A Bent Fin Tube, also called a Bend Finned Tube, is a custom-shaped heat exchange device made of multiple finned tubes connected by elbows. Its core structure consists of finned tube units, steel elbows, and connecting fittings. Customizable to accommodate complex spatial layouts, the following are its key features and applications:
1. Bent Fin Tube Structural Features
Finned Tube Unit
The base tube is typically made of steel, stainless steel, or copper. Fins are applied to the surface through high-frequency welding and spiral winding, significantly increasing the heat dissipation area. Fin spacing, height, and material (such as steel-aluminum composite) can be adjusted according to needs.
Elbow Connections
90°, 180°, or U-shaped elbows can be welded or flanged to create L-shaped, serpentine, and other special-shaped flow paths, addressing the installation limitations of traditional straight-tube radiators in confined spaces.
II. Bent Fin Tube Performance Advantages
High-Efficiency Heat Exchange: Fins expand surface area, and elbows reduce fluid stagnation, improving heat exchange efficiency by over 30%.
Spatial Adaptability: Flexible fit within irregularly shaped areas such as industrial plant corners and equipment gaps, eliminating wasted space.
Durability: The steel elbow, combined with a corrosion-resistant base tube (such as stainless steel), offers a pressure resistance of up to 2.0 MPa and is suitable for environments ranging from -40°C to 800°C.
III. Bent Fin Tube Application Scenarios
Industrial Applications: Chemical reactor perimeters, drying rooms, and waste heat recovery systems. Suitable for high-temperature media such as steam and thermal oil.
Civil Applications: Elevator shafts and heating systems for special-shaped venues, achieving stable temperature control through hot water circulation.
IV. Bent Fin Tube Customization Options
Material Options: Carbon steel, stainless steel, or ND steel to meet corrosion and wear resistance requirements.
Arrangement: Supports staggered (high heat transfer efficiency) or sequential (low fluid resistance) layouts. The number of layers can be increased to four or more.
The service life of bent fin tubes is affected by multiple factors, including material, process, operating environment, and maintenance level. These factors are as follows:
V. Relationship between Bent Fin Tube Material and Lifespan
Carbon Steel Galvanized Bent Fin Tube
Hot-dip galvanized carbon steel bent fin tubes have a service life of 8-10 years in dry, lightly dusty environments, but this may be reduced to 5-8 years in humid environments.
Stainless Steel (304/316L) Bent Fin Tube
316L stainless steel has a service life of over 15 years in highly corrosive environments (such as chemical plants), while 304 can last over 20 years in residential applications.
Steel-Aluminum Composite Bent Fin Tube
Suitable for low-temperature, lightweight applications (such as elevator shafts). Its design life is typically 10-15 years, but strong alkaline environments can significantly shorten its service life.
VI. Bent Fin Key Factors Affecting Tubes
Corrosive Environment: Coastal salt spray or chemical acid and alkali gases can shorten the life of aluminum fins by over 50%.
Temperature and Pressure: Prolonged high temperatures (>300°C) or high pressures (>1.5 MPa) accelerate material aging.
Joining Process: High-frequency welding extends life by 30% compared to traditional winding, and the integral rolling process prevents crevice corrosion.
VII. Bent Fin Tube Maintenance Recommendations
Regularly clean dust from the fins to prevent increased thermal resistance.
In humid environments, it is recommended to inspect the integrity of the galvanizing or anti-corrosion coating annually.
Typical Application Cases: 316L stainless steel U-bent fin tubes at a pesticide factory remained rust-free for three years in a 120°C steam environment, while galvanized carbon steel L-shaped fin tubes at an automobile factory remained trouble-free for two years in 95°C hot water heating.