Imaging molten steel flow profiles

Abstract

Control of molten steel delivery in continuous casting is critical to ensure stability of the meniscus and satisfactory mould flow patterns, which in turn are determinants of steel cleanness and surface quality. Considerable effort has been expended over the last 10 years in optimizing the design of the metal delivery system, particularly the pouring nozzle, to enable the consistent production of high quality steel at high throughput. This paper looks forward to possible systems that are capable of topographically imaging the distribution of molten steel flows in these applications. The paper will concentrate on the feasibility of using electromagnetic methods. The paper will present some initial results and an overview of the image reconstruction process used will also be included.The paper will conclude with a discussion of possible future developments, such as the use of a tomographic or multifrequency approach, future research on the reconstruction image procedures and the potential for visualisation and flow measurement. There is a need for further research in this area and some priority areas for future work will be suggested.Downloaded From: http://proceedings.spiedigitallibrary.org/ on 08/24/2015 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx

A three-dimensional inverse finite-element method applied to experimental eddy-current imaging data

“…The MIT technique has been considered in situations where the target materials of interest are characterized by electrical conductivity, as is the case of monitoring of the steel flow in a continuous casting nozzle [8]. Fig.…”

“…The inverse solver is an optimization algorithm that finds a to minimize a suitable error functional. Reformulation of the inverse problem to include prior information is known as regularization and it can be expressed as a minimization of the functional (8) where is a penalty term. The Jacobian matrix is a discretization of .…”

“…Image reconstruction is an inverse problem where the measured voltages are given and the spatial distribution of electromagnetic properties of the object material need to be found. Linear reconstruction methods [8], [9] are fast and can be successfully applied to isolated objects. In general, it is necessary to use nonlinear reconstruction methods.…”

“…To be practically usable, it is very important for an image reconstruction method Digital Object Identifier 10.1109/TMAG.2006.871255 to be tested with experimental data. In this paper, we present the reconstruction results for laboratory tests as well as experimental results from a practical test in molten steel flow visualization [8]. Reconstruction of the MIT images requires a forward solver so that predicted data can be compared with measured data.…”

Simulation research of impact of number of coils in EMT sensors on reconstructed images quality

“…Electromagnetic tomography is an emerging measurement technique for visualizing cross-sectional images of electrically conductive or magnetically permeable materials based on the induced voltages obtained from the detection coils evenly distributed around the vessels and pipelines [1 -2]. EMT has several advantages over other process tomography techniques such as non-invasive, non-contact, low cost, high speed, small size and easy to use, so it has great potential and can be used to both industrial and biomedical applications such as multiphase flow measurement [3][4], visualization of molten metal [5][6], nondestructive testing [7], brain oedema detection [8], et al EMT has been extensively developed over the past two decades including hardware design, image reconstruction algorithms and potential applications. As for EMT sensors, the commonly used sensor geometry is circular shape with 8 coils around the periphery of the sensor.…”