旋转管式微滤器中流体流动对过滤通量的影响  

Effects of the Rotational Fluid Flow on the Flux in a Rotating Annular Microporous Filter

作　　者：徐菡[1] 李建明[1] 陈文梅[1] 沈亮[1] 

机构地区：[1]四川大学化工学院,四川成都610065

出　　处：《高校化学工程学报》2003年第1期25-30,共6页Journal of Chemical Engineering of Chinese Universities

摘　　要：为讨论膜器环隙内流体流动对过滤通量的影响,运用了纳维-斯托克斯方程、连续性方程、达西定律等, 并结合稳定性理论,分别对主流体为去离子水和悬浮液的情况下环隙内流体的运动规律进行了分析。对于主流体为去离子水的情况,建立了过滤通量与膜器进出口压力降的关系,并与Belfort的实验数据进行了比较。结果证明当主流体为去离子水时(即无滤饼生成的理想情况下),流体旋转所产生的离心力对微滤推动力有削弱作用,当内膜管转速较小时,流体流动方式对过滤通量几乎无影响。对于悬浮液,由内膜管旋转所形成的剪切力对减少滤饼形成的作用甚微,而Taylor涡的形成是强化微滤的主要原因。最后提出了内膜管旋转管式膜器优化设计的新思想。Effects of the rotational fluid flow on the flux in a rotating annular microporous filter was studied. The simplified Navier-Stokes equations, continuity equation, and Darcy's law were used and then combining with the stability theory. The flow field in the annular gap of the filter using deionized water and dilute suspension as feed fluid, respectively, was analyzed. An equation describing the relationship between filtrate flux and pressure drop in the filter was derived. The curves calculated by the equation were compared with the Belfort's theoretical and experimental results, which showed that when deionized water was used as the fluid medium, the centrifugal force caused by the rotation of water, would weaken the driving force of micro-filtration, and when the rotating speed of membrane was low, the patterns of the fluid flow had little effect on the filtrate flux of the filter. Furthermore, with the dilute suspension, the equations describing the shear stresses for axial flow and rotating flow were derived, respectively. The results show that the axial shear stress is much higher than the tangential one under the given conditions, which means that it is the Taylor votex other than the tangential shear stress that plays an important role in improving the filter's capacity. A new strategy for designing the rotating annular microporous filter was proposed.

关 键 词：旋转管式微滤器 流体流动 过滤通量 旋转流动 数学模型 优化设计 微滤技术 

分 类 号：TQ028.8[化学工程] TQ051.893