电磁场在冶金与材料加工中应用课程阅读文献1 proceeding.pdfVIP

Flow Rate Measurement in Liquid Aluminum using Lorentz Velocimetry Ch. Karcher, Y. Kolesnikov, V. M henya, and A. Thess Institute of Thermodynamics and Fluid Mechanics Ilmenau University of Technology P.O. Box 10 05 65, D-98684 Ilmenau, Germany Lorentz Velocimetry (LFV) is a newly developed non-contact method used to measure the flow rate in hot and aggressive electrically conducting fluids such as liquid aluminum. Physically, the measuring pr iple is based on the well-known fact that a breaking Lorentz is induced in the melt when a ma ic field is applied to moving liquid metal. In turn, an opposite drag acts on the device that generates the ma ic field. This is proportional to the melt flow rate and can be measured externally. At Ilmenau University of Technology we have constructed a prototype of such a Lorentz flow meter. It has been especially designed to measure melt-flow typically occurring during the production of secondary aluminum. This work presents the tests of the prototype under industrial conditions. The measurements were carried out in an open channel within which aluminum melt is transported by gravity from a rotary furnace to a holding furnace. We record the Lorentz , the height of the -surface flow, and the temperature of the ma system. The evaluation of the data shows that our prototype has an accuracy of about 2% in predicting the flow rate. Introduction During the production of secondary aluminum [1], [2], aluminum scrap like cans, foils, and cuttings is molten in big rotary furnaces holding up to 30 tons. Melting salt (NaCl + KCl) is