The technology of smelting metals by induction heating has developed over a hundred years, it continues to improve until now. It all began with the discovery by the scientist M. Faraday of the phenomenon of electromagnetic induction. Already at that time, the first practical attempts were made to create a new technology for smelting metals in laboratory conditions, but all of them ended in failure. At that time there were no installations capable of generating high-frequency currents of sufficient power.
The first induction furnace was proposed by S. Farranti in 1887. But before the time of its practical implementation a lot of time passed. In 1890, the company Benedicks Bultfabrik realized this idea, there was a real opportunity on an industrial scale to carry out the smelting of metals using new technology. But at that time there were no powerful sources of current, therefore, the induction furnace worked with insignificant volumes of metal.
The situation began to change at the beginning of the 20th century, when the design of the furnace underwent significant changes. Powerful generators and current sources of increased frequency appeared, which began to be used to ensure its operation.
The development of
semiconductor devices and the appearance of the first
thyristor converters made it possible to create efficient power systems based on them. A modern induction furnace is able to work with large volumes of metal. Through the use of innovative control systems, it has become more economical.
This technology allows to obtain ultrapure alloys of various metals. If in the traditional method of melting, for example, in the converter, a large percentage of impurities remains, then when using this method they are absent. This allows you to create ultra-pure alloys with good performance.
The principle of operation of an induction furnace, which consists in non-contact heating of metals using an
electromagnetic field, is interesting
. This happens with the help of an inductor, the load of which is the metal loaded into the furnace. If the furnace capacity is high enough, then melting occurs.
The induction furnace itself can have a wide variety of dimensions and purposes. It can be used in laboratory installations or large industrial complexes, have different power and performance.
A small home-made induction furnace may well come in handy in the home laboratory. Using it, you can make, for example, solder with different contents of zinc and tin, as well as much more. In its manufacture, the above-described principle of operation must be taken into account. Use a high-frequency generator (from 30 MHz and above), a powerful power source, power modules, and as a result, a piece of zinc can be melted in a crucible (it can consist of 6-15 turns of PEV-8.0 wire) in a short period of time (15 -20 seconds).
The development of this technology follows the path of gradually increasing the capacity of plants, improving the elemental power base, increasing the frequency of the generator and using innovative developments in control, monitoring and protection schemes.