ASTM A312 ASME SA312 Stainless Steel Gombined Metal Extruded Fin Tube For Heat Exchanger
Composite metal extruded finned tubes are bimetallic heat exchanger components that combine two dissimilar metals by an extrusion process. Typically, this process involves a base tube (such as carbon steel or stainless steel) and fins made of a more thermally conductive or corrosion-resistant metal (such as aluminum) that are bonded during the manufacturing process.
The aluminum fin material is first applied to the outside of the base tube and then extruded through a die to form the fins directly from the outer surface of the base tube.
This type of fin can increase cost-effectiveness and optimize material utilization, using cheaper base materials with high-performance fins
Outstanding advantages of aluminum fins
(1) High thermal conductivity
Excellent thermal conductivity: The thermal conductivity of aluminum (about 237 W/m·K) is much higher than that of steel (about 50 W/m·K), which can quickly transfer heat from the base tube to the fin surface, significantly improving the overall heat exchange efficiency.
Uniform heat dissipation: The uniform thermal conductivity of aluminum can reduce local hot spots and prevent deformation of the base tube due to excessive temperature gradient.
(2) Lightweight design
Low density: The density of aluminum (2.7 g/cm³) is only 1/3 of that of steel, which is particularly suitable for weight-sensitive applications (such as air coolers and vehicle-mounted heat exchange systems), reducing structural support costs.
(3) Corrosion resistance
Natural oxidation protection: A dense oxide film (Al₂O₃) is easily formed on the surface of aluminum, which resists corrosion from the atmosphere, water vapor and weak acid environments, extending service life.
Salt spray resistance: It performs better than ordinary carbon steel in marine or coastal environments and is suitable for condensers and seawater desalination equipment.
(4) Economical
Controllable costs: The price of aluminum is lower than that of copper and stainless steel, and the processing energy consumption is low, with obvious comprehensive cost advantages.
Low maintenance cost: The corrosion resistance reduces the need for coating or replacement.
The performance degradation of a heat exchanger is essentially due to two phenomenons which occurs over time :
- Increased fouling resistance due to impurity accumulation contained in both fluids.
- Increased thermal resistance at the tube-to-fin bond due to thermal cycling dilatation of the materials and to corrosion at the fin base or root. These factors creates a loss of contact or bond pressure in between the fins and the tube.
| Type | Description | Base tube | Fin specification (mm) |
| O.D. (mm) | Fin pitch | Fin height | Fin thick |
| Embedded | G-type fin tueb | 16-63 | 2.1-5 | <17 | ~0.4 |
| Extruded | Single metal combined metal | 8-51 | 1.6-10 | <17 | 0.2-0.4 |
| Low fin tube t-type fin tube | 10-38 | 0.6-2 | <1.6 | ~0.3 |
| Bamboo tube corrugated tube | 16-51 | 8-30 | <2.5 | / |
| Wound | l/kl/ll type fin tube | 16-63 | 2.1-5 | <17 | ~0.4 |
| String | String fin tube | 25-38 | 2.1-3.5 | <20 | 0.2-0.5 |
| U-type | U-type tube | 16-38 | / | / | / |
| Welding | HF-welding fin tube | 16-219 | 3-25 | 5-30 | 0.8-3 |
| H/HH type fin tube | 25-63 | 8-30 | <200 | 1.5-3.5 |
| Studed fin tube | 25-219 | 8-30 | 5-35 | φ5-20 |
Application
Air Cooler
The exhaust steam condensation of steam turbines in power plants and the cooling of process gases in petrochemical plants rely on the lightweight and atmospheric corrosion resistance of aluminum fins.
Air conditioning and refrigeration systems
Aluminum fin tubes in evaporators and condensers can reduce equipment weight and improve the energy efficiency ratio (COP).
Thermal management of new energy vehicles
Battery coolers and motor radiators use the lightweight advantages of aluminum fins to extend driving range.
Industrial waste heat recovery
In flue gas waste heat recovery devices, aluminum fins are resistant to acid dew point corrosion and can adapt to complex working conditions.
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ASTM A312 ASME SA312 Stainless Steel Gombined Metal Extruded Fin Tube For Heat Exchanger Images
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