Investigating the Dialysis Treatment Using Hollow Fiber Membrane: A New Approach by CFD

Abstract

Due to the increase in the number of people affected by chronic renal failure, the demand for hemodialysis treatment has increased considerably over the years. In this sense, theoretical and experimental studies to improve the equipment (hemodialyzer) are extremely important, due to their potential impact on the patient’s life quality undergoing treatment. To contribute to this research line, this work aims to study the fluid behavior inside a hollow fiber dialyzer using computational fluid dynamics. In that new approach, the blood is considered as multiphase fluid and the membrane as an extra flow resistance in the porous region (momentum sink). The numerical study of the hemodialysis process was based on the development of a mathematical model that allowed analyzing the performance of the system using Ansys® Fluent software. The predicted results were compared with results reported in the literature and a good concordance was obtained. The simulation results showed that the proposed model can predict the fluid behavior inside the hollow fiber membrane adequately. In addition, it was found that the clearance decreases with increasing radial viscous resistance, with greater permeations in the vicinity of the lumen inlet region, as well as the emergence of the retrofiltration phenomenon, characteristic of this type of process. Herein, velocity, pressure, and volumetric fraction fields are presented and analyzed.

Numerical Simulation of Mass Transfer in Hollow Fiber Membrane Module for Membrane-Based Artificial Organs

“…Consequently, the convective transmembrane flux exhibits a linear distribution, as described in Equation (9). This result is consistent with the findings of Magalhaes et al [ 35 ]. As shown in Figure 9 , at x ≈ 0~0.175 m, the pressure in the tube-side region is higher than that in the shell-side region.…”

“…The clearance rate of the hollow fiber membrane module can be determined by calculating the average concentration of solutes at the inlet and outlet of the tube-side. The calculation formula of the clearance rate of the hollow fiber membrane module is as below [ 35 ]: where is the flow rate at the tube-side inlet, is the flow rate at the tube-side outlet, is the average concentration of solute at the tube-side inlet, and is the average concentration of solute at the tube-side outlet.…”

“…They also pointed out that the mass transfer is mainly influenced by membrane type and operating conditions [ 18 ]. To study urea transport in the hollow fiber membrane, Magalhaes et al proposed a new CFD model in which blood was treated as a multiphase fluid and the hollow fiber membrane was considered as an additional viscous resistance, and they obtained a new method for calculating clearance rate by changing the viscous resistance [ 35 ]. The numerical results in Magalhaes et al were in agreement with experimental results of Liao et al [ 36 ], but the diffusive solute transport was not included in the numerical model.…”

Study of CFD-DEM on the Impact of the Rolling Friction Coefficient on Deposition of Lignin Particles in a Single Ceramic Membrane Pore

“…where, F drag is the drag force of the particle, N; A is the projection area of the particle, m 2 ; C D refers to the drag coefficient, which depends on the Reynolds number Re, and can be calculated by Equation ( 11) [37].…”