Super Heater Coils

Product Description

Superheater Coils for Boilers

Superheater coils are critical components in steam boilers used to increase the temperature of saturated steam without raising its pressure. They are typically installed in the hottest part of the flue gas path to absorb maximum heat and turn saturated steam into superheated steam.

What Are Superheater Coils?

Superheater coils are high-temperature heat exchangers made of specially designed tubes that carry saturated steam from the boiler drum. These coils are heated by combustion gases to produce superheated steam, which is ideal for driving turbines in power plants or for industrial processes.

Purpose:

• Increases thermal efficiency

• Produces dry, high-energy steam

• Prevents turbine blade erosion (from wet steam)

• Improves cycle efficiency in power generation (Rankine cycle)

Types of Superheaters:

1. Radiant Superheaters:

   • Located directly in the furnace zone

   • Exposed to radiant heat

   • Higher heat flux, risk of overheating

2. Convection Superheaters:

   • Located in the flue gas path

   • Heated by convection

   • Lower heat flux, more stable operation

3. Pendant and Horizontal Superheaters:

• Orientation based on boiler design

• Pendant: hanging vertically

• Horizontal: laid out in rows above the furnace or convective path

Materials Used:

Because they operate at very high temperatures and pressures, superheater coils are made from high-alloy steels:

• T11 / T22 (1.25Cr-0.5Mo / 2.25Cr-1Mo) for medium temps

• TP304 / TP316 (Stainless Steels) for higher corrosion resistance

• Inconel or other high-nickel alloys for extreme cases

 Inspection & Maintenance:

• Visual inspection for bulging or cracks

• Ultrasonic thickness testing

• Temperature monitoring

• Boiler water treatment to prevent scaling

• Steam flow checks to avoid starvation

Applications:

• Thermal power plants

• Industrial boilers (refineries, paper mills, chemical plants)

• Marine boilers

• Heat recovery systems

Key Design Considerations:

• Steam pressure & temperature

• Flue gas temperature

• Steam flow rate

• Material selection

• Tube size & coil geometry