气升式陶瓷膜装置过滤钛硅分子筛悬浮液  

Filtration of titanium silicalite zeolite suspensions by airlift ceramic membrane equipment

作　　者：张向荣[1] 景文珩[1] 邢卫红[1] 张峰[1] 

机构地区：[1]南京工业大学膜科学技术研究所国家特种分离膜工程技术研究中心,江苏南京210009

出　　处：《化学工程》2013年第8期62-66,共5页Chemical Engineering(China)

基　　金：国家杰出青年基金资助项目(21125629);国家自然科学基金资助项目(21076102);江苏省环保科研课题项目(201018);江苏省高校自然科学基金项目(10KJB530002)

摘　　要：为克服膜污染,提高膜通量,文章将曝气引入到陶瓷膜过滤过程中,计算了曝气量对液相循环流速、气含率以及膜面剪切力的影响。采用气升式陶瓷膜过滤装置,以平均孔径为200 nm的ZrO2陶瓷膜为分离介质,考察了固含量(质量浓度)、曝气量、跨膜压差对钛硅分子筛悬浮液固液分离性能的影响。结果表明:曝气量增大,液相循环流速和气含率随之增大;曝气量在416—2 333 mL/min内,气液二相流流型为弹状流,气弹区膜面剪切力是液弹区的3—10倍。陶瓷膜对钛硅分子筛的截留率为100%;当固含量为1%时,曝气量由100 mL/min增大至850 mL/min,膜稳定通量增大了33%,进一步增大曝气量,通量开始下降。膜的稳定通量随着固含量的增大而降低。当曝气量为850 mL/min,固含量为1%时,跨膜压差由0.1 MPa增大至0.2 MPa,稳定通量降低了41%,但进一步增大跨膜压差到0.3 MPa时,稳定通量又表现出增大趋势。对膜过滤阻力的计算分析结果表明:曝气作用能减轻浓差极化,但不能消除滤饼与膜孔堵塞污染。To overcome the membrane fouling problems and increase the flux of membrane, the aeration process was introduced into the ceramic membrane filtration process. Liquid circulation velocity, gas holdup and membrane surface shearforce were calculated under different aeration conditions. The filtration of titanium silicalite （TS-1） zeolite suspension by airlift ceramic membrane equipment was performed. The effect of solid content （mass concentration）, aeration rate and transmembrane pressure on the membrane filtration performance was investigated systematically by using ZrO2 ceramic membrane with a pore size of 200 nm. The results show that the liquid circulation flow rate and gas holdup increase when the aeration rate increases ; in addition, the pattern of gas-liquid two phases is slug flow when the aeration rate increases from 416 to 2 333 mL/min, and the membrane surface shearforce in the gas slug area is 3-10 times of that in liquid slug area. The rejection of TS-1 by ceramic membrane can reach 100%. When solid content is 1%, and the aeration rate increases from 100 to 850 mL/min, the steady flux is increased by 33%, and then decreases when the aeration rate further increases. Steady flux decreases with the increase of solid content. When solid content is 1%, aeration rate is 850 mIJmin, the trans-membrane pressure increases from O. 1 MPa to 0.2 MPa, and the steady flux is reduced by 41%, and then increases when the trans-membrane pressure is further increased to 0.3 MPa. By calculation and analyses of membrane filtration resistance, the aeration process is effective in the control of concentration polarization, however, it has little effect on the removing of cake and pore blocking fouling.

关 键 词：气升 膜过滤 曝气 钛硅分子筛 

分 类 号：TQ028.8[化学工程]