What are the safety protection measures for medium frequency induction furnaces
- Hydraulic system
The hydraulic system of the medium frequency coreless induction furnace is used to pour molten metal out of the furnace, and to open and close the furnace lid. In order to ensure reliable work, the hydraulic station of the electric furnace should be equipped with two main pumps of the same specification (one for use and one for backup). The inlet end of the tilting furnace hydraulic cylinder needs to be equipped with a throttle valve to prevent the furnace body from falling suddenly due to the loss of pressure in the hydraulic system. When the power supply is interrupted for a long time, the molten metal in the electric furnace may cool and solidify. This situation may damage the furnace lining. It is very dangerous to melt the solidified metal in the furnace by operating the electric furnace. Therefore, the electric furnace The hydraulic system should be equipped with an emergency system. When the power supply of the power grid is interrupted, if necessary, this emergency system can be used to pour out the molten metal in the furnace to avoid solidification in the furnace.
- Earth leakage furnace monitoring and alarm
In the operation of the coreless medium frequency induction furnace, if the furnace lining is damaged, it will cause a furnace leakage accident. If the molten metal leaks from the furnace lining, it will damage the insulation of the induction coil, the coil support and the yoke. If it is not found in time, it will cause serious leakage. If the molten metal burns out the copper tube of the coil, the water in the tube and the molten metal may cause an explosion and cause a serious accident. It can be seen that it is absolutely necessary to set up an alarm system for furnace lining leakage. A DC circuit can be connected in parallel to the AC power supply loop of the induction coil. The molten metal in the furnace is grounded through the furnace bottom electrode, and the induction coil is connected in series with the DC power supply and the milliampere meter and grounded, so the molten metal, the furnace lining, the coil and the milliampere meter are connected into a DC loop. When the furnace lining is in good condition, because the resistance of the furnace lining is large, the mA meter shows a small value; if the furnace lining is in poor condition and molten metal penetrates into the furnace lining close to the induction coil, the resistance of the furnace lining will decrease, and the milliampere resistance will decrease. The indicated value of the table becomes larger. When the current value exceeds the set value, an alarm will be issued and the main power supply will be cut off, thus preventing the occurrence of furnace leakage accidents.
- Automatic fault diagnosis
Modern induction furnaces are equipped with a computer management system. This system has automatic fault diagnosis function. The system scans the set points of the equipment, and when the parameters of the set points are found to be abnormal, an alarm will be issued and the fault information can be displayed and recorded. Because the scanning speed is very fast, reaching hundreds of times per minute, the fault will be found in its initial state, so that the fault will not cause serious equipment damage. The relevant information about the failure will be stored in the computer for future reference.
In addition to the above, there are other safety measures. For example, when the cabinet door of the medium frequency power supply is opened, the incoming power supply will be automatically cut off by a mechanical interlock; another example is that each capacitor is equipped with a pressure switch. When the pressure exceeds the set value, it will alarm and cut off the power supply to prevent the capacitor from exploding due to excessive internal pressure.
