Casting Nozzle Bore Design for Stable Molten Metal Flow

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Solution Overview

Problem

Refractory pour tubes for casting operations face issues with turbulence, slag entrainment, nonuniform flow patterns, and unstable discharge jets, leading to flow asymmetry and vortexing, which affect the quality of the casting process.

Innovation Solution

A refractory pour tube design with a bore configuration featuring multiple cross-sectional area reductions, a flow divider, and baffles positioned between the flow divider and side walls to stabilize the flow and direct it towards the sides, reducing turbulence and enhancing flow distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional pour tube design is used, then the structure is simple, but turbulence and flow asymmetry occur leading to poor discharge stability

Engineering Contradiction:
Improvedischarge stabilityVSAvoidbore configuration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The bore is divided into multiple distinct sections (contraction section, expansion section, adjustment section) with specific geometric features in each. This segmentation allows each section to perform a specific function in controlling the flow, transforming the single-phase flow into a multi-stage controlled process that reduces turbulence and achieves stable discharge.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the bore have different geometric properties tailored to specific local requirements. The contraction section has decreasing cross-sectional area to accelerate flow, the expansion section has increasing area to reduce velocity, and the adjustment section has optimized geometry for flow distribution. This local optimization of geometric quality ensures stable discharge while managing complexity through functional zoning.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If the pour tube has a simple bore configuration, then manufacturing is easier, but flow uniformity and turbulence control are poor

Engineering Contradiction:
Improveflow pattern uniformityVSAvoidbore fabrication difficulty
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The bore geometry is designed to pre-condition the flow before it reaches the discharge point. The contraction section pre-accelerates the flow, the expansion section pre-reduces velocity and turbulence, and the adjustment section pre-distributes the flow uniformly. These preliminary actions within the bore ensure that by the time metal exits, the flow is already optimized, achieving high manufacturing precision in flow control.

Inventive Principle:
Principle #10Preliminary action

3Object-affected harmful factors

If conventional nozzle geometry is used, then the structure is straightforward, but slag entrainment occurs reducing metal quality

Engineering Contradiction:
Improveslag entrainmentVSAvoidbore geometric complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The design transforms the potentially harmful turbulent flow and high velocity into beneficial controlled flow patterns. The contraction section converts pressure energy into kinetic energy, the expansion section converts kinetic energy back into pressure energy while reducing turbulence, and the adjustment section ensures uniform distribution. This conversion process transforms what would be harmful turbulence into beneficial controlled flow that prevents slag entrainment.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 design achieves a stable and uniform flow pattern with reduced turbulence, improving the distribution of molten metal and preventing slag entrainment, resulting in a more consistent and high-quality casting process.

Implementation Method 1

a contraction section, adjacent to the entry section, in which the cross-sectional area of the bore decreases from the upper end to the lower end of the contraction section

Methodology Applied
Scientific EffectFluid acceleration through contraction: Venturi Effect

Implementation Method 2

an expansion section, adjacent to the contraction section, in which the cross-sectional area of the bore increases from the upper end to the lower end of the expansion section

Methodology Applied
Scientific EffectFluid deceleration through expansion: Diffusion

Implementation Method 3

a flow divider and baffles positioned between the flow divider and side walls to stabilize the flow and direct it towards the sides

Methodology Applied
Scientific EffectFlow redirection through geometric constraints: Geometry

Data Source

PatentEP3972754B1Casting nozzle
Publication Date: 2024.02.07 VESUVIUS GROUP SA
  • EP3972754B1 patent drawingFigure 1
  • EP3972754B1 patent drawingFigure 2
  • EP3972754B1 patent drawingFigure 3~5

AI summary

A casting nozzle (10) for use in the casting of molten metal produces a stable flow pattern having an elongated section in the horizontal plane. The bore (12) cross-sectional area contains, from entry (24) to exit (26, 28), at least two significant section area reductions to reduce turbulence, realign streamlines and affect flow distribution inside the nozzle. The bore cross-section has a local minimum value in a contraction section (40) located between the entry section (30) and an expansion section (50). Bore cross-sectional area decreases from the expansion section to the lower end of the nozzle. The two significant cross-sectional area reductions cooperate with other structures within the bore to stabilize flow.