Filtration and membrane separation processes

Open separators bulk flow parallel to force and CSTSs 

The quantity NsVs is also equal to the solvent velocity Vj (cm/s) through the filter (compare equations (3.4.60d-f) and (3.4.85)). At any instant of time, both the filter and the cake on top of it provide resistances to flow R for the filter and Rc for the cake. If the pressure drops through the membrane/filter and the cake are, respectively, APm and APo then 

Since the surface area of a particle in the cake per unit particle volume, a, is related to dp by 

If the membrane/filter has Np pores, each of size tp, per unit area, and the membrane porosity is e, then 

Sometimes, such a cylindrical pore based representation is avoided instead membrane porosity, and pore surface area/membrane volume, s are used. For c indrical pores 

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