某电厂超滤膜断丝原因分析及处理

Analysis and treatment of broken membrane of ultrafiltration membrane in a power plant

某电厂超滤系统额定出力为2464 t/h,超滤膜为外压式中空纤维膜,膜材料为改性聚醚砜(PES),单支膜面积60 m^(2)。超滤系统运行4年后,出水浊度增加,SDI值超出反渗透系统进水要求,经现场对超滤膜进行检测发现断丝严重,已经造成反渗透保安过滤器更换频繁、反渗透系统周期制水量降低、化学清洗次数增加的后果。经分析,超滤膜断丝的原因主要为膜丝材质和反洗方式不匹配以及膜的衰减老化,建议更换断丝严重的超滤膜并定期进行断丝检测。

The rated output of ultrafiltration system of a power plant was 2464t/h.ultrafiltration membrane was external pressure hollow fiber membrane,which was made of modified polyethersulfone(PES),whose single membrane area was 60 m^(2).After 4 years operation,the turbidity of effluent increased,and the SDI value exceeded the inlet water requirement of reverse osmosis system.It was found that the ultrafiltration membrane was serious broken on-site examination,which required frequent replacement of reverse osmosis security filter and yielded in reduction of periodic water production in reverse osmosis system,so times of chemical cleaning was increased.After analysis,the main reasons for the broken membrane of ultrafiltration membrane are the mismatch of the material and backwashing method of the membrane and the aging of the membrane.It was suggested that the seriously broken ultrafiltration membrane be replaced and regular check on membrane be conducted.