3T intermediate frequency melting furnace is mainly used for the smelting of ferrous metals. For example, steel, ductile iron, gray iron, steel alloy, iron alloy, etc. can also be used for the smelting of non-ferrous metals such as copper and aluminum.
A, the basic composition of the intermediate frequency melting furnace
2000kw intermediate frequency power supply (parallel inverter ) , resonant capacitor bank, 600mm2 water-cooled cable, 3T furnace body (steel or aluminum)
1 . Fast medium frequency melting furnace, standard power configuration is 2000KW/500HZ , high power configuration is 2500KW/500HZ , incoming line voltage is 660V , and intermediate frequency power supply output voltage is 1500V .
2 . The design of the IF power supply is user-friendly, with perfect protection measures such as overcurrent, overvoltage, phase loss, undervoltage, and high water temperature.
3 . The thickness of the medium-frequency melting furnace body is up to 20mm , the structure is firm, the wall thickness of the copper tube is 5mm , and it is stable and reliable after multi-layer insulation treatment.
4 . All water pipes of the medium frequency melting furnace are made of stainless steel pipes to avoid rust and scale, and the cooling effect is greatly improved.
5 . Energy saving, reasonable design and environmental protection requirements.
6 . The intermediate frequency melting furnace is mainly used in foundry enterprises and metallurgical industries.
B, IF power supply technology features and performance :
1, all-digital frequency power supply control circuit , a control chip scale integrated circuit connection is simple, the power supply is stable, reliable, low failure rate. Currently, it is the six-generation main control board of DU .
2 , IF power supply has a constant power output, the output will not affect the output power when the load changes, can save more than 10% than ordinary IF equipment .
3 , IF power protection function is perfect, with current and voltage double closed-loop regulation system, with over voltage, over current, current limit, voltage limit, equipment power failure and under voltage and straight through protection, water pressure shortage, lack of equal protection.
4 , with fault self-diagnosis function, equipment maintenance is convenient and simple.
5. The intermediate frequency power supply is a sweep-type zero-voltage soft start, and the resonant frequency is self-tracking.
6 , strong starting performance and load adaptability, can be started frequently under light and heavy load, the startup success rate is 100% .
7. The impedance regulator automatically adapts to the load change, so that the equipment parameters are always running at the optimum state.
8. The starting mode is swept-type zero-pressure soft start, which has no impact on the loop.
9 , The intermediate frequency melting furnace equipment will not damage the components when it fails under normal conditions.
C, furnace body introduction
The shell structure is divided into two structures: aluminum shell furnace and steel shell furnace body :
The small-capacity furnace shell is generally made of aluminum alloy, which has reasonable structure, small volume, convenient installation, simple maintenance and low maintenance cost.
The large-capacity furnace body shell adopts a steel frame structure, and the furnace body structure is composed of a furnace fixing frame and a furnace body, and the furnace fixing frame and the furnace body adopt an integral skeleton structure. The tilting of the furnace body is controlled by the hydraulic system, which is realized by lifting two hydraulic cylinders on both sides of the furnace body. The resetting of the furnace body is realized by the pressure generated by the self-weight of the furnace body.
The furnace body has a built-in yoke, and the yoke shield can reduce the magnetic flux leakage, prevent the furnace body from heating and improve the efficiency. At the same time, the yoke acts as a support for fixing the induction coil, so that the furnace body achieves high strength and low noise. The yoke is a crescent-shaped yoke made of cold-rolled silicon steel sheet and stainless steel splint. The joint surface of the iron core and the coil is a circular arc surface, and the pressing portion is a surface instead of a line in the past. Good, less magnetic leakage. After the silicon steel sheets are stacked, they are tightened with a special splint instead of a special threaded screw . This structure can make full use of the magnetic conductive area of the silicon steel sheet and reduce the possibility of local heat generation.
G, coil ( induction coil )
The coil is the heart of the intermediate frequency melting furnace . The induction coil generates a strong magnetic field under the action of current, which causes the metal in the furnace to generate eddy currents and generate heat. Coils are the key to converting electrical energy into heat, so the design of the coil is very important. The coil of the furnace is combined with the actual use of the intermediate frequency melting furnace . According to the principle of electromagnetic field, the better solution determined by the calculation of computer professional software, the error between the design power of the induction coil and the actual running power is not more than 5 %, and the insulation of the coil In particular, the inter-turn insulation is protected by an advanced insulation method, and the special clamping technology can effectively reduce the axial vibration of the coil. The inner wall of the induction coil is coated with imported high-temperature insulation material, and is equipped with a leak alarm system, which can effectively prevent the furnace from being worn. Optional furnace lining and ejection mechanism can quickly remove the damaged lining and facilitate the rapid furnace construction.