Nigerian industries, trust Epochem chemical products—available exclusively at Epoxy Oilserv Nigeria Ltd.