Stainless Steels Welded U Longitudinal finned tube

‌What is Stainless Steels U Longitudinal Finned Tube?‌

A longitudinal finned tube is a heat transfer enhancement component formed by adding metal fins axially (longitudinally) along the surface of a base tube. Its core characteristics and applications are as follows:

I. Stainless Steels U Longitudinal Finned Tube Structure and Principle

1. ‌Basic Construction‌

   • Uses a metal base tube (carbon steel, stainless steel, etc.) as the core, with longitudinally arranged fins (rectangular, corrugated, etc.) welded or rolled onto its outer surface 14.
   • Fins typically have a height of 5–30mm, thickness of 0.2–0.5mm, and spacing of 3.5–40mm. They significantly increase the heat transfer area (multiple times that of a bare tube) to boost thermal conduction efficiency 513.

2. ‌Heat Transfer Mechanism‌

   • Heat transfers from the fluid inside the tube (steam, thermal oil, etc.) through the base tube to the fins, then dissipates to the external medium (e.g., air) via convection/radiation 912.
   • The longitudinal design enables uniform heat transfer along the tube length, minimizing flow dead zones, making it suitable for high-flow fluids 23.

II. Stainless Steels U Longitudinal Finned Tube Core Advantages

• ‌High-Efficiency Heat Transfer:‌ Fins significantly enlarge the heat dissipation area, increasing the convective heat transfer coefficient by 40%–60% compared to bare tubes, especially effective under forced convection 910.
• ‌Low Flow Resistance:‌ The longitudinal structure reduces fluid turbulence; resistance is lower than helical finned tubes, suitable for complex conditions like dusty flue gas 37.
• ‌Corrosion Resistance:‌ Surfaces can be galvanized or made from stainless steel, extending service life in humid/corrosive environments 411.
• ‌High Structural Strength:‌ Processes like high-frequency welding ensure strong bonding between fins and base tubes, withstanding high pressure and temperature 412.

III. Stainless Steels U Longitudinal Finned Tube Manufacturing Process Classification

IV. Stainless Steels U Longitudinal Finned Tube Typical Application Scenarios

1. ‌Industrial Sector‌
   • ‌Waste Heat Recovery:‌ Used in flue gas/exhaust waste heat recovery systems to reduce energy consumption 37.
   • ‌Process Heat Transfer:‌ Core heat transfer element in heaters and coolers for petroleum and chemical industries 312.
2. ‌Civilian Sector‌
   • ‌Heating Systems:‌ Steel-aluminum composite longitudinal finned tube radiators, combining high thermal conductivity and structural strength, suitable for residential/commercial heating 213.
   • ‌Air Heaters:‌ Rapidly heat indoor air via forced convection 49.

V. Stainless Steels U Longitudinal Finned Tube Key Parameters for Selection

• ‌Base Tube Specifications:‌ Common outer diameters: 18mm, 25mm, 32mm (carbon steel/stainless steel seamless tubes) 13.
• ‌Fin Height:‌ 10mm, 12.5mm, 15mm (selected based on heat transfer requirements and space constraints) 13.
• ‌Fin Pitch (Spacing):‌ Too small impedes airflow; too large reduces heat dissipation area. Requires balancing flow resistance and heat transfer efficiency 913.

Longitudinal finned tubes, leveraging their directional heat transfer, low resistance, and high efficiency, continue to play a vital role in industrial energy savings and civilian heating. Their application potential in new energy and environmental protection fields is still expanding 38.