Accident handling method of induction melting furnace

For the sudden accident of the induction melting furnace, it is necessary to deal with it calmly, calmly, and correctly to avoid the expansion of the accident and reduce the scope of influence. Therefore, it is necessary to be familiar with the possible accidents of induction furnaces and the correct handling of these accidents.

A. Induction melting furnace power outage and water outage The power outage of the induction furnace is caused by accidents such as overcurrent and grounding of the power supply network or the accident of the induction furnace itself. When the control circuit and the main circuit are connected to the same power source, the control circuit water pump also stops working. If the power outage can be recovered in a short period of time, and the power outage time does not exceed 10 min, then there is no need to use the backup water source, just wait for the power to continue. But at this time, preparations must be made for the standby water source to be put into operation. In case of a long power outage, the sensor can be immediately connected to a backup water source.

If the induction melting furnace is out of power for more than 10 minutes, the standby water source needs to be connected. Due to the power failure, the water supply to the coil is stopped, and the heat conducted from the molten iron is relatively large. If there is no water for a long time, the water in the coil may become steam, which will destroy the cooling of the coil, and the rubber tube connected to the coil and the insulation of the coil will be burnt out. Therefore, for long-term power outages, the sensor can switch to industrial water or start a gasoline engine to pump water. Because the furnace is in a power failure state, the water flow rate of the coil is 1/4-1/3 of that of energized smelting.

When the power outage time is less than 1h, cover the iron liquid level with charcoal to prevent heat dissipation, and wait for the power to continue. Generally speaking, no other measures are necessary, and the temperature drop of the molten iron is also limited. A 6t holding furnace, power outage for 1h, the temperature drops only 50 ℃.

If the power failure time is more than 1h, for small-capacity furnaces, the molten iron may solidify. It is best to switch the power supply of the hydraulic pump to a backup power supply when the molten iron is still fluid, or use a manual backup pump to pour out the molten iron. If the residual molten iron cannot be poured out temporarily in the crucible, add some ferrosilicon to lower the solidification temperature of the molten iron and delay its solidification speed. If the molten iron has begun to solidify, try to destroy the crust layer on the surface, punch a hole, and lead to the inside, so that the gas can be discharged when it is remelted, so as to prevent the thermal expansion of the gas from causing an explosion.

If the power failure time is more than 1h, the molten iron will completely solidify and the temperature will drop. Even if it is re-energized and melted, overcurrent will be generated, and it may not be energized. It is necessary to estimate and judge the power outage time as soon as possible, and the power outage is more than 1h, and the iron should be tapped as soon as possible before the melt temperature drops.

A power outage occurs during the period when the cold charge starts to melt, and the charge has not completely melted. You don’t need to turn the furnace, keep it in the original state, just continue to pass water, and wait for the next time the power is turned on to restart.

B. Induction melting furnace liquid iron leakage accidents in induction melting furnaces can easily cause equipment damage and even endanger personal safety. Therefore, it is necessary to maintain and maintain the furnace as much as possible to avoid liquid iron leakage accidents.

When the alarm bell of the alarm device rings, the power should be cut off immediately, and the surroundings of the furnace should be inspected to check whether the molten iron leaks. If there is any leakage, dump the furnace immediately and finish pouring the molten iron. If there is no leak, check and deal with it in accordance with the leaking furnace alarm inspection procedure. If it is confirmed that the molten iron leaks from the furnace lining and touches the electrode and causes an alarm, the molten iron must be poured, repair the furnace lining or rebuild the furnace. For unreasonable furnace building, baking, sintering methods, or improper selection of furnace lining materials, furnace leakage will occur in the first few furnaces of smelting. The molten iron is caused by the destruction of the furnace lining. The thinner the thickness of the furnace lining, the higher the electrical efficiency, the faster the melting speed, and the easier it is for molten iron to leak.

C. Induction melting furnace cooling water accident

1. Excessive cooling water temperature is generally caused by the following reasons: the sensor cooling water pipe is blocked by foreign matter, and the water flow is reduced. At this time, it is necessary to cut off the power, and use compressed air to blow the pipe to remove the foreign matter, but it is best not to stop the pump for more than 15 minutes ; Another reason is that the coil cooling water channel has scale. According to the cooling water quality, the coil water channel must be pickled with hydrochloric acid every 1 to 2 years, and the hose should be removed every six months to check the scale condition, such as on the water channel. There is obvious scale clogging, which needs to be pickled in advance.

2. The sensor water pipe suddenly leaks. The cause of water leakage is mostly caused by the insulation breakdown of the inductor to the magnetic shaft and the fixed support. When this accident occurs, immediately cut off the power, strengthen the insulation treatment at the breakdown, and seal the leaking surface with epoxy resin or other insulating glue to reduce the voltage for use. Melt the molten iron in the current furnace, and then process it after pouring it. If the coil channel is broken down in a large area, it is impossible to temporarily seal the leakage gap with epoxy resin, etc., so the furnace has to be shut down and the molten iron is poured for repair.