In 1899, Sweden manufactured the world's first induction melting equipment - an induction furnace. By the 1930s, induction furnaces were widely used for melting black and non-ferrous metals. After World War II, the era of power frequency induction furnaces emerged. Due to its ability to be directly connected to the 50Hz or 60Hz main power grid, power frequency furnaces have experienced a period of rapid development as melting equipment in the foundry industry. It gradually replaced the blast furnace, gas furnace, and oil furnace.
Induction melting achieved significant breakthroughs in the 1980s with the development of static variable frequency power supply technology. With the introduction of thyristor technology, the frequency conversion efficiency of induction furnaces has increased from 60% -80% to 97% -98%, while achieving higher operational reliability and start-up rate. Compared with the power frequency furnace, the power density of the medium frequency furnace is about three times that of the power frequency furnace, and there is no need for residual liquid or power reduction during the melting process, which can ensure constant power operation.
In recent years, the rapid development of downstream industries such as automotive parts, machinery, clean energy, and aerospace has led to an increasing demand for castings, resulting in a growing market demand for induction furnaces. Compared to the blast furnace, the medium frequency induction furnace has controllable chemical composition and temperature of the molten iron, and produces less harmful substances such as sulfur content and slag dust in the molten iron, making it more energy-efficient and environmentally friendly. Currently, it has basically replaced the blast furnace as a standard melting equipment in the casting workshop
