Simplified CFD approach of a hollow fiber ultrafiltration system

Coagulation and ultrafiltration: Understanding of the key parameters of the hybrid process

“…A maximum shear stress of 10 Pa is reached near the membrane surface, but does not represent the average value of shear stress that a floc can be subjected to when it enters into the fibre. A shear stress between 1 and 2 Pa seems to be a more reasonable average value [16]. The Taylor-Couette reactor A reached a shear stress of 1.5 Pa at its maximum rotating speed of 104.7198 × 10 −1 rad/s (100 rpm).…”

“…Their external dimensions are the same, but they present different gap width and rotating speed, which enable different shear stresses to be examined. The profile of shear stress in hollow fibres was determined by numerical simulation [16]. In the reactor A, coagulation was performed at the maximum rotating speed, creating a shear stress of 1.5 Pa, which corresponds to the average value of shear stress in the hollow fibre.…”

Predicting optimal back-shock times in ultrafiltration hollow fiber modules II: Effect of inlet flow and concentration dependent viscosity

“…Mathematical modeling and computational fluid dynamics are increasingly being used to gain understanding of cause and effect in membrane filtration [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33]. Of these the following papers concern back-shocking [28][29][30][31][32][33].…”

Development and analysis of an integral fluidodynamic model in hollow fibre for different operational modes

“…A 3-D finite model of the blood-dialysate interface over the complete length of the dialyser was developed. Also, Ghidossi et al [17] numerically investigated the flow profile in a HF by CFD as a function of the working conditions and the membrane geometry. Also [8], [49], and [50] developed models with CFD for HF.…”

“…Several researchers have used empirical equations to explain the pressure drop in the lumen of the fibres [17] but generally the pressure in the lumen compartment is assumed to drop along the fibre length according to the Hagen-Poiseuille equation [18][19][20]. Greater controversy exits in explaining the pressure profile in the shell.…”