Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

The properties of the mould flow are significant for the casting quality at the continuous casting of steel. To investigate the flow behaviour model experiments were performed using liquid metal melts with a low melting temperature. Thereto adequate imaging measuring techniques for liquid metal flows are required. We will present three methods: the Ultrasound Doppler Velocimetry (UDV) and the Contactless Inductive Flow Tomography (CIFT) to measure two-dimensional velocity fields in the mould and the Mutual Inductance Tomography (MIT) to measure the two-phase flow distribution in the SEN. The UDV method by means of ultrasonic array transducers provides spatial- and time-resolved measurements at a measuring area of 24 × 24 voxel with frame rates up to 30 fps. A method based on the application of ultrasonic wave guides is presented to extend the limited temperature range of conventional ultrasonic transducers (up to 200°C) to temperatures up to about 700°C. CIFT facilitate measurements of the global flow structure with frame rates of 1 fps. Due to its feature as a contactless measuring method it can be applied at facilities operating at room temperature as well as much higher temperatures. The MIT as well a contactless measuring principle may resolve the two-phase flow distribution in the SEN with up to 20 fps. All three methods were successfully applied at a small-scale continuous casting model based on the metal alloy GaInSn liquid at room temperature and are currently adapted to a large-scale casting model applying the alloy BiSn in a temperature range of 200°C to 350°C.