Induction melting furnace accessories
The medium frequency induction furnace uses a copper tube single-layer roll to form an induction coil, and in the water-cooled induction coil, there is a refractory knotted crucible for accommodating the molten metal. The induction furnace usually consists of four parts: the power supply, the furnace body (mainly the induction coil and the enamel made of refractory material in the induction coil), the capacitor bank (used to improve the power factor), the control and the operating system.
1. Induction furnace body part
(1) Induction coil induction coil: The induction coil is the heart of the induction furnace. The electromagnetic energy is converted into thermal energy through the induction coil, and the metal charge in the crucible is melted. The rectangular copper tube is wound into a multi-turn coil and has a spiral shape. Spray high-strength insulating varnish and wrap it with insulating tape. Between the intermediate frequency furnace and the crucible, refractory mortar is applied, and a water-cooling ring is arranged above and below the induction coil.
(2) The yoke of the induction furnace: the yoke is stacked by high-quality silicon steel sheets, distributed around the periphery of the induction coil, and functions as a support skeleton, and also acts to restrain the magnetic flux leakage outside the induction coil to prevent the metal components from heating.
(3) Water-cooled cable for induction furnace: Because the tilting furnace frequently causes the broken wire of the water-cooled cable to break, and the connection bolt at the terminal end may loosen, the current imbalance may be caused. Generally, the life of the water-cooled cable is determined to be three years according to the number of times of the furnace. It needs to be replaced after three years. If the bolt is discolored, it needs to be updated and tightened in time.
(4) Furnace lining of induction furnace: Induction furnace has high temperature in production, large temperature change of furnace, and also suffers from slag erosion and electromagnetic stirring. High-temperature molten iron directly washes lining of furnace, lining is easily damaged, and the cost of building furnace is high, and the induction is prolonged. The service life of the furnace lining and reducing the frequency of furnace construction are very important for reducing the cost.
(5) Induction furnace's leaking furnace alarm device: In order to ensure safe production and prevent leakage accidents from occurring and expanding, it is helpful to judge the use of the furnace lining, extend the furnace age, and set up the leaking furnace alarm system. Generally, a DC type alarm device is used, and a stainless steel wire bottom electrode (first electrode) in contact with molten iron and a stainless steel plate (mesh) side electrode (second electrode) in which the furnace liner is inductively are respectively mounted.
2. Induction furnace hydraulic system
It consists of hydraulic device, console, tilting cylinder, and lid hydraulic cylinder. Regularly check whether there are leakages in the seals of the hydraulic system. If it is found that the seals should be replaced, the lubrication parts should be lubricated regularly with lubrication (the rotary self-lubricating spherical bearings of the tilting furnace should be added to the old when filling the grease). If the oil overflows, it will be very easy to cause damage.
3. Induction furnace water cooling system
Ensure the quality of the cooling water and check the scale regularly. If there is scale, clean it immediately to ensure the cooling effect. The cooling water quality requirements of general power frequency furnace: pH value is 6-9, hardness <10mg equivalent/L, total solid amount does not exceed 250mg/L, cooling water temperature rises <25°C; water quality of cooling water used for intermediate frequency power supply The pH is 7-8, the hardness is <1.5 mg equivalent/L, the suspended solids are 50 mg/L, and the electrical resistivity is >4000 Ω·cm. The circulating water in the circulating pool should be tested regularly. When the circulating water hardness exceeds 2mg equivalent/L, the circulating water in the system should be emptied and replaced. The cooling tower should be drained regularly to exchange for new soft water to prevent blockage of the pipes and nozzles, affecting the cooling effect and the service life of the lining.
4. Induction furnace electronic control system
The main circuit and the induction coil should regularly clean the surface dust. The conductive metal dust in the foundry workshop and the iron beans splashed when the iron is discharged on the surface of the main copper bar or the induction ring will cause the insulation ability to be reduced, resulting in discharge and ignition. Causes damage to electrical components. It can be blown off using compressed air without water. The main circuit copper busbar connection screws also need to be checked and tightened regularly. Otherwise, due to the increase of contact resistance, large heat will be generated at the joint to cause carbon leakage of the insulation material to cause leakage.
