電解質(zhì)流場的影響
(1. 浙江大學(xué) 能源清潔利用國家重點實驗室, 杭州 310027;
2. 中南大學(xué) 冶金科學(xué)與工程學(xué)院, 長沙 410083)
摘 要: 對預(yù)焙鋁電解槽陽極底部開排氣溝時周圍電解質(zhì)流場進行計算, 發(fā)現(xiàn)部分陽極氣體可以通過排氣溝向外排放, 減少氣泡在陽極底部停留時間和陽極底掌氣泡覆蓋率, 從而有利于降低極間電阻壓降和陽極效應(yīng)系數(shù), 減少電解能耗； 另一方面氣體帶動電解質(zhì)進入排氣溝, 然后進入電解槽側(cè)部通道, 擴大了電解質(zhì)循環(huán)通道, 促進了陽極周圍電解質(zhì)流動和槽內(nèi)的傳質(zhì)傳熱, 有利于保持電解正常進行, 相比之下排氣溝為通溝時較非通溝更有利于保持電解質(zhì)流動穩(wěn)定；同時由于排氣溝促進了陽極氣體排放, 使鋁液與陽極氣體發(fā)生“二次反應(yīng)”（即電解還原的鋁卷入電解質(zhì)中被陽極氣體重新氧化）的機會減少, 有利于提高鋁電解電流效率。
關(guān)鍵字: 預(yù)焙陽極； 排氣溝； 陽極氣體； 電解質(zhì)流場
bottom of prebaked carbon anodes on
bath flow pattern in aluminum reduction cells
ZHOU Hao1, CEN Ke-fa1
（1. State Key Laboratory of Clean Energy Utilization,
Zhejiang University, Hangzhou 310027, China;
2. School of Metallurgical Science and Engineering,
Central South University, Changsha 410083, China）
Abstract: Simulations on the bath flow fields around a prebaked carbon anode with gas discharging grooves at the bottom which could be applied on aluminum reduction cell was conducted. The results reveal that with the help of the grooves, anode gas discharging is facilitated, residence time of bubbles in the interpolar gap( or ACD) and the bubbles coverage of the anode bottom can be reduced, which greatly contributes to the decrease of the voltage drop in ACD and anode effects, so the energy consumption of the aluminum production can be lowered. On the other hand electrolyte dragged by gas bubbles goes into the grooves, then to the side channel of the cell, passageway for the bath circulation is widened, a relatively smooth bath circulation around the anode will be formed, which enhances the heat and mass transmission, therefore a good electrolysis operation can be obtained. Compared the grooves which extend through the whole length of the anode bottom with those do not, the former are more propitious to the stability of the bath flow, meanwhile as the grooves facilitate the gas venting, the so called “second reaction”, i.e. the aluminum reduced diffuse into the bath and react with the anode gas again, could be restrained to some extent, which would be beneficial to the improvement of the current efficiency.
Key words: prebaked carbon anodes; gas discharging grooves; anode gas; bath flow fields
