Various processes in the process of using intermediate frequency furnaces are also very important to the service life of the furnace. Improper operation may reduce the service life of the furnace. Therefore, we should pay attention to the following points in the use process.
1. In the process of use, if the furnace needs to be shut down for a long time due to faults and other reasons, the molten iron in the furnace should be emptied to avoid the damage of the furnace lining when the molten iron condenses; when the molten iron cannot be emptied and the molten iron has been condensed, the furnace should be dismantled for the sake of safety, because it is impossible to judge whether the furnace lining is in good condition.
2. When the medium frequency furnaces are shut down for cooling, in order to avoid the sudden cooling of the furnace lining, the empty furnace cooling should be carried out. At the same time, in order to avoid cracks caused by the excessive temperature difference between the upper and lower parts of the furnace lining during the cooling process, the furnace cover should be covered to make the furnace lining be even.
3. Due to the inevitable occurrence of vertical cracks when furnace cooling, it is necessary to dry the furnace at low temperature before melting, so that the cracks can be bridged first to avoid the penetration of molten iron into the cracks and the further expansion of the cracks.
4. In the process of using the furnace, we should pay attention to observe the furnace condition. Observing the furnace condition is a kind of protection for intermediate frequency furnaces. Measure the furnace bottom every three days and observe the furnace wall every day, so as to ensure the safety of the furnace lining.
5. For the maintenance of electric furnace equipment, such as purging the coil frequently, cleaning the impurities on the coil to prevent coil breakdown, so as to avoid dismantling the furnace due to equipment failure, and effectively improve the service life of the crucible.
6. As the sintering layer of the new furnace is thin, the application process of the new furnace is very important. The first furnace with water from the new furnace should be melted by 50% charging, so as to avoid cracks and other defects caused by sudden cooling of furnace lining due to charging after all water comes out; the new furnace should be melted continuously as far as possible, so as to avoid cracks caused by intermittent melting, which should be melted continuously for one week in general; when the new furnace is used, the furnace bottom and furnace wall should not be impacted strongly, so as to avoid furnace lining spalling, cracks, etc. Therefore, in order to obtain a high furnace life, the early furnace using process should be done well.
7. High-temperature melting should be avoided as far as possible. At high temperatures, the furnace lining will react with molten iron in the crucible, as follows: SiO2 + 2C → Si + 2CO. The higher the temperature, the higher the C and the lower the Si, the more serious the corrosion of the furnace lining will be, especially in the new furnace. Therefore, the high temperature should be avoided as far as possible when the outlet water temperature is guaranteed. The outlet water temperature is 1490 ℃ ~ 1540 ℃, but it is generally controlled at 1490 ℃ ~ 1520 ℃ in the melting process. It is worth mentioning that after the water is discharged, the power is cut off to keep the temperature at a lower temperature. When the water is discharged, the temperature is raised according to the temperature of the last ladle, which can reduce the erosion of high-temperature molten iron on the furnace lining, prolong the service life of the induction furnace lining, and reduce the power consumption. It is a good method to improve furnace life and reduce power consumption.
8. Avoid overheating the lining. Because the heating rate of medium frequency furnaces are fast, when the smelter doesn’t pay attention to it, the burden will appear “bridging” phenomenon, and the local high temperature of the furnace lining will even exceed the fire resistance of the furnace lining, which may cause the induction furnace lining to melt and corrode; or when the foreman doesn’t pay attention to it, the furnace lining may also melt and corrode when the melting temperature is too high; this will greatly reduce the service life of the furnace lining, Attention must be paid at any time in the melting process. For example, the melting chemical industry should frequently poke materials, and the foreman should grasp the temperature of the hot metal at any time according to the color of the hot metal, so as to ensure the safety of the furnace lining.
