The position of the lining of the intermediate frequency furnace is between the induction ring and the melted metal, which plays a barrier role, and can improve the working efficiency of the intermediate frequency furnace. The furnace lining has a great influence on the medium frequency furnace, which will not only affect the service life of the medium frequency furnace, but also affect the safety problems during the use of the medium frequency furnace. Therefore, it is necessary to pay special attention to it and deal with problems in time. The following small edition of Anaijie will introduce the scrap standard of intermediate frequency furnace lining and the method of replacing the lining.

1. Scrap standard for intermediate frequency furnace lining

1. Thickness of furnace bottom

If the inspection finds that the bottom of the intermediate frequency furnace has serious wear, can not be repaired and there is leakage, at this time it may have broken down the lining, should immediately stop the operation of the equipment and replace the lining.

2. Thickness of furnace wall

If the wall thickness of the intermediate frequency furnace is checked, it is found that when the wall thickness of the intermediate frequency furnace is less than one-third of its initial thickness, the furnace lining should be replaced again, and the equipment can operate normally. The reason is that if the furnace wall is too thin, the mutual inductance between the induction coil and the smelting workpiece increases, the leakage inductance decreases, and the DC equivalent resistance decreases. When starting, the current is large, the current is low, and the inverter commutation is difficult, resulting in the difficulty of starting the medium frequency power supply.

3. Data indication

According to the past experience to calculate the service life of the current lining, when the lining life is approaching, more observation of the electric furnace frequency meter, voltmeter, ammeter, etc., if the dial is constantly swinging under normal working conditions, then the lining needs to be replaced after the end of the work.

4. Sound judgment

During the operation of the medium frequency furnace, if there is electric shock when the worker uses the iron bar to contact the metal liquid normally, then it is necessary to carefully observe the working sound of the electric furnace, if the sound is "dull", and the sound change is more obvious when the metal liquid is produced, which indicates that the metal liquid has eroded the lining or even broken down the lining. At this time, the metal liquid in the furnace needs to be treated according to the situation. Do not use the current lining.

Second, the method of replacing the lining of the intermediate frequency furnace

1. First stop the operation of the intermediate frequency furnace, and then start to replace the lining after the furnace body with the intermediate frequency furnace is cooled.

2. Remove the existing lining in the intermediate frequency furnace, pay attention to cleaning thoroughly, and then re-build the lining with refractory materials.

3, when re-laying the furnace lining, it is necessary to pay attention to the bottom layer can be laid with multiple layers of prefabricated firebricks as the bottom floor.

4, after the completion of the furnace lining knot, the surface of the Φ4-Φ5mm porosity, with a small fire to bake the pouring mouth in advance.

5, the replacement time of the furnace lining should be controlled within 30 hours, the time of relaying the furnace lining should not exceed 492 hours, theoretically speaking, generally not more than 21 days, because the long-term shutdown of the furnace is not conducive to the performance of the medium-frequency induction furnace.

The above is the relevant introduction of Anaejie small series on the scrap standard of intermediate frequency furnace lining and the method of replacing the lining. The scrap of intermediate frequency furnace lining can be judged from the thickness of the furnace bottom, the thickness of the furnace wall, the data indication and the sound. If you find anomalies in the use process, the lining should be replaced in time.