Why Can't the Tundish Nozzles Open Automatically?

The tundish nozzle is a critical component in the continuous steel casting process. Molten steel flows through the tundish and passes the nozzle, and only nozzles with high resistance to heat and corrosion can perform effectively during casting. Therefore, strict requirements are imposed on the material of tundish nozzles.

At the start of casting, self-opening of the tundish nozzle is crucial. Production experience shows that nozzles with good self-opening maintain more stable casting speed, allow for longer casting duration, and ensure higher billet quality.

01

Blockage by solidified steel

After the ladle opens, molten steel enters the tundish. As the tundish absorbs heat, the steel temperature decreases, and low-temperature steel solidifies within the nozzle, causing blockage. To prevent this, in addition to maintaining a reasonable steel tapping temperature, the height of the steel-retaining ring above the nozzle should also be appropriately increased.

02

Blockage by slag adhesion

To reduce heat loss and maintain preheating temperature, tundishes are covered with lids containing preheating holes. After long use, these lids often accumulate residual steel and slag. During preheating, these residues may melt and, under the suction of exhaust devices, flow into the nozzle, blocking it. Some blockages can be cleared, while others remain lodged in the nozzle, preventing self-opening.

 

 

1. It is essential to strictly control the quality of tundish lining and preparation, ensuring the cleanliness of the tundish interior and cover. This creates favorable conditions for smooth nozzle opening, improves molten steel purity, and reduces external inclusions.
2. Since the tundish nozzle plays such an important role in the continuous casting process, technicians often optimize the casting operation. For example, the quick-change technique for fixed nozzles was developed to improve nozzle utilization.
3. There are many types of tundish nozzles. Depending on casting requirements, their shapes and materials vary significantly. Selecting the right nozzle is key to optimizing the continuous casting process.

Anyang Changtai Silicon Industry Co., Ltd. is a comprehensive manufacturer specializing in the design, processing, and sales of zirconia high-temperature products. If you require zirconia high-temperature products, please email us at: zhang@ayctgy.com. We will respond to your inquiry promptly upon receipt.

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