Oscillating Strand Stirrer for Reducing Bloom Center Segregation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Center segregations occur in blooms cast using existing continuous casting methods, despite the use of strand stirrers, and there is a need for a more effective and reliable method to reduce these segregations.
Innovation Solution
A single strand stirrer is moved with an oscillating stroke between upper and lower reversal points during the solidification time, with the oscillation stroke and reversal points adjusted to the solidification behavior of the steel strand, and the alternating current intensity and frequency varied to optimize stirring efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single strand stirrer is used, then device complexity is reduced, but manufacturing precision (center segregation reduction) is insufficient
Solution Approach 1:
The strand stirrer is moved with an oscillating stroke between upper and lower reversal points during the solidification time, transforming a static stirring mechanism into a dynamic one that covers the entire length of the steel strand, thereby achieving effective center segregation reduction with a single stirrer
Solution Approach 2:
The oscillating motion of the strand stirrer creates periodic action that systematically covers different regions of the steel strand during solidification, enabling a single stirrer to perform the functions that would traditionally require multiple stationary stirrers
2Manufacturing precision
If multiple strand stirrers are used, then manufacturing precision (center segregation reduction) is improved, but device complexity increases
Solution Approach 1:
The patent combines the functions of multiple stationary stirrers into a single mobile stirrer that oscillates between upper and lower reversal points, merging multiple stirring zones into one dynamically adjustable stirring mechanism that covers the entire steel strand length
Solution Approach 2:
The single strand stirrer performs multiple functions by moving between different positions (upper and lower reversal points) during solidification time, acting as both a typical stirrer and a final stirrer, thereby eliminating the need for separate stirrers for different zones
3Manufacturing precision
If the strand stirrer is moved with oscillation stroke, then manufacturing precision is improved, but use of energy increases
Solution Approach 1:
The oscillating motion of the strand stirrer between upper and lower reversal points creates dynamic stirring action that effectively prevents center segregation throughout the entire steel strand, achieving superior manufacturing precision that justifies the additional energy consumption
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
This approach effectively reduces center segregations along the entire length of the cast steel strand, achieving high interior quality with a single stirrer that typically performs the functions of both a typical and final stirrer, enhancing the internal quality of the steel strand.
Implementation Method 1
the liquid core is stirred by means of a strand stirrer during the solidification time
Implementation Method 2
the strand stirrer is moved during the solidification time with an oscillation stroke in an oscillating manner between an upper and a lower reversal point
Implementation Method 3
the alternating current intensity and frequency varied to optimize stirring efficiency
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
Liquid steel (1) is poured from above into a continuous mold (2). A steel strand (3) with an already solidified strand shell (4) and a still liquid core (5) is drawn from the bottom of the continuous mold (2). The steel strand (3) is fed from above into a holding device (6) without changing direction, where it remains during a solidification period. During this period, the steel strand (3) gradually solidifies into a billet or ingot. During solidification, the liquid core (5) is stirred by a strand agitator (9). Furthermore, during solidification, the strand agitator (9) is moved vertically along the steel strand (3) between an upper and a lower reversal point (P1, P2) with an oscillation stroke (h).