What reasons will affect the service life of the intermediate frequency furnace lining?

The lining of the induction furnace (ie the crucible) is an important working part of the power frequency induction furnace. It isolates the high-temperature molten iron from the inductor of the furnace and accepts the high temperature effect during the smelting process (greater than or equal to 1500 degrees Celsius). Because the furnace lining is in the In the process of use, it is often subjected to severe impact and bumping of the charge during feeding. The electromagnetic stirring effect during smelting will cause the molten metal to violently scour the furnace lining, and the chemical erosion of the furnace lining by the slag and continuous operation will cause the temperature of the furnace lining to be rapidly cooled and heated. Changes, etc., are more damaging to the furnace lining, resulting in cracks, corrosion, peeling, etc. of the furnace lining.

1. Reasons affecting the service life of the intermediate frequency furnace lining

The service life of the furnace lining should start from the quality standards and safety operation rules of the refractory material. Several issues affecting the service life of the furnace lining are discussed below.

(1) There are insulation layers, insulation layers, alarms, etc. between the furnace lining and the inductor (coil), and the lap joint should be flat and tight when laying. Lay asbestos board, asbestos cloth and other insulation layers inside the alarm , It has the ability to resist the penetration of molten iron. The mica sheet and glass fiber cloth are the insulating layers, and the alarm device is made of stainless steel plate. It is laid between the insulating layer and the insulating layer to supervise the working status of the furnace. In case of molten iron leakage, the alarm will automatically alarm to protect the safe operation of the furnace lining.

(2) The selection of refractory materials should have good integrity of the furnace lining, high refractoriness, simple molding, and easy sintering and dismantling. For this reason, our factory selected an acid furnace lining material with an appropriate amount of B'o added in SiO as a binder. .Because SiO can be sintered at lower temperatures, the polycrystalline transformation of SiO is very slow, and it is always dimensional during use.

It maintains the expansion performance, which is very beneficial to maintain the integrity of the furnace lining and promote the densification of the furnace lining, and my country is rich in silica sand resources.

(3) The quality of silica sand The main component of silica sand is SiO, generally si.amp;gt;99.5 percent, F f1amp;lt;0.05 percent, H oamp;lt;0.5 percent refined quartz sand. The amount of boric acid added It depends on the different parts of the furnace (see Figure 1). Silica sand is the refractory material for the furnace lining. Coarse and large-grained silica sand has better corrosion resistance to molten iron, but poor mechanical impact resistance after sintering. When the furnace is running, the energization should be stopped, and the charge should be taken out and then re-feeding and energizing. These precautions are to avoid local excessive heating in the furnace and the resulting excessive burning of the furnace lining material.