铝电解槽熔体中电流分布的数值计算

在电解槽三维电位场计算的基础上,对电解槽在不同工艺条件下及不同结构时的电流场进行了数值计算:1)伸腿长度为零的理想情况;2)伸腿伸至阳极底部;3)不同铝水平及换极;4)泄流式电解槽.通过分析发现,铝液中y 向电流密度沿阴极长度方向表现出先增后降的趋势,Jy的幅值随铝液层面降低有所增加.在伸腿伸至阳极底部时,在槽边部会出现较大的逆向电流,伸腿越长,逆向水平电流越大.铝液层面中垂直电流密度沿阴极碳块长度方向自里向外呈现增加趋势,且铝液层面越低,电流密度变化梯度越大.铝液中x向电流可以忽略,且随铝水平变化较小.泄流式电解槽熔体中存在较大的电流密度集中现象,炉底压降相对较大.

Numerical calculation of current distribution in the metal pad of aluminum reduction cells

Based on the numerical calculation of 3-D potential distribution in aluminum reduction cells, the electrical current distribution in the metal pad is calculated under the following three conditions: 1)ideal pot ledge; 2)ledge extending to anode bottom;3)different metal heights and anode changes; 4)drained cathode cell. It is found that Jy in metal pad increases first and then decreases along the cathode longitudinal axis, and it increases slightly with the lowering of metal levels. While the ledge extends to anode bottom, there is a big reverse current toward the cell center at cell sides, and the longer the ledge is, the bigger will be the reverse current density. The vertical current density in the metal pad increases along longitudinal axis of cathode block from cell center to cell sides and the current density gradient increases with lowering of metal levels. Jx is almost negligible in the metal pad. Because of over-concentration of current density in the metal of drained cathode cell, it has a higher cathode voltage drop.