The ladle nozzle (also known as the ladle slide gate or pouring gate) is an important flow control device at the bottom of the ladle (the container that holds molten steel) during the steelmaking process. Its main function is to precisely control the flow of molten steel from the ladle to the tundish or mould.
1. Molten Steel Flow Control
The opening and closing of the nozzle is adjusted via a sliding mechanism (slide plate) to precisely control the flow of molten steel and ensure a stable pouring process.
This prevents the steel from flowing out too quickly or too slowly, which would affect the quality of the continuous casting billet or the production efficiency.
2. Preventing Secondary Oxidation Of The Steel
The nozzle is usually made of high-temperature-resistant materials (such as aluminous carbonaceous or zirconium materials) to reduce the contact between the molten steel and air and prevent the formation of oxidized inclusions.
Some nozzles are designed as long nozzles or immersion nozzles to further isolate the air.
3. Non-Metallic Inclusion Filtration
Some nozzles have built-in filters or porous structures that can intercept impurities in the molten steel (such as deoxidization products and slag particles), improving the purity of the molten steel.
4. Protect The Pouring System
During continuous casting, the sealing design between the nozzle and the tundish prevents molten steel from splashing or sucking in, protecting the equipment and reducing safety risks.
Immersion nozzles also reduce the impact of molten steel on the protective slag in the mold.
5. Rapidly Shut Off The Steel Flow
In an emergency (e.g. steel leakage, equipment failure), the sliding mechanism can quickly close the nozzle to stop the flow of molten steel and prevent the accident from worsening.
6. Adapt To Multi-Furnace Continuous Casting
Continuous casting of molten steel from multiple furnaces can be achieved by replacing or adjusting the nozzle, improving production efficiency.
