1. The status quo of induction heating abroad

With the development of power semiconductor devices and power electronic technology, the appearance of induction heating devices is also changing with each passing day, especially the changes in the volume, quality, and performance of the device. For example, the transistor type frequency conversion device of the same capacity is reduced by 2/3 in volume, 2/3 in weight, 1/2 in cooling water, 1/3 in power consumption, and 35% in efficiency compared with the tube-type frequency conversion device. It has a longer service life, is safer and more reliable, and is easy to realize automatic control. It is helpful to improve heating efficiency and quality. In addition, induction heating device has a smaller maintenance workload and can be opened at any time.

The technological development and induction heating application devices in industrially developed countries such as Germany, the United States, the United Kingdom, France, Japan, Italy, Spain, Belgium, and Russia are in the forefront of the world.

2. Domestic development and current situation

The application of domestic induction heating technology began in the 1950s, and the development was mainly after the reform and opening up, and it was mainly used in the manufacturing of machine tools, automobiles, and tractors. Induction heating is concentrated on the surface quenching of the workpiece, while the application of smelting and diathermy is less. Almost all of the induction heating technology comes from the former Soviet Union and the Czech Republic. In the 1980s, Zhejiang University independently developed the first parallel thyristor intermediate frequency power supply and promoted it nationwide.

In the 1990s, some foreign induction furnace companies directly came to China to set up factories, such as Yingda Induction Heating Company and Bile Company in the United States, competing with domestic manufacturers in the same industry. Their products have high technology content, large power supply, complete brands, large furnace tonnage, and large production lines, occupying a large part of the domestic market. Only the high price of their equipment (approximately 1/5 of the price of domestic products with the same performance) has enabled domestic manufacturers to have a certain market development space.

3. Features of induction heating

(1) The induction heating temperature is high, and it is non-contact heating.

(2) High heating efficiency.

(3) Fast heating speed.

(4) The induction heating temperature is easy to control.

(5) It can be heated locally.

(6) It is easy to realize automatic control.

(7) The working environment is good, and there is almost no noise and dust.

(8) Less work area and high production efficiency

(9) It can heat workpieces with complex shapes.

(10) The workpiece is easy to heat evenly, and the product quality is good.

(11) The solution has electromagnetic stirring effect during smelting. The composition of the molten metal can be adjusted uniformly, and the temperature of the solution is uniform without local high temperature. Less metal burns, which is more important for smelting rare metals.