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Abstract:
The flow pattern between concentric cylinders of micro-filtration
membrane separators with the inner cylinder rotating can transform from
one kinds 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 a
process of very short time, and the reversible resistance is a function
of rotation under a regime of certain flow pattern. The flow patterns
are divided into 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 characteristics
in each flow pattern is discoursed respectively based on the separation
experiment with quartz sand suspension，and turbulent vortices flow
patter is at the best for rotary tubular membrane separator.
Key words:
Rotary tubular membrane separator Microfiltration Flow pattern
Filtration resistance Filtration flux Vortices flow
CLC No: TQ051.8
教育部高等学校博士学科点专项基金资助项目(200061016). Received 20030912, received in revised
form 20031230
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