残极集气系统对无组织烟气减排的作用

Effect of Residual Gas Collection System on the Emission of Fugitive Emission Gas

残极冷却过程中的无组织排放是铝电解HF进入大气的主要方式.针对该问题,开发了残极集气系统,研究了不同烟气流速下,残极集气系统内残极的温度变化、HF散发规律,以及该系统对HF无组织排放的减排效果.结果表明,残极集气系统可有效降低残极冷却过程中的无组织排放.残极进入集气系统的初始温度为920℃,降温速度先快后慢.HF质量浓度随烟气流量加大而增加,随烟气温度降低而减少,通过拟合函数进行了相关性分析.运行4 h时,HF的累计散发量达到总散发量的95%以上.在最优烟气流速4000 m^(3)/h时,氟化物的无组织排放较无减排措施时降低0.201 kg/t(吨铝减排量).

Fugitive emission during residual anode cooling is the main way for aluminum electrolytic HF entering the atmosphere.In response to this problem,a residual gas collection system was developed.Besides,the residual temperature,HF emission and the fugitive emission reduction effect of the system were studied under different gas flow rates.The results show that the residual gas collection system can reduce HF fugitive emission effectively.The initial temperature of the residual anode is 920℃.The temperature drops quickly and then slowly.The HF concentration increases with the increase of the flue gas flow,and decreases with the decrease of the flue gas temperature.Correlation analysis is carried out through the fitting function.After 4 h,the cumulative HF emission reaches more than 95%of the total emission.HF fugitive emission is reduced by 0.201 kg/t at the optimal gas flow rate(4000 m^(3)/h),compared with no HF emission reduction measures.