Casting Nozzle Protrusions for Molten Steel Flow Control
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Solution Overview
Problem
Existing casting nozzles face issues with molten steel drift and alumina deposition, leading to uneven flow rates and reduced casting quality, which are not adequately addressed by conventional methods such as shape modifications and inert gas spraying.
Innovation Solution
A casting nozzle design featuring independent protrusion portions and/or concave portions with specific size and placement criteria to generate turbulent flow, preventing stagnation and alumina deposition, ensuring uniform flow and extended nozzle life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the aperture of the hole-including plate is reduced to control flow rate, then the flow rate of molten steel is reduced, but a drift occurs in the immersion nozzle causing ununiform flow rate distribution
Solution Approach 1:
The patent applies local quality by providing protrusions at specific locations within the nozzle hole where drift is most likely to occur. These localized structural modifications create turbulence only in critical regions without affecting the overall flow rate control, thereby maintaining uniform flow distribution while allowing aperture reduction for productivity control.
Solution Approach 2:
The patent segments the nozzle hole by dividing it into multiple regions with protrusions placed at different positions along the flow path. This segmentation allows different sections to serve different functions: some regions control flow rate while others prevent drift, resolving the contradiction between productivity and manufacturing precision.
2Manufacturing precision
If conventional shape modifications are made to prevent drift, then flow uniformity is improved, but alumina deposition still occurs on the inner pipe surface
Solution Approach 1:
The patent addresses alumina deposition by providing protrusions at specific locations where deposition is most likely to occur. These localized protrusions create turbulence that prevents alumina from adhering to the inner pipe surface, while maintaining the overall nozzle shape and flow distribution characteristics.
Solution Approach 2:
The patent converts the harmful effect of turbulence (which can cause erosion and deposition) into a beneficial effect by strategically placing protrusions to generate controlled turbulence. This turbulence prevents alumina deposition by keeping particles suspended in the flow, thereby converting what would normally be a harmful phenomenon into a protective mechanism.
3Object-generated harmful factors
If inert gas spraying is used to prevent alumina deposition, then deposition is reduced, but the complexity of the system increases
Solution Approach 1:
The patent applies self-service by designing the nozzle structure itself to prevent alumina deposition through integrated protrusions. The nozzle structure provides its own protection against deposition through turbulence generation, eliminating the need for external inert gas spraying systems and reducing overall system complexity.
Solution Approach 2:
The patent extracts the alumina deposition prevention function from the external inert gas spraying system and integrates it directly into the nozzle structure through protrusions. This extraction simplifies the system by removing the need for complex gas delivery systems while maintaining the deposition prevention effect.
4Productivity
If the nozzle inner hole is narrowed due to alumina deposition, then casting speed is reduced, but the nozzle structure remains simple
Solution Approach 1:
The patent applies preliminary action by providing protrusions in advance within the nozzle structure before alumina deposition can occur. These pre-positioned protrusions create turbulence that prevents alumina from adhering to the inner surface, thereby maintaining the original nozzle dimensions and casting speed without requiring complex active control systems.
Solution Approach 2:
The patent provides beforehand cushioning against alumina deposition by incorporating protrusions that create protective turbulence. This preliminary protection prevents the narrowing of the nozzle inner hole that would otherwise occur due to deposition, maintaining casting speed without adding complex monitoring or adjustment systems.
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 effectively prevents molten steel drift and alumina deposition, ensuring consistent flow rates and high-quality steel casting by generating turbulent flow and maintaining nozzle integrity.
Implementation Method 1
a plurality of independent protrusion portions and/or concave portions discontinuous in both directions parallel and perpendicular to a molten steel flowing direction are disposed in a molten steel flow hole portion... each of the protrusion portions and/or concave portions has a size satisfying specific expressions... generate turbulent flow
Data Source
AI summary
An object of the invention is to provide a casting nozzle in which attachment and deposition of alumina or the like can be prevented while a drift of molten steel can be prevented.The casting nozzle according to the invention is characterized in that the casting nozzle has a molten steel flow hole portion in which “a plurality of independent protrusion portions and/or concave portions” are disposed so that each of the protrusion portions and/or concave portions has a size satisfying the expression (1): H≧2 mm and the expression (2): L>2×H mm [in which “H” shows the maximum height of the protrusion portion or the maximum depth of the concave portion, and “L” shows the maximum length of a base portion of the protrusion portion or concave portion].