Induction furnace converts three-phase power frequency alternating current into direct current after rectification, and then converts the direct current into adjustable medium frequency current. The medium frequency current flowing through the capacitor and induction coil generates high-density magnetic lines of force in the induction coil, cuts the metal in the induction coil, and generates a large eddy current in the metal. This eddy current also has some properties of medium frequency current, that is, the free electrons of the metal itself flow in the metal body with resistance to produce heat.
For example, a metal cylinder is placed in an induction coil with alternating medium frequency current. The metal cylinder is not in direct contact with the induction coil. The temperature of the energized coil itself is very low, but the surface of the cylinder is heated to redness or even melting. Moreover, this redness and melting speed can be realized as long as the frequency and current strength are adjusted. If the cylinder is placed in the center of the coil, the temperature around the cylinder is the same, and the cylinder heating and melting do not produce harmful gas and strong light to pollute the environment.
Because induction furnace has the above advantages, it has been widely used.
For example, in the roll industry: in the past, most roll factories used cupola coke furnace to smelt molten iron. The composition of molten iron from cupola can not be adjusted, the temperature is difficult to control, the cast roll quality is poor, the yield is low and the benefit is poor. Moreover, the molten iron temperature of this cupola can not rise to 1600 ℃, so it can not produce high-grade steel rolls, which makes China's high-grade rolls rely on imports.
Nowadays, the induction furnace is used to smelt molten iron to produce rolls, which has raised the roll production level to a big level and achieved obvious benefits.
In the foundry industry, power frequency furnaces were used to smelt molten iron and steel. Because the frequency of 50 cycles of power frequency is too low, it is difficult to compensate the power after the first boiler is started. It can only be compensated slowly. It takes a few hours to output full power, wasting time and reducing efficiency. After the molten iron is smelted, the molten iron cannot be completely poured out, and some molten iron needs to be left in the furnace, otherwise the smelting cannot be started for the second time. Due to the low frequency, the molten iron rolls too much in the furnace, stirring the slag and inclusions in the liquid, which affects the quality of molten steel.
Now, after the power frequency furnace is changed to medium frequency induction furnace, the benefit is significantly improved, so the power frequency furnace is gradually eliminated by the smelting industry.
In the early days of the smelting industry, electric arc furnaces were also widely used. This kind of equipment is that electrodes are short circuited with each other through carbon rods to produce short-circuit large current, and then produce high temperature to melt molten iron or steel. The disadvantage of this equipment is that it will produce dazzling arc light when generating high temperature, stab the operator's eyes, produce harmful powder gas and pollute the environment. When generating high temperature above 1000 ℃, it will also burn the precious elements in molten steel, reduce the effective yield of molten steel and elements, increase the cost and burn the furnace wall at the same time. Especially the lining life of small tonnage electric furnace is very low.
Yiphee Electric Furnace Co.,Ltd specializes in producing induction smelting furnace.Tel(WhatsApp):+86-13450756789, email@example.com