High-Frequency Welding Finned Tube

Finned tubes, designed to enhance heat transfer efficiency, involve adding fins to the surface of heat transfer tubes. The introduction of fins increases the outer (or inner) surface area of the heat transfer tube, thereby improving heat transfer efficiency and altering the heat pipe. High-frequency welding finned tubes, specifically spiral finned tubes, are widely utilized across various industries including electricity, metallurgy, cement, waste heat recovery, and petrochemicals. This technology is considered highly advanced due to its superior product quality, automation, and productivity.

Features of High-Frequency Welding Finned Tubes:

1. Spiral Finned Tubes:

   - The most widely used type of finned tube.

   - Utilized in electricity, metallurgy, cement, waste heat recovery, and petrochemical industries.

2. Welding Process:

   - High-frequency welding involves wrapping a steel strip around a steel pipe.

   - Utilizes high-frequency current skin effect and proximity effect to heat the outer surface of the pipe until it reaches a melted or plastic state.

   - Pressure is applied to complete the welding process.

3. Solid Phase Soldering:

   - High-frequency welding results in a solid-phase soldering, contributing to enhanced product quality.

4. Advantages over Other Methods:

   - Superior product quality with a welded high fin efficiency reaching up to 95%.

   - Advanced automation and higher productivity compared to inlay, soldering, or overall hot dip galvanizing methods.

Principles of High-Frequency Welding:

1. Skin Effect:

   - Uneven current distribution in the conductor, with increasing current density from the center to the surface.

   - Most of the current flows along the surface, especially in conductors with low resistivity and high permeability.

2. Proximity Effect:

   - Current concentration in a specific conductor near the side flows when high-frequency current flows back and forth or in a single direction.

High-Frequency Welding Finned Tube Parameters and Characteristics:

1. Frequency Range:

   - Normally used frequency range for high-frequency welding is 300 ~ 450kHz, with occasional use of low frequency (10kHz).

2. High-Frequency Welding Features:

   - Welding speed provides a self-cooling effect, resulting in a small heat-affected zone.

   - Excellent organization and properties of the weld due to oxidation resistance.

   - Notable features include corrosion resistance, wear resistance, low contact resistance, high stability, and anti-fouling ability.

   - Large heat transfer area.

Types of High-Frequency Welding:

1. High-Frequency Resistance Welding:

   - Utilizes scroll wheel or touching the child as an electrode for longitudinal seam welding of pipes and spiral lap seam welding.

   - Suitable for boiler tubes, fin heat exchanger fin spiral welding, with high productivity.

2. High-Frequency Induction Welding:

   - Involves induction heating coil for welding small diameter and thin-walled pipes.

   - Commonly used in vertical small diameter steel pipe and brass seam welding.

   - Parameters affecting welding quality include high-frequency power frequency, power, forming the workpiece angle, distance, welding speed, extrusion pressure, and electrodes.

High-Frequency Welding Finned Tube Applications and Conclusion:

- High-frequency welding finned tubes find applications in various sectors, contributing to energy efficiency and cost savings.

- Stability in quality, high productivity, and low costs make high-frequency welding an advanced and preferred method for slit tube production in efficient automatic production lines.

High-frequency welded finned pipe