Electric induction furnace is a kind of power supply device that converts the power frequency of 50 Hz AC into an intermediate frequency (300 Hz to 20 kHz). It converts the three-phase power frequency AC into direct current after rectification, and then converts the direct current into adjustable intermediate frequency current to supply the intermediate frequency alternating current flowing through the capacitor and induction coil, generating high-density magnetic lines of force in the induction coil, and cut the metal material in the induction coil, which produces a large eddy current in the metal material.
This kind of eddy current also has some properties of intermediate frequency current, that is, the free electrons of metal flow in the metal body with resistance to generate heat. For example, if a metal cylinder is placed in an induction coil with alternating medium frequency current, the metal cylinder does not directly contact with the induction coil, and the temperature of the coil itself is very low, but the surface of the cylinder is heated to reddening or even melting, and the reddening and melting speed can be achieved by adjusting the frequency and the current strength. If the cylinder is placed in the center of the coil, the temperature around the cylinder is the same, and the heating and melting of the cylinder do not produce harmful gas and strong light pollution.
Electric induction furnace series smelting furnace features:
1. High melting efficiency, good power-saving effect, compact structure and strong overload capacity.
2. The temperature around the furnace is low, the dust is less, and the working environment is good.
3. The operation process is simple and the smelting operation is reliable.
4. The metal composition is uniform.
5. Fast melting temperature rise, easy furnace temperature control and high production efficiency.
6. The utilization rate of the electric induction furnace is high, and the variety change is convenient.
7. The long arc yoke shields the magnetic flux leakage and reduces the external magnetic resistance, the magnetic flux leakage at both ends of the shielded coil, and the inner side of the yoke section is in the arc, which is close to the outer wall seamlessly, increasing the effective permeability area and making the lower coil obtain better support. The unique positive and negative rotation coil greatly improves the efficiency of the system.
Electric induction furnace series diathermy furnace features:
1. Fast heating speed, high production efficiency, less oxidation and decarbonization, saving material and forging die cost.
2. Superior working environment, improving workers’ working environment and company image, no pollution and low energy consumption.
3. Uniform heating, minimum temperature difference between core and surface, high-temperature control accuracy.
The electric induction furnace heating device has the advantages of small volume, lightweight, high efficiency, excellent thermal processing quality and favorable environment. It is rapidly eliminating the coal-fired furnace, gas furnace, oil furnace and ordinary resistance furnace. The intermediate frequency furnace is a new generation of metal heating equipment.
Electric induction furnace is the main equipment of casting forging and heat treatment workshop. Its working stability, reliability and safety are the guarantee of normal and stable operation of casting forging and heat treatment production line.
Electric arc furnace is an electric furnace for smelting ores and metals with high temperature generated by electrode arc. When the arc is formed by gas discharge, the energy is concentrated and the temperature of the arc zone is above 3000 ℃. For smelting metals, EAF is more flexible than other steelmaking furnaces, which can effectively remove sulfur, phosphorus and other impurities. The furnace temperature is easy to control, and the equipment covers a small area. It is suitable for smelting high-quality alloy steel.
According to the form of an arc, EAF can be divided into three-phase EAF, consumable EAF, single-phase EAF and resistance EAF. The furnace body of EAF is composed of furnace cover, furnace door, tapping tank and furnace body. The furnace bottom and wall are built with basic refractory or acid refractory. According to the transformer capacity per ton of EAF capacity, EAF can be divided into ordinary power EAF, high power EAF and ultra-high power EAF.
EAF steelmaking is to input electric energy into EAF through graphite electrode, and take the arc between electrode end and charge as heat source for steelmaking. Electric energy is used as the heat source in EAF, and the atmosphere in EAF can be adjusted, which is very beneficial to the smelting of steel grades with more oxidizable elements. Shortly after the invention of EAF steelmaking, it was used to smelt alloy steel and developed greatly.
With the improvement of electric arc furnace equipment and smelting technology, the development of the electric power industry, the cost of electric arc furnace steelmaking is constantly decreasing. Now electric arc furnace steelmaking is not only used for the production of alloy steel, but also for the production of ordinary carbon steel, and its proportion in the total output of steel in major industrial countries is rising.
The cost of an electric arc furnace is very expensive, but the product quality is good. The common frequency furnace consumes the most electricity. The medium frequency furnace is 800-900 degrees / T below 2000kW, and the large furnace is 600-700 degrees / T. These are just normal conditions. In addition, human factors (operation proficiency, equipment maintenance degree), aging of equipment, various compensation, harmonic control and other factors will affect the power consumption.
Compared with electric arc furnaces, electric induction furnace steelmaking has a lower cost and is suitable for small and medium-sized enterprises (small workshops). However, the steel produced by a medium frequency furnace is impure due to its high impurity and high carbon content. If the requirements are not high, medium-frequency furnace steelmaking can be selected. The volume of electric arc furnaces is large, generally, more than 3 tons, so only enterprises with a certain scale can use electric arc furnaces, and the steel which makes is relatively pure.
The electric arc furnace uses the power frequency electricity, while the electric induction furnace uses the medium frequency electricity.
