阳极更换及铝液高度对电解槽内铝液流速场的影响

Effect of anode change and metal height on flow field of metal pad in aluminum reduction cells

采用k-ε二方程法和SIMPLE算法对190 kA大型预焙阳极铝电解槽分别在槽况较为理想、更换阳极、炉底存在结壳、不同铝水平以及阳极长包情况下的铝液流速场进行了三维计算。结果表明: 电解槽中金属铝液主要表现为水平流动, 但在槽边部也表现出明显的垂直方向流动; 在理想槽况下, 铝液中最大水平流速为11.9 cm/s, 平均流速为3.5 cm/s; 换极、炉底结壳和阳极长包时, 在相应位置的铝液中出现显著的环行流动, 铝液流动形式发生变化; 换极时铝液最大流速(为13.1 cm/s)较理想槽况有较大增加, 但平均流速变化不大; 炉底存在较小结壳时, 铝液流速增加不大; 阳极长包时, 铝液流速则大大增加, 最大水平流速达24 cm/s, 而当铝水平适当降低, 铝液流动形式和流速未发生明显变化。

The k-ε two-equation and SIMPLE calculation methods were adopted to calculate the flow field of 190kA prebaked anode aluminum reduction cells under ideal condition, anode change (AC), different metal height, bottom ridge and anode spikes. The results show that the flow of metal pad is horizontal, but the flow of ledge is vertical. Under normal cell status, the maximum horizontal flow speed of metal is 11.9cm/s, the average flow is 3.5cm/s. While under AC, bottom ridge and anode spikes, circular flow occurs at corresponding locations. The maximum flow speed of AC increases than that of the normal cell status, and the maximum flow speed of AC is (13.1cm/s). While there is small ridge on the bottom of cell, the flow of metal increases unobviously. The flow of metal increases under anode spike, and the maximum flow is 24cm/s. Lower metal height has little effect on both flow pattern and flow speed.