Precautions during the construction of tundish linings

The intermediate vessel is a key piece of equipment in continuous casting production. The construction quality, especially the construction quality of the dry material working layer of the intermediate vessel, will directly affect the cleanliness of the molten steel, the quality of the cast billet, and the safety of production.

Correct lining construction methods. First, the following points should be noted for the construction of the dry material working layer:

First, zonal construction. The bottom working layer should be constructed first, followed by the placement of the working layer tundish mold, and then the wall working layer and slag line working layer. The bottom working layer usually has a thickness of about 100mm. It should be noted that it should be evenly spread and leveled. When placing the working layer tundish, the position should be found to ensure that it is placed flat and upright, and the distance between the two sides and the permanent layer should be kept consistent. When pouring the wall dry material and slag line dry material, the required height should be reached according to the design requirements, leveled and compacted. Avoid adding too much material at one time, which may cause the bottom to vibrate and not be compacted. The vibration time should be set according to different materials.

Second, baking of the working layer. The corresponding baking time should be set according to different materials, types of gas used, etc. If the gas baking efficiency is low, the baking time should be appropriately extended.

Third, demolding and curing. The demolding time should be determined according to the type of binder and weather conditions (the demolding time will be shorter in winter when the temperature is low). When demolding, avoid damaging the working layer of the tundish. After demolding, the surface of the lining should be free of cracks and peeling, and the color should be uniform.

Fourth, prefabricated component installation. The prefabricated components should be dry and clean. Before installation, apply refractory slurry (such as magnesia slurry) to the contact surface to ensure that the joint width is ≤2mm, and fix it with wooden wedges or steel clips to prevent displacement.

Secondly, attention should be paid to the treatment of key parts. First, the nozzle area. The area around the upper nozzle should be filled with dry material to ensure that it is tightly combined with the wall; after the lower nozzle is installed, the sealing should be checked. The kerosene penetration method can be used to detect whether there is leakage. Second, the transition between the bottom and the wall. It should be made into an arc shape (R≥50mm) to avoid the formation of right angles, which can cause stress concentration and lead to lining peeling. Third, construction environment control. Fourth, dust prevention and ventilation. Dust is generated during tamping or mixing, so dust masks should be worn, and the construction area should be well ventilated to prevent the accumulation of harmful gases.

  Carefully and cautiously, safety measures must be in place.

In the construction of the dry material working layer of the intermediate vessel, safety must be prioritized! First of all, personal protection should be emphasized. Construction personnel should wear high-temperature resistant gloves, dust masks, and goggles. During baking, stay away from the tundish to avoid burns.

Secondly, attention should be paid to equipment safety. Electrical equipment such as vibrators should be grounded to prevent electric shock; during baking, check the sealing of the gas pipeline to prevent leakage and explosion.

Third, there should be emergency handling measures. If any abnormalities such as tundish deformation or lining cracking are found during construction, work should be stopped immediately, the cause should be analyzed and corrected before continuing.

In summary, the construction of the intermediate vessel working layer should follow the principle of "zonal material selection, layered control, and key reinforcement". Through standardized operation and refined management, the service life of the intermediate vessel can be effectively improved, and the stability and quality of continuous casting production and cast billets can be guaranteed. In actual operation, it is necessary to flexibly adjust the specific process parameters of the steel plant (such as steel grade and casting speed) and continuously optimize the construction scheme.