How to improve the service life of intermediate frequency furnace lining

1. Erosion of the furnace bottom position

existIntermediate frequency furnace liningIn normal use, the thickness of the furnace lining and the thickness of the furnace bottom will gradually become thinner due to the circulation erosion of molten iron in long-term use. The intuitive situation is the increase of furnace capacity. Generally, when the furnace lining is corroded by 30--50% It will be destroyed from the beginning, and then a new furnace building operation will be carried out. From the analysis of the entire furnace lining, the place with significant erosion is the slope position where the furnace bottom and the furnace lining are combined. Generally, the furnace is originally sloped after long-term use. The thicker furnace lining has been eroded to be similar to the furnace lining and is on an arc surface with the furnace lining, and even a slight depression appears in the soil where the furnace bottom material and the furnace lining are combined. The subsidence of the position is also getting deeper and deeper, and it is getting closer and closer to the electric furnace coil, which affects the safety of use, and requires re-construction of the furnace. The reasons for the depression of the furnace lining are not only due to the density of quartz sand during furnace construction, but also related to The chemical corrosion of the molten material in our use and the mechanical corrosion of the operation are related.

2. Integrity of the furnace lining

The integrity of the furnace lining refers to the iron infiltration and cracks that often appear in the furnace lining. In production, there are often weekend breaks and shutdowns. When the electric furnace is emptied and ends melting, the furnace lining will gradually cool down. It is a brittle material, so the sintered layer will inevitably show cracks under the effect of thermal expansion and cold contraction, and the cracks are very damaged, which will cause molten iron to enter the furnace lining and cause leakage. From the perspective of maintaining the furnace lining, the finer the cracks, the denser And the distribution is uniform, because only in this way can the cracks be bridged to the limit when the furnace is cold, and the furnace lining has a good sintering layer.

3. Cooling of furnace lining

When the furnace is shut down, we generally use the natural cooling of the furnace lining, but the cracks caused by natural cooling are obviously larger than those caused by the rapid cooling method of the intermediate frequency furnace lining. The rapid cooling method is the auxiliary cooling method. The air flow takes away the heat of the furnace lining in time, so that the surface of the furnace lining can be shortened in time to form many and small cracks, which can be better and timely bridged during the furnace start-up operation and reduce the probability of iron infiltration of the furnace lining. Pay attention to the uniformity of heat dissipation during rapid cooling. It is also necessary to avoid the moisture in the compressed gas, which can cause rapid cooling of the furnace lining, and cause partial peeling of the furnace lining.