CFD simulations have been used to determine mass transfer coefficients and power consumption of commercial net spacers. The simulations show transversal and longitudinal vortices, vortex shedding and instationary flow behavior leading to the enhanced mass transfer in spacer filled-channels compared to empty channels. The results of the simulations were validated with experiments and compared wi...

An optimal design strategy for spiral-wound membrane networks based on an approximate permeator model and a mixedinteger nonlinear programming (MINLP) solution strategy is proposed. A general permeator system superstructure is used to embed a very large number of possible network con®gurations. The superstructure allows the development of a MINLP design strategy which simultaneously optimizes t...

the effect of membrane molecular weight cut off (mwco) at three levels (10, 20 & 50 kd) on dynamic behavior of permeate flux (jp), hydraulic resistances (total hydraulic resistance, rt; reversible fouling resistance, rrf; irreversible fouling resistance, rif and membrane hydraulic resistance, rm) and milk solutes rejection (protein, rp; fat, rf; lactose, rl; minerals, rm and total solids, r...

The effect of membrane molecular weight cut off (MWCO) at three levels (10, 20 & 50 kD) on dynamic behavior of permeate flux (JP), hydraulic resistances (total hydraulic resistance, RT; reversible fouling resistance, Rrf; irreversible fouling resistance, Rif and membrane hydraulic resistance, Rm) and milk solutes rejection (protein, R<s...

A reliable dynamic simulator (based on a sound process model) is highly desirable for optimizing the performance of individual membrane modules and of entire desalination plants. This paper reports on progress toward development of a comprehensive model of the complicated physical-chemical processes occurring in spiral wound membrane (SWM) modules, that accounts for the...

The membrane architecture of the cytoplasmic tubules in lamprey chloride cells has been studied by electron microscopy using thin-section and freeze-fracture techniques. The chloride cell of lampreys (Lampetra japonica, Petromyzon marinus) is largely occupied with a continuous network of cytoplasmic tubules, which are derived from the invagination of the basolateral plasma membrane. The lumenal...

in this report, experimental investigation of waste water treatment by reverse osmosis to enable its reuse in cooling tower is presented. a polyamide spiral wound ro membrane followed by three filters as ro pretreatment (two activated carbon and one cartridge filter) and samples of tehran refinery treated waste water have been used. the effect of operating conditions such as pressure difference...

In this report, experimental investigation of waste water treatment by reverse osmosis to enable its reuse in cooling tower is presented. A polyamide spiral wound RO membrane followed by three filters as RO pretreatment (two activated carbon and one cartridge filter) and samples of Tehran refinery treated waste water have been used. The effect of operating conditions such as pressure differ...