Submerged Nozzle Flow Restrictors for Symmetric Steel Flow

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Solution Overview

Problem

Existing submerged nozzles in continuous steel casting experience biased flow patterns leading to asymmetrical flow in the mold, which results in reduced durability and premature failure due to uneven steel flow velocities and inclusion formation.

Innovation Solution

A submerged nozzle design featuring strategically positioned flow restrictors that restrict the passageway cross-section in specific directions while maintaining symmetry, centering the flow and reducing biased flow patterns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional submerged nozzles are used without flow restrictors, then the structure is simple and easy to manufacture, but biased flow patterns occur leading to reduced durability and premature failure

Engineering Contradiction:
ImprovedurabilityVSAvoidstructure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The passageway cross-section is segmented by flow restrictors that divide the flow into multiple paths, creating symmetrical flow patterns. The restrictors are positioned to segment the flow in specific directions while maintaining overall flow symmetry, preventing biased flow patterns that lead to premature failure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Flow restrictors are strategically positioned at specific locations within the passageway to address local flow asymmetry issues. The restrictors modify flow characteristics in specific regions without affecting the entire flow path, enabling targeted correction of biased flow patterns while maintaining simple overall structure.

Inventive Principle:
Principle #3Local quality

2Stability of the object's composition

If flow restrictors are added to center the flow and reduce asymmetry, then flow stability and symmetry are enhanced, but the device complexity increases

Engineering Contradiction:
Improveflow stabilityVSAvoidstructure
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

Flow restrictors are positioned upstream in the passageway to preliminarily center and symmetrize the flow before it reaches the outlet ports. This preliminary action ensures that flow asymmetry is corrected early in the flow path, maintaining stable and symmetrical flow patterns throughout the remaining passageway length.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The flow restrictors modify flow parameters such as velocity distribution and flow direction by restricting the passageway cross-section in specific directions. This changes the flow characteristics to achieve symmetry and stability without requiring complex active control systems.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If flow restrictors restrict the passageway cross-section in specific directions, then biased flow is reduced and flow symmetry is improved, but the passageway cross-section is reduced

Engineering Contradiction:
Improveflow symmetryVSAvoidpassageway cross-section
Core Design Contradiction:
Stability of the object's compositionVSArea of moving object

Solution Approach 1:

Flow restrictors are designed to restrict the passageway cross-section only in specific directions where flow asymmetry occurs, rather than uniformly reducing the cross-section in all directions. This selective restriction maintains flow symmetry while minimizing the overall reduction in passageway area and steel flow capacity.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4691665A1Submerged nozzle
Publication Date: 2026.02.11 REFRACTORY INTELLECTUAL PROPERTY GMBH & CO KG
  • EP4691665A1 patent drawingFigure 1~2
  • EP4691665A1 patent drawingFigure 3~11
  • EP4691665A1 patent drawingFigure 12~13

AI summary

Submerged nozzle (1) through which molten steel can be poured from a tundish into a mold, the submerged nozzle (1) comprising: a substantially tubular body (2), extending from a first end (3) to a second end (4); a passageway (5), extending through the tubular body (2) along a longitudinal axis (A) from the first end (3) towards the second end (4), the passageway (5) being defined by an inner wall (2i) of the tubular body (2), the passageway (5) having a passageway cross section (5a) normal to the longitudinal axis (A); at least one inlet port (6), opening into the passageway (5) at the first end (3); at least one pair of opposing outlet ports (8), opening into the passageway (5) in a region (7) adjacent to the second end (4), each outlet port (8) comprises an outlet port center (8a); an outlet port axis (8b) being defined as the connection between the outlet port centers (8a) of each opposing outlet port (8) of at least one pair of opposing outlet ports (8), wherein at least one pair of opposing outlet ports (8) are arranged such that the outlet port axis (8b) is orthogonal to the longitudinal axis (A); a transverse outlet port axis (8c) being defined as orthogonal to the outlet port axis (8b) and orthogonal to the longitudinal axis (A); and at least one first flow restrictor (10), preferably the at least one first flow restrictor (10) is a pair of opposing flow restrictors (10), the at least one first flow restrictor (10) protruding from the inner wall (2i) of the tubular body (2) into the passageway (5); wherein the at least one first flow restrictor (10) is positioned closer to the first end (3) than to the second end (4); wherein the at least one first flow restrictor (10) restricts the passageway cross-section (5a) at least in a direction of the transverse outlet port axis (8c) from the longitudinal axis (A) within the passageway cross-section (5a); and wherein the at least one first flow restrictor (10) does not restrict the passageway cross-section (5a) in any direction of the outlet port axis (8b) from the longitudinal axis (A) within the passageway cross-section (5a).