The historical origin of induction heating equipment

Induction heating comes from the phenomenon of electromagnetic induction discovered by Faraday, that is, an alternating current will generate an induced current in a conductor, which will cause the conductor to heat up. In 1890, Swedish technicians invented the first induction melting furnace, the slotted core furnace. In 1916, the Americans invented the closed slot cored furnace. Since then, the induction heating technology has gradually entered the practical stage.

The rapid development of power electronic devices and technologies in the 20th century has greatly promoted the development of induction heating technology.

In 1957, the United States developed the thyristor as a milestone in power electronic devices, marking the beginning of modern power electronic technology and also triggering a revolution in induction heating technology. In 1966, Switzerland and West Germany first used thyristors to develop induction heating devices. Since then, induction heating technology has developed rapidly.

After the 1980s, power electronic devices developed rapidly again, and devices such as GTO, MOSFET, IGBT, MCT and SIT appeared one after another. Induction heating devices also gradually abandoned thyristors and began to use these new devices. Now more commonly used are IGBT and MOSFET, IGBT is used for higher power occasions, and MOSFET is used for higher frequency occasions. According to reports, IGBTs can be used abroad to make induction heating devices with a power exceeding 1000kW and a frequency exceeding 50kHz. The MOSFET is more suitable for high frequency occasions, usually used in small and medium power occasions of several kilowatts, and the frequency can reach more than 500kHz, or even several megahertz. However, there are also high-power induction heating devices using MOSFETs abroad, such as the 2000kW/400kHz device developed in the United States.

The real application of induction heat treatment technology in my country began in 1956, introduced from the former Soviet Union, mainly used in the automobile industry. With the manufacture of power equipment in the 20th century, induction hardening process equipment has also been developed. At present, the domestic induction hardening process equipment manufacturing industry is also expanding, and there are many varieties of products. The equipment that originally needed to be imported is gradually replaced by domestic products. While saving foreign exchange for the country, domestic related enterprises have been developed. At present, the service object of the induction heating manufacturing industry is mainly the automobile manufacturing industry. In the future, the modern metallurgical industry will have a greater demand for induction heating.