Air Cooled Heat Exchanger Manufacturer in Tunisia

Types of Fin material used in Air Cooled Heat Exchanger?

This is one of the most common and cost-effective types.

Construction: A strip of fin material (the “L”) is wound under tension into a helical groove machined or rolled into the base tube. The fin foot sits securely in the groove.
Common Materials: Aluminum (most common), Copper, Carbon Steel.
Key Characteristics:

Good Contact: Provides good metallurgical contact between the fin and tube, leading to decent heat transfer.
- Fin Density: Allows for a medium to high fin density (7-11 fins per inch / FPI).
- Limitation: The fin foot creates a small gap at the base, which can be a point for corrosion initiation. It also has a slight resistance to heat flow at the base.

Similar to L-fins but with a different fin foot profile.

Construction: The fin strip has a rectangular cross-section (“I” or “G” shape). It is forced into a machined groove in the base tube, causing the tube material to cold-flow around the fin foot, creating a tight mechanical bond.
Common Materials: Aluminum, Copper.
Key Characteristics:
- Excellent Contact: Provides superior mechanical and thermal contact compared to L-fins, with virtually no air gap.
- Robust: Very resistant to fin loosening due to thermal cycling or vibration.
- Application: Often used in high-performance applications where reliability is critical.

This type is monolithic, meaning the fin and tube are a single piece of material.

Construction: The fins are formed by pulling (extruding) the tube material itself through a die, creating fins that are integral to the tube wall.
Common Materials: Copper, Aluminum, and various copper alloys (e.g., Admiralty Brass, CuNi).
Key Characteristics:
- Perfect Thermal Bond: No contact resistance whatsoever, offering the highest heat transfer efficiency per unit length.
- Extremely Durable: Highly resistant to mechanical damage and corrosion at the fin root.
- Limitations: Lower fin height-to-thickness ratio, resulting in lower fin density (typically < 5 FPI). It is also the most expensive option.

Used for applications where a strong, reliable bond is needed between dissimilar metals.

Construction: Fins are welded to the base tube. Common methods include resistance welding (where a small nugget welds the fin foot to the tube) and laser welding.
Common Materials: Any weldable combination, most commonly Carbon Steel fins on Carbon Steel tubes or Stainless Steel fins on Carbon Steel tubes.
Key Characteristics:
- No Galvanic Corrosion: Allows for the use of fin and tube materials that are far apart in the galvanic series (e.g., aluminum fins on carbon steel tubes would cause rapid corrosion, but welded stainless steel fins prevent this).
- Excellent Thermal Contact: The welded joint provides very low thermal resistance.
- High-Temperature Capability: Suitable for very high process temperatures where other fin types would loosen or fail.

This is a different construction style, typically used for the cooler bank (bottom section) of a steam condenser in a power plant.

Construction: Flat, plate-like fins are sandwiched between two parallel tubes and brazed or welded together to form a single block or core.
Common Materials: Typically aluminum fins with aluminum tubes.
Key Characteristics:
- Very High Fin Density: Allows for extremely compact designs with very high surface area density.
- Lightweight: Common in automotive radiators and AC condensers, but also used in large ACHEs for specific services.

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