Study on the separation characteristics of different flow patterns in rotary tubular micro-filtration membrane separators

The flow pattern between concentric cylinders of micro-filtration membrane separators and the inner cylinder rotating can transform from one kind of pattern to another at different flow conditions when there are axial flow and radial flow. The discrepancy between the inputted electromagnetic rotational speed and the rotational speed of the electromotor is a token of the flow pattern. Under the constant pressure operation condition, the resistance of membrane separation can be divided into undefiled resistance, irreversible resistance and reversible resistance. The first two resistances can be a constant in very short time, and the reversible resistance is a function of rotation under a regime of certain flow pattern. The flow patterns are dividedinto four patterns: Couette-Poiseuille flow, random laminar wavy vortices, turbulent wavy vortices and turbulent vortices that have distinct influence on the filtration flux and the membrane separation resistance shown by the experiment. Membrane separation characteri