Maintenance of water cooling cable of medium frequency smelting furnace
The water cooling cable of the medium frequency smelting furnace uses the water cooling cable to solve the large current transmission of the smelting furnace. It is installed between the capacitor bank and the induction coil to ensure the normal transmission of the frequency conversion current and make the medium frequency smelting furnace operate normally. If there is a problem with the water cooling cable of the smelting furnace, the following faults will occur
1. Because the water-cooling cable of the medium frequency smelting furnace is connected with the induction coil of the medium frequency smelting furnace, it is a part of the load circuit of the smelting furnace. Because the medium frequency smelting furnace has to tilt the furnace every other hour, it will drive the water-cooling cable to move. Therefore, the water-cooling cable is subject to tension and torsion, and tilts with the furnace body, resulting in twists and turns and fatigue fracture. During the breaking process of water-cooled cables, most of them are broken first, and then the small part that is not broken is burned out quickly during high-power operation. At this time, the medium frequency power supply will produce high overvoltage. If the overvoltage protection is not reliable, the thyristor will be burned out. After the water cooling cable is disconnected, the medium frequency power supply cannot be started.
Since the water-cooled cable has the risk of fracture, it is necessary to regularly check whether the water-cooled cable has the precursor of fracture. Disconnect the water-cooled cable from the output copper bar of the electric heating capacitor, and measure the resistance value of the cable with the resistance block (200 Ω block) of the multimeter. The resistance value is zero under normal conditions and infinity under disconnection. When measuring with a multimeter, turn the furnace body to the dumping position to drop the water-cooling cable, so as to completely separate the broken part, so as to correctly judge whether the core is broken.
2. The leakage of water cooling cable of medium frequency smelting furnace is easy to distinguish. You can observe whether there are water seepage marks on the contact surface of the water-cooled cable nozzle, and whether there are cracks on the water-cooled cable hose of the medium frequency smelting furnace, or the hose is burned due to induction heating caused by metal objects such as iron filings touching the hose. If there are damage marks, replace the hose immediately.
3. Whether the connection of the water-cooling cable of the medium frequency smelting furnace is loose, especially the connecting bolts, must be tightened. Do not loose, which will cause virtual connection, which will cause damage to the thyristor of the medium frequency power supply.
4. Check whether the water circuit of water cooling cable of medium frequency smelting furnace is smooth to ensure normal circulating cooling. Due to the frequent blockage of water channel, the cooling effect is reduced, which makes the temperature of water-cooling cable of medium frequency smelting furnace rise and burn the cable. When checking the water-cooling cable of medium frequency smelting furnace, observe the flow of the water path, and you can’t judge that the water path cooling is normal only by the high water pressure of the cooling water path.
