During the use of the medium frequency furnace, sometimes the electric furnace inductor will ignite between turns and leak water. The traditional treatment method is to dump the furnace, wait for the crucible to cool, remove the inductor, repair it with oxygen welding, and then reinstall it before building the furnace. The average furnace life of electric furnace crucible is greatly reduced. After practical exploration, a set of effective methods are summarized, which can deal with such faults efficiently and conveniently. The specific operations are as follows:
I. material preparation and requirements:
① High strength AB adhesive is required to be temperature resistant at 120 ℃ and 25 ℃ for 5 ~ 10 minutes, and reach the maximum strength in 24 hours.
② 1755 surfactant is used to clean the surface of the leakage part of the sensor, in order to make the strong glue plugging more reliable. If not, it can not be used.
③ For electrical bakelite, the thickness is required to be 1 ~ 1.5mm thicker than the turn to turn thickness of the inductor
④ Compressed air shall be available at the operation site. If not, soot blower can also be used.
⑤ Prepare a wooden wedge to expand the distance between the water leakage between the turns of the inductor by 2 ~ 3mm.
II. Repair operation:
① First, confirm the specific location of the inter turn water leakage, transfer the molten iron in the furnace to the standby furnace to continue smelting, reduce the cooling flow to about 1 / 5 of the normal flow by the damaged inductor, and continue cooling with water for 1 ~ 2 hours. If there is no standby furnace, maintain normal cooling for 2 ~ 3 hours and start repair.
② Confirm the size of the loophole (if the maximum diameter of the loophole exceeds 2cm, it is better to remove the sensor, and I have not made up the loophole exceeding 2cm), and confirm whether the upper and lower parts are broken down.
③ The electrical bakelite is sawn into blocks according to the width of the inductor, the length is 1 ~ 2cm longer than the maximum diameter of the loophole, and the thickness is basically the same as that of the inductor after wedging.
④ After the sensor is cooled for 1 ~ 2 hours, remove the inlet and outlet of the sensor and blow air into the sensor until there is no steam at the leak.
⑤ Use 1755 surfactant to treat the water leakage, prepare the strong AB glue in the ratio of 1:1, stop the air blowing of the inductor, apply the AB glue to the water leakage, the thickness is accumulated for 1 ~ 2mm, the area ratio of the outer diameter of the loophole exceeds 1 ~ 2cm, and apply ab glue on the upper and lower parts of the turns.
⑥ Apply AB glue evenly on both sides of the electrical bakelite approved in advance, with a thickness of about 1 ~ 2mm. Insert it into the water leakage, quickly remove the wooden wedge, and let the bakelite naturally compress between the turns of the inductor. It is best if there is AB glue overflow around.
⑦ Wait for 5 ~ 10 minutes (depending on the sensor temperature and curing waiting time), observe that the AB glue on the rubber mixing plate turns white and hard, and then conduct water pressure test. Power on and start the furnace without leakage.
① During repair, the temperature of the sensor shall not be too high, and water shall not be used in the sensor, otherwise bubbles will be generated, resulting in repair failure.
② Novices suggest that the fully cooled inductor be used for experiment first, and the reheater can be repaired after being proficient.
③ Water seepage often occurs during repair, and the leakage shall be repaired after re cleaning. Be patient. I have repaired the same place three times before I succeed.
④ The repaired inductor shall not be short of water during smelting, otherwise the AB glue will fall off due to high temperature failure, resulting in water leakage again.
⑤ The temperature resistance of strong AB adhesive must reach 120 ℃, and the low temperature resistance will affect the thermal repair effect.