Summarize and sort out several methods for judging the life of furnace lining:

1, when the lining life is approaching, pay attention to observe the electric furnace frequency meter, voltmeter, ammeter, etc. If the hands of these meters continue to swing under normal working conditions, the lining life will not continue to be used after the end of the work.

2, the circuit working sound obviously becomes "dull", the circuit shell and other grounding body contact the power supply will stop working, indicating that the iron liquid has broken down the furnace lining, should immediately cut off the power to pour the iron liquid inside the oven, stop continuing to use.

3. When the operator contacts the iron liquid with the iron bar and has electric shock, pay attention to the working sound of the electric furnace. If the sound is "dull" or even the sound changes obviously when the iron liquid is produced, it indicates that the iron liquid has invaded the lining or even broken down the lining, the iron liquid in the furnace should be treated according to the situation and no longer be used.

Here is a detailed introduction to some ways to extend life, in summary, is actually the following:

1, the erosion of the furnace bottom position

In the normal use of the lining, the thickness of the lining and the thickness of the bottom of the furnace will slowly thin due to the circulation of hot metal erosion in the long-term use, and the intuitive situation is the increase of the furnace capacity, the general lining will be eroded 30-50% of the time will be re-knocked off, and then a new furnace building work.

From the analysis of the entire furnace lining, where the erosion is obvious, it is in the slope position of the furnace bottom and the furnace lining. Generally, after long-term use of the furnace, the thicker lining material on the slope has been eroded to almost the furnace lining and the furnace lining on an arc surface, and even a slight depression appears in the square of the soil combined with the furnace bottom material and the furnace lining material. With the increase of the furnace age, the depression in this position It is also getting deeper and closer to the electric furnace coil, and affecting the use of safety, it is necessary to re-build the furnace. In addition to the quartz sand density at the time of furnace construction, the cause of furnace lining depression is also related to the chemical erosion when the feed is melted in our use and the mechanical erosion during operation.

2. Integrity of furnace lining

The integrity of the lining refers to the iron infiltration and cracks that often occur in the lining. In our production, there will often be a weekend rest furnace shutdown phenomenon, when the electric furnace empties and stops melting, the lining will slowly cool down, because the sintered lining material is a brittle material, the sintering layer will inevitably crack under the action of thermal expansion and cold contraction, and the crack is very harmful, which will lead to the infiltration of iron liquid into the lining and the furnace leakage phenomenon.

From the aspect of protecting the lining, the finer and denser the crack is and the distribution is uniform, because only in this way can the crack be closed in the cold furnace to a limited extent, and the lining has a complete sintering layer. In order to minimize crack propagation, we should pay attention to: avoid the lining sticking slag, the influence of too high temperature on the lining, the cooling of the lining, and the surface inspection of the lining often.