Talk about the future development trend of medium frequency induction heating power supply

Due to the rapid development of modern machinery manufacturing and metallurgical industry, three major requirements have been put forward for castings: high quality, refinement and energy saving. In order to meet these requirements, the current development trends of medium frequency induction heating power supplies are as follows.

(1) The application of medium frequency induction heating power supply is expanding day by day.

The advantages of medium frequency induction heating power supply are:

① It has high power density, fast melting speed, convenient melting, and is suitable for energy-saving batch melting methods. The melting unit consumption of a medium frequency induction electric furnace with the same capacity is lower than that of a power frequency induction electric furnace.

② The operation is flexible and convenient, and it is suitable for sites where the types of molten metal are often changed.

③Selectable power frequency makes the medium frequency induction furnace more suitable for melting light metals.

④ Due to high power density, no phase balance device, and low civil construction costs, the initial investment cost of a medium frequency induction electric furnace with the same productivity is 10% to 15% lower than that of a power frequency induction electric furnace. It is precisely the above advantages that medium frequency induction furnaces have basically replaced power frequency induction furnaces abroad (except for trench induction furnaces), and they also show a trend of replacing power frequency induction furnaces in China.

The current medium frequency induction heating power supply has the following significant features compared with the traditional thyristor power supply:

Compared with thyristor medium frequency induction heating power supply, it saves 10%-30% energy.

The power factor is high, always greater than 0.95, and the high-order harmonic components are small, which has little impact on the power grid.

The equipment can be connected and used with various power and temperature control systems to greatly improve product quality.

Using automatic frequency locking circuit, it can start successfully 99% of the time under any load.

Using IGBT resonant frequency conversion technology, the conversion efficiency is over 97.5%.

(2) The application of crucible induction furnaces has been expanded to the field of cast iron insulation

Crucible induction furnaces (including short-coil induction furnaces and medium-frequency crucible-type induction furnaces) have the advantages of flexible use; adjustable electromagnetic stirring force; convenience in adjusting the composition of molten iron and controlling the temperature of the molten iron; and easy replacement of furnace lining refractory materials, making crucible-type induction furnaces Electric furnaces are increasingly used as cast iron insulation.

(3) The application of pouring furnaces with induction heating devices is rapidly expanding. With the emergence of various high-efficiency casting production lines, the requirements for mechanization and automation of the pouring process have become more urgent. Accurate pouring temperature is an important condition to ensure high-quality castings. A pouring furnace that can store a certain amount of molten metal is conducive to organizing production. Therefore, in recent decades, various countries have successively developed pneumatic, plug-rod, pneumatic-plug-rod and electromagnetic pump-type thermal insulation pouring furnaces, which have rapidly changed the backwardness of the casting and pouring process, improved the quality of castings, reduced waste, and achieved achieved good economic results.