Multi-Mode® EMS
for slab casting
INTRODUCTION
Multi-Mode® EMS is Rotelec’s solution for quantitative control of liquid steel flow in the mold of slab casters. In slab casting, the flow pattern in the mold changes continuously as slab width, casting speed, argon flow rate and SEN conditions vary, and those variations directly affect slab quality, meniscus stability, surface cleanliness and machine regularity.
Multi-Mode® EMS is designed to keep steel flow within the preferred operating window even when casting conditions change. By adjusting the electromagnetic forces acting on the liquid steel, it gives slab casters real mold-flow control at the point where quality and productivity are won or lost.
HOW IT WORKS
The solution uses four independent linear stirrers positioned at mid-height in the slab caster mold. Because slab section prevents the use of rotative stirrers surrounding the cast product, slab casters use linear electromagnetic stirrers that generate traveling magnetic fields and operateon 2-phase AC current. In the Multi-Mode® EMS process, the four stirrers can slow down the liquid steel stream from the submerged entry nozzle (EMLS), accelerate it (EMLA), or put liquid steel in rotation up to the meniscus (EMRS).
This multi-mode architecture gives the system its distinctive strength. In practice, MM-EMS can actively correct single-roll, unstable, weak double-roll and strong double-roll flow patterns. It controls flow at the meniscus, washes the solidification front, equalizes temperature and helps achieve more uniform shell thickness. The result is more stable mold behavior and less dependence of final quality on changing operating conditions.
ROLE IN THE PROCESS AND PLANT INTEGRATION
Multi-Mode® EMS is particularly strategic where the mold is the main leverage point for improving slab and coil quality. In slab casting, the challenge is not simply to stir the steel, but to direct its flow toward the most favorable pattern for the grade and casting condition. MM-EMS offers a controlled combination of slowing-down, accelerating and rotative functions tailored to real production variability.
From a plant perspective, integration requires a full system view. MM-EMS is developed around the actual mold interface, available space, power supply, automation and the measurement and protection systems already present on the machine. The stirrers are mounted behind the backup plates and, depending on the layout, may be fixed directly to the mold or installed on a retractable manipulator.
For slab casters aiming at advanced mold-flow control and a better balance between quality and productivity, Multi-Mode® EMS is a high-impact process solution. Contact Rotelec to assess the configuration best suited to your slab caster, grades and operating envelope.
KEY BENEFITS
- Quantitative control of steel flow in the mold, enhancing stable and symmetrical flow patterns over a wide operating range with correction of weak, unstable and excessive flow conditions.
- Better control of shell thickness uniformity and homogenization of lubrication helps reduce longitudinal cracks, lower breakout alarms and improved casting continuity, with positive effects on speed and sequence reliability.
- Washing effect and controlled flow reduce the defects associated with both excessive flow and weak or unstable flow, including slivers, alumina inclusions, blowholes and pinholes.
- Operational flexibility across changing slab widths, casting speeds and product mixes without compromising slab quality.
- Improved productivity and profitability through reduced downgrade, less scrap, lower scarfing/grinding costs, higher yield and rapid return on investment.
