外环流气升陶瓷膜精制盐水研究

Application external loop airlift ceramic membrane to purification brine

采用气升式陶瓷膜过滤工艺进行盐水精制，研究了曝气量、跨膜压差和料液固含量对膜通量的影响，并计算了过滤阻力及表观能耗．实验结果表明，跨膜压差为60kPa，曝气量从200L／h增加到500L／h时，膜通量从200L／（m2·h）增加到360L／（m2·h），提高了80％；进一步提高曝气量，膜通量的增幅不大．曝气量为500L／h时，膜通量随跨膜压差的增大而线性增加．曝气条件下，固含量在0～25g／L范围内，随着固含量增大，膜通量略有下降，降幅小于10％．计算结果表明，曝气过程能够有效降低膜过滤阻力，基本消除浓差极化的影响；与错流过滤相比，通过气液两相流对膜过程的强化作用，气升过程能使袁观能耗显著降低．

Airlift membrane filter process was used for brine purification, the effects of gas sparging, transmembrane pressure （TMP） and soid content on permeate flux were studied while the filtration resistances and specific energy consumption were calculated. The experimental results showed that the permeate flux increased by about 80% from 200 L/（m2· h） to 360 L/（m2 · h） as gas velocities increasing from 200 to 500 L/h at the TMP of 60 kPa. Further increasing gas velocities did not improve permeate flux noticeably. The permeate flux and TMP had a linear relationship when the gas velocity was 500 L/h. As solid content increased from 0 to 25 g/L, the flux only decreased by 10%. According to the calculations, gas sparging reduced membrane fouling resistances effectively, eliminated concentration polarization. The specific energy consumption of airlift filtration process was lower than that of microfiltration attributing to the invigoration effect of gas-liquid two phase flow on membrane surface.