A comprehensive mathematical model has been developed to describe the interaction of the multiple physics fields during the conventional DC casting and LFEC (low frequency electromagnetic casting) process. The model i...A comprehensive mathematical model has been developed to describe the interaction of the multiple physics fields during the conventional DC casting and LFEC (low frequency electromagnetic casting) process. The model is based on a combination of the commercial finite element package ANSYS and the commercial finite volume package FLUENT, with the former for the calculation of the electromagnetic field and the latter for the calculation of the magnetic driven fluid flow, heat transfer and solidification. Moreover, the model has been verified against the temperature measurements obtained from two 7XXX aluminum alloy billets of 200mm diameter, cast during the conventional DC casting and the LFEC casting processes. In addition, a measurement of the sump shape of the billets were carried out by using addition melting metal of Al-30%Cu alloy into the billets during casting process. There was a good agreement between the calculated results and the measured results. Further, comparison of the calculated results during the LFEC process with that during the conventional DC casting process indicated that velocity patterns, temperature profiles and the sump depth are strongly modified by the application of a low frequency electromagnetic field during the DC casting.展开更多
The mechanisms of heat transfer through the sinter beds of the MEBIOS process are discussed and their comprehensive mathematical model is proposed. The MEBIOS process, the concept of which has been proposed ear- lier ...The mechanisms of heat transfer through the sinter beds of the MEBIOS process are discussed and their comprehensive mathematical model is proposed. The MEBIOS process, the concept of which has been proposed ear- lier by the authors, allows using both coarse and fine particles of iron ores in the same sinter bed. The study includes two parts. The first part describes the model content and the results of its experimental verification. The model ac- counts for coal combustion, limestone decomposition, moisture evaporation/condensation, and melting/solidifying of solid phases. The model predictions are in good agreement with the experimental data. Typical numerical results of the sintering process and the key parameters influencing the process efficiency are discussed in the second part of the study.展开更多
The results of numerical simulation of the mosaic embedding iron ore sintering （MEBIOS） process according to the model presented in the first part of the study are introduced. The main objective of the second part i...The results of numerical simulation of the mosaic embedding iron ore sintering （MEBIOS） process according to the model presented in the first part of the study are introduced. The main objective of the second part is the elucidation of key factors influencing the process efficiency, particularly the sintering completeness, velocity of the heat wave propagation and maximum temperature achievable in the pellet during the wave propagation. Numerical results reveal that the mass fraction of coal, diameter of coal particles and air inlet velocity are of prime importance in determining efficiency of the MEBIOS sintering process.展开更多
Aluminum has high recyclability and promising future,so aluminum recycling is important for the future society.However aluminum recycling has some problems;one problem is inclusions remaining in final aluminum product...Aluminum has high recyclability and promising future,so aluminum recycling is important for the future society.However aluminum recycling has some problems;one problem is inclusions remaining in final aluminum products.In this study,we have proposed a new separation process of inclusion particles from molten aluminum;it is the electromagnetic cyclone separator,which consists of the liquid cyclone and the electromagnetic separator.We carried out water model experiments,in which the magnetic separation was used instead of the electromagnetic separation.A theoretical model to estimate the separation efficiency was developed and the results agreed with the water model experiments.The theoretical model was used to estimate the separation performance of the electromagnetic cyclone separator for molten aluminum,and it was predicted that the separator was effective clarification process for aluminum recycling.展开更多
文摘A comprehensive mathematical model has been developed to describe the interaction of the multiple physics fields during the conventional DC casting and LFEC (low frequency electromagnetic casting) process. The model is based on a combination of the commercial finite element package ANSYS and the commercial finite volume package FLUENT, with the former for the calculation of the electromagnetic field and the latter for the calculation of the magnetic driven fluid flow, heat transfer and solidification. Moreover, the model has been verified against the temperature measurements obtained from two 7XXX aluminum alloy billets of 200mm diameter, cast during the conventional DC casting and the LFEC casting processes. In addition, a measurement of the sump shape of the billets were carried out by using addition melting metal of Al-30%Cu alloy into the billets during casting process. There was a good agreement between the calculated results and the measured results. Further, comparison of the calculated results during the LFEC process with that during the conventional DC casting process indicated that velocity patterns, temperature profiles and the sump depth are strongly modified by the application of a low frequency electromagnetic field during the DC casting.
文摘The mechanisms of heat transfer through the sinter beds of the MEBIOS process are discussed and their comprehensive mathematical model is proposed. The MEBIOS process, the concept of which has been proposed ear- lier by the authors, allows using both coarse and fine particles of iron ores in the same sinter bed. The study includes two parts. The first part describes the model content and the results of its experimental verification. The model ac- counts for coal combustion, limestone decomposition, moisture evaporation/condensation, and melting/solidifying of solid phases. The model predictions are in good agreement with the experimental data. Typical numerical results of the sintering process and the key parameters influencing the process efficiency are discussed in the second part of the study.
文摘The results of numerical simulation of the mosaic embedding iron ore sintering （MEBIOS） process according to the model presented in the first part of the study are introduced. The main objective of the second part is the elucidation of key factors influencing the process efficiency, particularly the sintering completeness, velocity of the heat wave propagation and maximum temperature achievable in the pellet during the wave propagation. Numerical results reveal that the mass fraction of coal, diameter of coal particles and air inlet velocity are of prime importance in determining efficiency of the MEBIOS sintering process.
基金Item Sponsored by Grant-in-Aid for Scientific Research (A) in 2010-2012 (22246097) From the Japan Society for the Promotion of Science (JSPS)
文摘Aluminum has high recyclability and promising future,so aluminum recycling is important for the future society.However aluminum recycling has some problems;one problem is inclusions remaining in final aluminum products.In this study,we have proposed a new separation process of inclusion particles from molten aluminum;it is the electromagnetic cyclone separator,which consists of the liquid cyclone and the electromagnetic separator.We carried out water model experiments,in which the magnetic separation was used instead of the electromagnetic separation.A theoretical model to estimate the separation efficiency was developed and the results agreed with the water model experiments.The theoretical model was used to estimate the separation performance of the electromagnetic cyclone separator for molten aluminum,and it was predicted that the separator was effective clarification process for aluminum recycling.
