Continuous Casting Nozzle With Inclined Side Openings
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Solution Overview
Problem
Existing continuous casting technologies face challenges in effectively removing slag inclusions from molten steel, leading to reduced yield and operational issues such as nozzle damage and contamination of final products, while conventional methods fail to balance the flow dynamics to prevent slag inclusion and maintain high workability and surface quality.
Innovation Solution
A nozzle design with a bottom opening and inclined side openings, along with a dam structure, is used to control the flow dynamics, ensuring a balanced discharge angle and area to minimize slag inclusion and operational problems, while maintaining a stirred state for effective slag removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the recessed portion is formed in the bottom portion of the tundish to improve slag floatability, then the floatability of slag is improved, but the amount of molten steel remaining in the tundish increases, reducing yield
Solution Approach 1:
The nozzle discharge opening is segmented into multiple side openings distributed around the circumference, allowing controlled discharge that generates upward flow without requiring a large recessed portion in the tundish bottom
Solution Approach 2:
The discharge parameters are changed by controlling the number, area, and angular position of side openings, optimizing the upward flow velocity to enhance slag floatability while minimizing molten steel retention in the tundish
2Reliability
If the long nozzle is used to pour molten steel into the tundish to generate upward flow, then the upward flow is generated to allow slag to float, but the impact force damages or breaks the nozzle, causing operational problems
Solution Approach 1:
The single large discharge opening is divided into multiple smaller side openings, distributing the discharge flow and reducing the impact force on any single point of the nozzle structure
Solution Approach 2:
The side openings are positioned at specific angular locations on the nozzle circumference, creating localized discharge points that generate upward flow while avoiding concentration of impact force
3Reliability
If the upward discharge ports are formed to discharge molten steel upward to increase residence time, then the residence time is increased and slag floatation is facilitated, but the molten steel is stirred and mixed with slag, causing slag inclusion
Solution Approach 1:
The discharge angle parameter is optimized by positioning side openings at specific angles (30°-60° from horizontal), generating sufficient upward flow for slag floatation while avoiding excessive stirring that would cause slag inclusion
Solution Approach 2:
The discharge flow dynamics are controlled by adjusting the number and area of side openings, creating an optimal upward flow velocity that facilitates slag floatation without causing turbulent mixing
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The nozzle design reduces slag inclusion, enhances steel cleanliness, and prevents nozzle damage, thereby improving yield and product quality in continuous casting processes.
Implementation Method 1
to allow the slag to float so that it can be removed, weirs and dams are provided to form upward flows of the molten steel
Implementation Method 2
the upward flow of the molten steel is generated in a tundish to allow the slag to float upward in the tundish effectively
Implementation Method 3
the side opening is formed so as to be inclined downward at a predetermined angle with respect to a horizontal plane at 0°
Implementation Method 4
the impact force generated when the dropped molten steel impinges on the forward end may damage or break the long nozzle
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Provided is a nozzle for continuous casting configured to reduce slag inclusion, reduce the occurrence of operational problems, and reduce deterioration in the yield of the molten steel. Also provided are a continuous casting apparatus, a tundish, and a continuous casting method. A nozzle 1 for continuous casting that is used for pouring molten steel from a ladle into a tundish 2 includes: an immersion portion 3 that is to be immersed into the molten steel in the tundish 2; a bottom opening 5 formed in a forward end portion of the immersion portion 3, the forward end portion being located on a bottom side 4 of the tundish 2, the bottom opening 5 being configured to discharge the molten steel in a central axis direction of the immersion portion 3; and at least one side opening 6 formed on the side surface of the immersion portion 3. The side opening 6 is formed so as to be inclined downward at a predetermined angle with respect to a horizontal plane at 0°, and the total area S of the opening area of the bottom opening 5 and the opening area of the side opening 6 is 0.02 m2 or more and 0.15 m2 or less.