Conical Impact Pad Reduces Turbulence in Tundish Ladle Stream

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Solution Overview

Problem

High surface turbulence in continuous caster tundishes due to the incoming ladle stream of molten steel leads to chemical changes, inclusions, and reduced steel quality, as well as safety hazards from splashing, which conventional fluid flow control devices are insufficient to address.

Innovation Solution

A conical impact pad with a rotational symmetry and specific angle, combined with a diffuser and weir system, redirects the ladle stream to reduce turbulence, using refractory materials and erosion-resistant coatings to manage the flow and energy dissipation, creating a self-braking effect for laminar flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional flat impact pads or dams are used to control fluid flow, then some turbulence reduction is achieved, but they are insufficient to eliminate surface turbulence and open-eye formation

Engineering Contradiction:
Improvesurface turbulenceVSAvoidprotection against open-eye formation
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent applies a conical impact pad with a curved sloped surface instead of a flat impact surface. The conical shape with its curved geometry redirects the molten steel flow more effectively, reducing turbulence and preventing open-eye formation by creating a smoother flow pattern that follows the curved surface rather than reflecting off a flat surface.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent changes the geometric parameters of the impact pad by introducing a specific cone angle (α) between 10-30 degrees. This parameter change optimizes the flow redirection capability, allowing the molten steel to be redirected at an optimal angle that minimizes turbulence and surface disruption while maintaining effective flow control.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If the tundish floor is flat to simplify construction, then manufacturing is easier, but fluid flow reflection causes excessive turbulence and surface disruption

Engineering Contradiction:
Improvetundish floor constructionVSAvoidfluid flow turbulence
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The conical impact pad introduces curvature to the tundish floor at the impact zone, replacing the flat surface with a sloped conical surface. This curved geometry fundamentally changes the fluid flow behavior by redirecting it along the slope rather than causing reflection and turbulence, while still allowing the rest of the tundish floor to remain flat for ease of construction.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent applies the conical impact pad only at the specific location where molten steel impacts, rather than making the entire tundish floor curved. This localized application of curved geometry addresses the turbulence problem at the impact zone while maintaining flat floors elsewhere, balancing manufacturing simplicity with flow control effectiveness.

Inventive Principle:
Principle #3Local quality

3Strength

If conventional impact pads are used, then basic impact protection is provided, but they fail to create laminar flow and reduce turbulence effectively

Engineering Contradiction:
Improveimpact protectionVSAvoidflow pattern stability
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The conical shape with its curved surface provides both impact protection and flow stabilization. The curved surface absorbs and redirects the impact energy while simultaneously guiding the molten steel into a more stable, laminar flow pattern, achieving both impact protection and flow stability with a single geometric feature.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

By optimizing the cone angle parameter (α) within the range of 10-30 degrees, the patent achieves a balance between impact protection and flow stabilization. This parameter optimization ensures that the impact pad is sufficiently steep to protect against damage while not so steep that it causes flow reflection and turbulence, thereby achieving both impact strength and flow stability.

Inventive Principle:
Principle #35Parameter changes

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

Significantly reduces turbulence and 'open-eye' formation, improving steel quality by minimizing chemical changes and inclusions, and enhancing operational safety through reduced splashing and improved temperature homogeneity.

Implementation Method 1

A conical impact pad with a rotational symmetry and specific angle, combined with a diffuser and weir system, redirects the ladle stream to reduce turbulence

Methodology Applied
Scientific EffectFluid flow redirection:

Implementation Method 2

creating a self-braking effect for laminar flow

Methodology Applied
Scientific EffectImpact force: Impact Force

Implementation Method 3

Significantly reduces turbulence and 'open-eye' formation, improving steel quality

Methodology Applied
Scientific EffectTurbulence heating: Turbulence Heating

Data Source

PatentEP3194095B1Impact pad, tundish and apparatus including the impact pad, and method of using same
Publication Date: 2021.01.06 ARCELORMITTAL INVENSTIGACION Y DESARROLLO S L
  • EP3194095B1 patent drawingFigure 1~2
  • EP3194095B1 patent drawingFigure 3~4
  • EP3194095B1 patent drawingFigure 5

AI summary

A tundish impact pad, a tundish containing the same, and a method of using and assembly containing the impact pad and tundish are provided. The tundish impact pad features a base having a base surface with a conical impact surface area establishing an apex, a sidewall, and a top wall extending inwardly relative to the sidewall to terminate at an inner edge establishing a mouth opening spaced above and centered relative to the apex. The top wall includes a lip sloping radially inwardly and downwardly towards the conical impact surface.