关键词: 中心龙卷流型搅拌槽, 对数螺旋导流板, 结构优化, 数值模拟, 氧化镁

Abstract: The internal flow field characteristics in a central tornado flow stirred tank are simulated qualitatively based on the computational fluid dynamics, the effects of angle of logarithmic spiral deflector, degree of polar angle, initial radius and height of deflector on the flow field in the tank examined, and the deflector structure is optimized for production of nanometer magnesia with the tank. The results show that the dimensions of deflector have significant effect on the flow field. When the internal diameter of stirred tank is 300 mm, the six-straight-blade-disk turbine used, the angle of logarithmic spiral deflector 45o, the polar angle 60o, the initial radius 20 mm, and the height of deflector 30 mm, two circular flow patterns form, the effect of tornado flow is obvious and that of mixing better. Such optimization has been verified in the experimental preparation of nanometer magnesia.

Key words: central tornado flow stirred tank, logarithmic spiral deflector, structural optimizatio, numerical simulation, magnesia