Small-sized Medium-Frequency Induction Melting Furnace Equipment

MF Induction Heating Power Supply

Medium-frequency induction heating power supplies (typically with a frequency range of 1–10 kHz) are devices that heat metals using the principle of electromagnetic induction. They are suitable for industrial applications such as heat penetration, melting, forging, and annealing. Compared with high-frequency heating, medium-frequency heating offers greater penetration depth, making it ideal for processing thicker metal workpieces.

1. Working Principles of Medium-Frequency Induction Heating Power Supplies

• Electromagnetic Induction: Medium-frequency alternating current (1–10 kHz) passes through an induction coil to generate an alternating magnetic field, inducing eddy currents within the metal workpiece to produce heat.
• Skin Effect: Current concentrates on the workpiece surface but penetrates deeper (1–10 mm) than high-frequency heating, making it suitable for larger workpieces.
• Heat Penetration Effect: Ideal for scenarios requiring overall heating, such as forging and melting.

2. Main Components and Their Functions

Product Overview

This medium frequency induction heating system is designed around the series-resonant inverter structure, consisting of a MF power supply, a compensation capacitor box, and a customized induction coil. It is a high-efficiency, cost-effective solution widely used in metal melting, heat treatment, and thermal fitting applications.

Technical Highlights

Technical Explanation

The system works on LC series resonance, where the induction coil (L) and capacitor box (C) form a resonant circuit. At resonance, impedance is minimized, and current is maximized—allowing efficient energy transfer to the workpiece via eddy current heating.

However, the design also has several limitations:

• Induction coil length is typically long (3–10 meters of copper tubing)
• The coil is directly connected to high-voltage output (up to 550V) and is not isolated from the grid
• In vacuum applications, the coil may cause glow discharge, so insulation is critical (high-temp tape, ceramic mud, varnish, or shielded enclosure required)