The working principle of medium frequency heating furnace

The medium frequency heating furnace is an induction heating device for the purpose of heating metal forging or quenching and tempering heat treatment. When used for heating before forging, the heating temperature is generally 1200 degrees, and when used for quenching and tempering heating, the heating temperature is generally within 1000 degrees. The purpose of this medium frequency heating determines that the heating of the medium frequency heating furnace is only for heating, not for melting the metal. Therefore, the medium frequency heating furnace is different from other types of heating furnaces in terms of structure and principle.

1. The basic principle of the medium frequency heating furnace is electromagnetic induction heating, which follows the electromagnetic effect theory, such as electromagnetic ring effect, skin effect, sharp corner effect, proximity effect, diathermy effect, conduction effect and so on.
2. The medium frequency heating furnace is mainly composed of a frequency conversion device and an induction coil. The frequency conversion device converts the power frequency 50Hz alternating current into the medium frequency 100Hz to 10000H alternating current, rectifies the three-phase power frequency alternating current into direct current, and then turns the direct current into adjustable The medium-frequency current is supplied by the medium-frequency alternating current flowing in the capacitor and the induction coil, which generates high-density magnetic lines of force in the induction coil, and cuts the metal material contained in the induction coil, which generates a large eddy current in the metal material.
3. The existence of the frequency conversion device and induction coil of the medium frequency heating furnace enables eddy currents to be generated in the heated metal materials, which also have some properties of medium frequency currents. For example, the flow of free electrons in the metal itself in a resistive metal body generates heat. For example, if a metal cylinder is placed in an induction coil with alternating medium frequency current, the metal cylinder is not in direct contact with the induction coil, and the temperature of the energized coil itself is already very low, but the surface of the cylinder is heated to redness or even Melting, and the speed of redness and melting can be achieved only by adjusting the frequency and the strength of the current. If the cylinder is placed in the center of the coil, the temperature around the cylinder is the same. Heating and melting of the cylinder will not produce harmful gases or pollute the environment with strong light, which is very friendly to the surrounding environment.