Local Lorentz force flowmeter at a continuous caster model using a new generation multicomponent force and torque sensor

Abstract

Lorentz force velocimetry is a non-invasive velocity measurement technique for electrical conductive liquids like molten steel. In this technique, the metal flow interacts with a static magnetic field generating eddy currents which, in turn, produce flow-braking Lorentz forces within the fluid. These forces are proportional to the electrical conductivity and to the velocity of the melt. Due to Newton's third law, a counter force of the same magnitude acts on the source of the applied static magnetic field which is in our case a permanent magnet. In this paper we will present a new multicomponent sensor for the local Lorentz force flowmeter (L2F2) which is able to measure simultaneously all three components of the force as well as all three components of the torque. Therefore, this new sensor is capable of accessing all three velocity components at the same time in the region near the wall. In order to demonstrate the potential of this new sensor, it is used to identify the 3-dimensional velocity field near the wide face of the mold of a continuous caster model available at the Helmholtz-Zentrum Dresden-Rossendorf. As model melt, the eutectic alloy GaInSn is used.

Numerical calibration of a multicomponent local Lorentz force flowmeter

“…26.9 µNm. According to preliminary simulations of our results in [3], the expected order of magnitude of T z at the Mini-LIMMCAST facility is in this range using a larger CSMA than the one addressed in this paper. From the theoretical point of view, it could be interesting to study the effect of the air gap on the axial torque component for generic non-axisymmetric fields within the two-dimensional approach.…”

“…A new-generation L2F2 is able to measure all three force and three torque components acting on the magnet system. With this sensor attached to a 15 mm cubic magnet, we were able to obtain information on the three-dimensional velocity structure of GaInSn near the wide face of the mold of a continuous casting model, namely, the Mini-LIMMCAST facility at Hemholtz-Zentrum Dresden-Rossendorf [3]. The known double-roll structure, typical for continuous casting of steel, was clearly identified by either the force or the torque signal.…”

Torsion balance-based system for high-precision force measurement in horizontal plane: part I. Development concept

“…In LFV, a special type of a magnet system weighing approximately 1 kg is used as one of the integral parts of the application. The magnet system is suspended from a force measurement system (the other integral part of the application), which measures the Lorentz forces acting on the magnet in the horizontal direction [1][2][3]. In several applications, the LFV is specially designed to meet measurement requirements for weakly conducting liquids, such as glass-melts whose electrical conductivity is typically about 10 −6 S m −1 .…”

Experimental calibration procedures for rotating Lorentz-force flowmeters

“…Additionally, because RLFF's are non-contact devices, they are able to operate upon chemically aggressive and/or high-temper ature fluids such as molten metals. These features make RLFF's useful instruments that could benefit the nuclear [3,4], concentrated solar power [5,6], and metallurgical/casting industries [7,8].…”