电渗析隔板网丝形状优化及CFD模拟

The Optimization of Electrodialysis Spacer-obstructed by CFD

电渗析技术已广泛应用于废水处理和特种分离等领域,隔板作为电渗析器必不可少的一部分发挥着重要作用。本文利用计算流体动力学(CFD)方法对隔板流道中网丝的形状进行了3D模拟研究。考查了网丝形状对流道中流体速度分布、壁面剪切力分布和水流压降的影响。结果表明,采用菱形网丝可使流道内流速分布和膜表面剪切应力分布更加均匀,流动死区面积更小,传质更加均匀,能够有效减缓浓差极化现象,同时较低的压降能够节省能耗,降低运行成本。

Electrodialysis is widely used in the fields of waste water treatment and special separation.Spacer plays an important role as an essential part of electrodialysis.The shape of the spacer-obstructed was simulated by CFD method.The velocity distribution,the distribution of the wall shear and the pressure drop of the water flow in the flow channel of three different shapes(square,circle,and rhomb)was examined.The results showed that the velocity distribution and the shear stress distribution on the membrane surface in the rhomboid spacer-obstructed were more uniform,the area of the flow dead zone is smaller,the mass transfer was more uniform.It was beneficial to the reduction of concentration polarization.Meanwhile,it has the lowest pressure drop and can save energy consumption and reduce the running cost.