Tundish Outlet Modifier for Steel Flow Control

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Solution Overview

Problem

The continuous casting of steel faces issues with high residence time steel exiting refractory vessels leading to clogging and deposition of nonmetallic inclusions, primarily due to vortex formation and entrainment of slag, which results in decreased productivity and inclusion defects.

Innovation Solution

A refractory piece with a circumferential lip and internal fins is used to modify the liquid steel flow, preventing vortex tubes from reaching the outlet and introducing controlled turbulence to delay the deposition of nonmetallic inclusions, while mixing cold steel with hotter steel to homogenize temperature and prevent clogging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If steel is allowed to flow directly through the refractory vessel outlet, then productivity is maintained, but vortex formation entrains slag and causes clogging and inclusion defects

Engineering Contradiction:
Improvesteel casting rateVSAvoidflow stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

A refractory piece is introduced as an intermediary component between the steel flow and the outlet. This piece modifies the flow pattern by preventing vortex tubes from reaching the outlet, thereby eliminating slag entrainment while maintaining productive steel casting rates.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The refractory piece changes the flow parameters of the steel by introducing controlled turbulence and modifying velocity distribution. This prevents the formation of harmful vortexes while maintaining overall flow rate, thus resolving the contradiction between productivity and flow stability.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If cold steel accumulates at the bottom of the refractory vessel, then some steel is retained for temperature homogenization, but excessive cold steel causes clogging

Engineering Contradiction:
Improvesteel temperature homogeneityVSAvoidoutlet畅通性
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The refractory piece creates different flow conditions in different regions of the vessel. Cold steel at the bottom is subjected to controlled turbulence and mixing zones that promote gradual homogenization without causing excessive accumulation that would lead to clogging.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The controlled turbulence introduced by the refractory piece creates periodic mixing actions that continuously redistribute cold steel with hotter steel, maintaining temperature homogeneity while preventing stagnant accumulation that causes clogging.

Inventive Principle:
Principle #19Periodic action

3Manufacturing precision

If nonmetallic inclusions are allowed to deposit at the outlet, then inclusion defects occur in the steel, but preventing deposition requires controlled turbulence

Engineering Contradiction:
Improvesteel cleanlinessVSAvoidflow control structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The refractory piece serves as a mediator that introduces controlled turbulence to keep nonmetallic inclusions suspended in the steel flow rather than allowing them to deposit at the outlet, thereby maintaining steel cleanliness.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The refractory piece generates mechanical turbulence and flow disturbances that prevent the settlement and deposition of nonmetallic inclusions, keeping them suspended in the flowing steel and preventing inclusion defects.

Inventive Principle:
Principle #18Mechanical vibration

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 solution effectively reduces the deposition of nonmetallic inclusions and prevents clogging, ensuring a more homogeneous steel temperature and improved productivity by controlling the flow and mixing of steel within the refractory vessel.

Implementation Method 1

introduces controlled turbulence in the outlet to delay the deposition of nonmetallic inclusions

Methodology Applied
Scientific EffectTurbulence: Turbulence

Implementation Method 2

combine cold steel at the bottom of a refractory vessel, in a controlled matter, with steel in the body of the vessel to homogenize the temperature of steel exiting from the vessel

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3317034B1Tundish outlet modifier
Publication Date: 2020.04.15 VESUVIUS USA CORP
  • EP3317034B1 patent drawingFigure 1
  • EP3317034B1 patent drawingFigure 2
  • EP3317034B1 patent drawingFigure 3

AI summary

A refractory block configured to surround an outlet modifies, within a refractory vessel, the flow of molten metal passing through the outlet. The block takes the form of a base through which a main orifice passes, and a wall extending upwards around the periphery of the base. Structural features that may be included in the block include a circumferential lip around the exterior of the wall, an interior volume in which the radius decreases downwardly towards the main orifice in a plurality of steps, and flow openings in the wall that are configured to induce swirling in the flow pattern in the interior volume of the block.