Study Of Three-dimensional Velocity Of Vortices In Rotary Tubular Membrane Separator

Membrane separation is a new and developing high technology, it had a lot of advantages, such as separating at normal atmospheric temperature, low energy consuming, simple device, easy control, easy repair, wide extent using. Rotary tubular membrane micro-filtration is a dynamic separating technology proposed in 1980's. When using rotary tubular membrane, the Taylor vortices that appear in the annular gap can efficaciously control membrane fouling and concentration-polarization, and can solve the difficult problem which hinders the development of membrane separation. Rotary tubular membrane is very promising, but the study is still on its early stage.In 2001 year, Li Haibo and Li Qiang take use of Particle Image Velocimetry System (PIV) to test velocity field of the annular gap of rotary tubular membrane separator in Peking University. This paper takes use of PIV test to analysis the velocity field of meridional and latitudinal planes in annular gap and analyse velocity field characteristics systematically.Firstly, when the rotate speed of inner cylinder is different and there is no axial and permeating flow, this paper obtains velocity vectors of Taylor vortices in meridional plane of separator from the datum of Particle Image Velocimetry test. Then this paper analyses the testing results with Tecplot software, and obtains radial and axial velocity distribution characteristics of meridional plane.Secondly, this paper obtains velocity vectors of meridional plane and latitudinal plane of separator from the datum of Particle Image Velocimetry test when axial and permeating flow all exist in the separator. After vortices formed, if the rotate speed of inner cylinder is faster, the radial, axial and azimuthal velocity of flow near the cortical core increase. If the annular pressure is higher, the radial and axial velocity of flow near the cortical core of meridional plane don't increase, but the velocities achieve...