【摘要】 实验研究了旋转直线切向流管式膜器环隙切剖面的流场特征 .通过建立膜滤实验装置系统 ,首次采用PIV激光粒子成像测速系统定量实测了旋转直线切向流管式膜器在不同工况 ,即不同流体压力、不同入口流量或不同入口切向流速等操作参数下环隙切剖面的流线图和涡量图 ,并在环隙切剖面内测出了流体切向速度和轴向速度及其分布规律 :①在非涡区域 ,无论操作参数如何变化 ,在横坐标相同时 ,靠近旋转切向流入口方向的速度比远离入口方向的速度要大 ;涡内区域流体的速度一般小于涡外部的流体速度 ;涡心处速度最低 ,而且切向速度一般为 0 ;涡心附近的切向速度小于轴向速度 .②在实验工况下 ,涡边缘附近的切向和轴向速度均为膜器环隙间平均轴向流速的 1～ 2倍 ;形成椭圆涡面上的最大切向和轴向速度一般为膜器环隙间平均轴向流速的 2～ 6倍 .③环隙切剖面上形成的涡 ,其内部流体都要与涡外部的流体进行质量交换 .涡外流体大量涌入涡内部 ,能够防止颗粒过早堵塞膜管更多还原

【Abstract】 A new type of polypropylene tubular membrane apparatus of rotating cross flow was designed to study experimentally the flow field characteristics of the tangential section of the membrane annular gap. The authors designed rotary linear tangential flow tubular membrane separator and its test system for the first time. Through the system, the flow field of rotary linear tangential flow with the advanced Particle Image Velocimetry (PIV) was tested for the first time. A lot of streamlines and vorticity maps of the tangential section of separator in different operation conditions were obtained. The velocity distribution characteristics were analyzed quantitatively: ① At non vortex area, no matter how the operation parameters change, the velocity near to rotary tangential flow entrance was higher than the velocity far from entrance at the same radial coordinates. At vortex area, generally the flow velocity of inner vortex was lower than the outer vortex. At the vortex center, the velocity was lowest, the tangential velocity were equal to zero generally. At the vortex center zone, the tangential velocity was less than the axial velocity. ② Under test operations, the tangential velocity and axial velocity of vortices borders are 1～2 times of average axial velocity of membrane module annular gap. The maximum tangential velocity and axial velocity of ellipse vortices were 2～6 times of average axial velocity of membrane module annular gap. ③ The vortices that are formed on the tangential section, there existed mass transfer between inner and outer parts of fluid. Much fluid of outer vortices got into the inner ones, which was able to prevent membrane tube from particles blocking up very soon.更多还原