摘要
对于内筒旋转的同心圆筒微滤膜分离器,环隙间流体的流动在周向流、轴向流和渗透流的综合影响下会发生流型的转化和过渡;提出用三相异步电动机的输入电磁转速与电动机的实际转速之差的变化情况来表征流型的转化和过渡;用渗透通量的倒数在恒压操作过程中,将过程阻力分解成洁净膜阻力、不可逆膜污染阻力和可逆膜污染浓差极化阻力三部分,洁净膜阻力和不可逆膜污染阻力在很短的试验操作条件下可以视为常数,从而阻力随转速的变化在加上不同的常数后,可以表征出不同流型下的膜分离特性。在试验基础上,将流型划分为库特层流、随机层流涡流、紊流波涡流和完全紊流等四种类型,并分别讨论了这四种流型所产生的膜分离特性。试验表明,完全紊流区的可逆膜污染浓差极化阻力最小。
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 be 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.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2004年第6期65-70,共6页
Journal of Mechanical Engineering
基金
教育部高等学校博士学科点专项基金(200061016)
关键词
旋转管式膜
微滤
流型
过滤阻力
渗透通量
涡流
Rotary tubular membrane separator
Microfiltration
Flow pattern
Filtration resistance
Filtration flux
Vortices flow
