| Popis: |
Paper is devoted to study of the possibility of using a bottom induction stirrer with a rotating electromagnetic field for a force on melt of precious metals in a graphite crucible of an induction crucible furnace. The option of liquid metal stirring after melting is completed to achieve temperature uniformity was investigated. Numerical simulation of three depended problems was carried out: electromagnetic, hydrodynamic, and heat transfer in liquids. The optimization of supply current frequency magnitude was carried out by the Nelder-Mead method; the difference between the maximum and minimum temperatures in the melt volume four seconds after the start of stirring was chosen as the objective function, its minimization was achieved. Range of optimal frequencies of the supply current from 250 to 260 Hz was determined. The most effective frequency is f = 256.2 Hz, with it the temperature difference was ΔT = 8.6 °C. At the next stage, the process of mixing the metal during its melting will be considered. |
