Ladle Teeming Control to Inhibit Molten Steel Vortex Formation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In continuous casting production, excessive steel slag entrapment at the ladle teeming phase leads to waste of clean molten steel and inefficiencies due to vortex suction, with existing methods failing to effectively inhibit slag entrapment and reduce residual steel.

Innovation Solution

A control method and apparatus that analyze vortex formation processes, employing different optimization strategies to inhibit or destroy vortices, using a ladle weight detector, molten steel flow field distribution detector, electromagnetic brake, steel slag detector, and slide gate nozzle controller to manage the outflow of molten steel and reduce residual steel by delaying or dissipating vortex formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If manual or automatic roughing slag detection means is employed to detect steel slag and close the slide gate nozzle, then steel slag entrapment is reduced, but a large amount of clean molten steel remains in the ladle due to vortex suction

Engineering Contradiction:
Improveslag detection accuracyVSAvoidresidual molten steel
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent applies preliminary action by detecting the vortex formation state before slag entrapment occurs. The image recognition system identifies vortex development stages (dimple vortex to through vortex) and triggers preventive control actions (electromagnetic brake activation, nozzle opening degree adjustment) to destroy the vortex before it can suction slag, thereby avoiding both slag entrapment and residual steel waste

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback control through real-time monitoring of vortex formation using image recognition. The system continuously captures images, analyzes vortex state, and adjusts control parameters (electromagnetic brake force, nozzle opening) based on the detected vortex development stage, creating a closed-loop control system that optimizes the balance between slag removal and steel recovery

Inventive Principle:
Principle #23Feedback

2Reliability

If the slide gate nozzle is closed in time when steel slag exceeds the specified value, then slag entrapment is prevented, but teeming efficiency is reduced due to early termination

Engineering Contradiction:
Improveslag control reliabilityVSAvoidteeming efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system takes preliminary action by detecting vortex formation (which precedes slag entrapment) and intervening early with electromagnetic brake and nozzle control. This allows the teeming process to continue longer by preventing vortex-induced slag suction before it occurs, thereby improving both slag control reliability and teeming efficiency

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces the traditional mechanical slag detection method (based on slag flow observation) with an image recognition system that detects vortex formation. This substitution enables earlier and more accurate detection of the precursor condition (vortex) that leads to slag entrapment, allowing for optimized control that maintains both reliability and productivity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Loss of substance

If tilted-ladle teeming method is used to increase molten steel outflow, then residual steel is reduced, but slag entrapment is exacerbated due to increased vortex formation

Engineering Contradiction:
Improveresidual molten steelVSAvoidvortex-induced slag entrapment
Core Design Contradiction:
Loss of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent applies preliminary anti-action by using the image recognition system to detect vortex formation and then applying countermeasures (electromagnetic brake to disrupt rotation, nozzle control to adjust flow) that oppose and destroy the vortex before it can cause slag entrapment. This allows tilted-ladle teeming to proceed with reduced residual steel while preventing the harmful vortex effect

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The patent introduces an intermediary control system (image recognition + electromagnetic brake + nozzle control) that mediates between the tilted-ladle teeming process and the molten steel flow. This intermediary detects vortex formation and applies controlled interference to prevent slag entrapment while allowing the beneficial reduced residual steel effect to continue

Inventive Principle:
Principle #24Intermediary (Mediator)

4Object-generated harmful factors

If ladle slag weir technology is used to slow molten steel flow, then vortex formation is weakened, but teeming efficiency is reduced and residual steel increases

Engineering Contradiction:
Improvevortex-induced slag entrapmentVSAvoidteeming efficiency
Core Design Contradiction:
Object-generated harmful factorsVSProductivity

Solution Approach 1:

The patent applies dynamics by using real-time image recognition to detect vortex formation and dynamically adjusting control parameters (electromagnetic brake activation timing and strength, nozzle opening degree). This dynamic control allows the system to maintain high teeming efficiency while preventing vortex-induced slag entrapment only when and where needed, unlike the static slag weir approach

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes parameters dynamically based on detected vortex state. The electromagnetic brake force and nozzle opening degree are adjusted according to the vortex development stage identified by image recognition, allowing optimal balance between preventing slag entrapment and maintaining teeming efficiency, rather than using fixed parameter changes like slag weirs

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

Effectively reduces residual steel in the ladle, increasing molten steel yield by optimizing teeming control and preventing slag entrapment through precise management of vortex formation and dissipation.

Implementation Method 1

an electromagnetic brake, and a slide gate nozzle controller are provided; the vortex formation process is analyzed, and different optimization control strategies are adopted to inhibit or destroy vortex formation respectively

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

a ladle weight detector, and a molten steel flow field distribution detector are provided

Methodology Applied
Scientific EffectWeight measurement:

Implementation Method 3

a ladle weight detector, and a molten steel flow field distribution detector are provided; the vortex formation process is analyzed

Methodology Applied
Scientific EffectFlow field detection:

Implementation Method 4

a steel slag detector, and a slide gate nozzle controller are provided

Methodology Applied
Scientific EffectSlag detection:

Data Source

PatentEP3533535B1Control method and apparatus for inhibiting slag entrapment in ladle in last stage of pouring during continuous casting
Publication Date: 2021.11.17 BAOSHAN IRON & STEEL CO LTD
  • EP3533535B1 patent drawingFigure 1~2
  • EP3533535B1 patent drawingFigure 3
  • EP3533535B1 patent drawing

AI summary

A control method and apparatus for inhibiting slag entrapment in ladle (1) during continuous casting production. An optimal control model calculating unit (11) receives related signals and data sent by a ladle weight detector (4), a molten steel flow field detector (5), a slag detector (7), a sliding gate opening detector (9), and a process signal interface unit (10), performs calculation and analysis according to an optimal control model to obtain a corresponding optimal control strategy, and outputs the strategy to an electromagnetic brake (6) and a sliding gate controller (8) for slag entrapment inhibition control. Regarding the two processes where a vortex may be formed, by means of different optimal control strategies, which respectively inhibit or destroy the formation of a vortex, slag generation is postponed, and molten steel may flow out without bringing slag out, thereby reducing residual ladle steel and improving molten steel yield.