What are the classifications of industrial electric furnace transformers?
Electric furnace transformerIt is a transformer designed for power supply of various electric furnaces. Industrial electric furnace transformers can be divided into three categories: resistance furnace transformers, electric arc furnace transformers and induction furnace transformers. Mechanical parts heating, heat treatment, metallurgical sintering, non-ferrous metal exercise resistance furnace, resistance furnace transformer for salt bath furnace. Because the resistance of the heating element is too small, or the resistance of the heating element is too large during the heating process, it is necessary to equip a resistance transformer between the furnace and the grid to reduce and adjust the input voltage of the furnace.
1. Resistance furnace transformer
Used for heating mechanical parts, heat treatment, powder metallurgy sintering, non-ferrous metal electric furnace transformer, metal exercise resistance furnace and salt bath furnace. Because the resistance of the heating body is too small, or the resistance of the heating body is changed too much during the heating process, it is necessary to equip the resistance furnace transformer between the heating furnace and the power grid to reduce and adjust the input voltage of the heating furnace. Transformers for small-capacity, low-voltage resistance furnaces and salt-bath furnaces are mostly dry-type transformers with shells and natural cooling; transformers for medium-capacity resistance furnaces are oil-immersed self-cooling transformers. The large capacity is a forced oil circulation water-cooled transformer.
2. Electric arc furnace transformer
Special transformer for steel-making electric arc furnace. Large capacity, complex structure and high technical requirements. Its side voltage is generally between tens and hundreds of volts, and it can be adjusted in a wide range; the side current is often between thousands and tens of thousands of amperes. In addition, in the steelmaking process, the smelting cycle requires high power, requiring the transformer to be overloaded 2 0% within 2 hours. In the steelmaking process, because the furnace charge collapses, it is easy to cause a short circuit. Therefore, the primary side of the arc furnace transformer should be connected to the current limiting reactor, or it should have a larger furnace transformer impedance to limit the short circuit current. The operation of the electric furnace also requires that the power transformer can regulate the voltage. There are two methods for adjusting the voltage of an electric furnace transformer.
3. Induction furnace transformer
The induction furnace used for smelting ferrous and non-ferrous metals is essentially a special furnace transformer induction furnace with two types of iron core and iron-free core. Induction furnace with iron core is a transformer with iron core and short-circuit secondary winding. The primary winding of the transformer is connected to the power supply, and the secondary winding actually only needs one turn. When the primary winding is connected to the current, the secondary winding will induce current and circulate in the slot, then release heat and melt the metal.
4. Structural characteristics
The iron core of the electric furnace transformer is made of high-quality oriented silicon steel sheet, fully automatic cutting line processing, 45 degree full oblique seam, no punching, no weft glass tape binding process. The coil uses the world's new main longitudinal insulation structure. Reasonably select the structure and insulation of the winding to ensure that the winding has satisfactory mechanical strength. It has the characteristics of strong short circuit resistance, strong overload capacity, high efficiency, low loss, safety and reliability.
The capacity of the electric furnace transformer is equipped according to the size of the electric arc furnace and the exercise technology. By adjusting the pressure can meet the requirements of exercise technology. Voltage regulation can be divided into load voltage regulation and non-excitation voltage regulation. Large-scale furnace transformers with on-load voltage regulation have no series reactors, and small and medium-sized furnace transformers without excitation voltage regulation can be divided into two structures with series reactors and no reactors, and the impedance can be changed at very high two voltages. The former changes the impedance through the input and removal of the series reactor. The latter changes the impedance of the high-voltage winding by changing the connection method of the transformer itself.
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