Air Pre-Heater Manufacturer in India

What is an Air Preheater?

An air preheater (APH) is a heat exchanger that recovers waste heat from flue gases and uses it to preheat combustion air entering boilers, furnaces, or kilns. This improves combustion efficiency and reduces fuel consumption by 5-15%.

How Air Preheaters Work

1. Hot Flue Gases (250-400°C) exit the boiler/furnace and pass through the APH.

1. Cold Combustion Air (ambient temp) flows in the opposite direction (counter-flow design).
2. Heat Transfer occurs through:
   1. Rotating heat-absorbing elements (regenerative type)
   1. Stationary tubes/plates (recuperative type)
3. Preheated Air (150-300°C) enters the combustion chamber, requiring less fuel to reach ignition temperature.

Types of Air Preheaters

1. Recuperative APH (Tubular)

• Design: Stationary shell-and-tube heat exchanger
• Advantages:
  • No moving parts → low maintenance
  • Handles high dust loads (cement/steel industries)
• Disadvantages:
  • Larger footprint
  • Lower efficiency than regenerative types

2. Regenerative APH (Ljungström/Rotary)

• Design: Rotating matrix absorbs/releases heat
• Advantages:
  • Compact design
  • Higher efficiency (up to 90% heat recovery)
• Disadvantages:
  • Air leakage risk
  • Requires maintenance of rotating parts

3. Plate-Type APH

• Design: Stacked steel plates create alternating gas/air passages
• Best For:
  • Medium-temperature applications
  • Corrosive flue gases (with coated plates)

4. Heat Pipe APH

• Design: Sealed pipes with evaporating/condensing fluid
• Advantages:
  • No cross-contamination between air/flue gas
  • Passive operation (no moving parts)

Key Benefits

 Fuel Savings – 5-15% reduction in fuel costs
 Higher Combustion Efficiency – Preheated air burns fuel more completely
 Lower Emissions – Reduces CO₂, NOx, and SOx
 Improved Boiler Performance – Stabilizes combustion temperatures

Design Considerations

Factor	Importance
Flue Gas Temperature	Determines heat recovery potential
Air Leakage	Critical for rotary designs (seal quality)
Corrosion Resistance	Stainless steel for acidic flue gases
Fouling Potential	Soot/ash buildup reduces efficiency
Pressure Drop	Impacts fan power consumption

Top Applications

• Power Plants – Boiler efficiency improvement
• Cement Kilns – Preheating secondary/tertiary air
• Steel Industry – Blast furnace air heating

Chemical Plants – Process heating optimization