Tubular Membrane Microfiltration Process Intensification And Hydraulic Characteristics Study

Microfiltration technology is an important component of the membrane separation field, it has been widely used in dindustrial production process. Membrane fouling is the main problem that reduce the operation efficiency and membrane separation performance. Installing the turbulence promoters into the membrane module can change the hydraulic flow characteristics in flow channel, mitigate the deposition of particles on membrane surface, thereby inhibit the formation of fouling. It is widely regarded as one of the most effective method for improving the separation performance and intensify the microfiltration process performance.In this paper, the pilot-scale crossflow microfiltration experimental stage (maximum handing capacity is16m3/h) was set up, the diatomaceous earth and yeast suspension crossflow microfiltration experiment was conducted respectively. The tubulence promoter was installed in the membrane module, its strengthening effect on the microfiltration process was verified combined experiments and numerical simulations.(1) The diatomaceous and yeast suspension microfiltration experiment was carried out using the experimental platform respectively. The effect of operating parameters (flow rate, transmembrane pressure, suspension concentration) and physical parameters (membrane pore size, particle size and distribution) on microfiltration performance was investigated, the optimum operating procedure was discovered. The experiment result reveals that the maximum flux which is535.54L/m2·h and the minimum filtration resistance were obtained when the flow rate is6m3/h. The optimum microfiltration performance was obtained when transmembrane pressure ranges from0.10MPa to0.12MPa. The membrane pore size and particle size distribution have significant impact on microfiltration performance.(2) A seious of baffles were installed in the tubular membrane module, the effect of baffle structure parameters (radius, angle of the fan baffle) and baffle arrangement (baffle spacing and the baffle arrangement) on microfiltration process intensification and the mass transfer efficiency was studied. The experiment results reaveal that the permeat flux was higher than the membrane module without baffles, the filtration resistance was smaller. Taking the intensification efficiency and energy loss into consideration, the optimum turbulence promoter form was determined.(3) The three-dimensional numerical model was established with the method of computational fluid dynamics software Fluent, the turbulent flow was simulated. The effect of baffle structure parameters (baffle radium and fan-angle) and baffle arrangement (baffle spacing, arrangement phase angle) on hydraulic characteristics within the membrane module was studied. The simulation results show that the presence of baffles has greatly enhanced the shear stress and turbulent kinetic energy on membrane surface and strengthened the microfiltration process performance significantly. Considering the intensification effect and the additional energy loss, the optimum turbulence promoter structural parameters and arrangement were discovered.The simulation results and experimental results achieved better consistency. The results in this paper could provide the necessary data for optimizing the membrane structure in the future. The research on microfiltration experiment procedure using the pilot scale experiment platform was conducted and the experiment results provide the necessary base data for microfiltration process enhancement equipment for industrial amplifier design.