2019 年 60 巻 9 号 p. 2008-2015
The main purpose of the present study is to evaluate mass transfer in an aluminum melting furnace stirred mechanically during flux treatment through water model experiment. Instead of the flux particles, model perlite particles were utilized, and the mass transfer between the pre-coated model particles and water bath was evaluated. Numerical simulation was also carried out to understand the flow pattern and mass transfer mechanisms. The fast impeller rotation speed enhanced the mass transfer. Besides, counter clockwise (CCW) rotation of impeller yielded larger mass transfer as compared to that of the clockwise impeller rotation (CW). The area of higher kinetic energy expanded with increase of impeller rotation speed, and the turbulent energy for the case of CCW rotation was higher compared to the CW case. The mechanism of the mass transfer enhancement under the CCW rotation conditions can be understood in terms of the turbulent energy at the free surface. The averaged downward flow was insufficient to cause the particle entrainment. On the other hand, the turbulent fluctuations were strong enough to cause the particle entrainment.