Particles Separation and Tracks in a Hydrocyclone

100學年度研究獎補助論文[[abstract]]Hydrocyclone separation technique recently has been used in an increasing number of applications. Reynolds Stress Turbulence Model (RSM) and Discrete Phase Model (DPM) were employed in Computational Fluid Dynamics (CFD) 3D simulation to draw the motion trace of single particle of different particle size and density in hydrocyclone separator. It is known that, smaller size particles flow out from overflow, larger size particles flow out from underflow, and there is a characteristic size of particles having longer residence time in hydrocyclone separator. Particle size influences separation efficiency more significantly than particle density. Simulation of particle cluster separation efficiency in hydrocyclone separator has some discrepancy from experimental result. It is because air core influence is not considered in this study.[[notice]]補正完畢[[incitationindex]]EI[[booktype]]紙

Tubular membrane filtration with a side stream and its intermittent backwash operation

[[abstract]]The tubular membrane filtration system is widely applied to solid-liquid separation processes. Any improvements to the filtration module would increase separation efficiency, thus reducing operating costs. In this experiment, PMMA powder with an average particle diameter of 0.8 µm was filtered by a ceramic tubular membrane with an average pore size of 0.2 µm, and the impacts of the operating variables, such as suspension concentration, the filtration pressure, and the crossflow velocity on the permeate flux were discussed. In order to understand the increased permeate flux, the proposed module is comparable to the tubular membrane filtration module, but with an additional side stream under the same filtration mass flow rate. In addition, variations of shear force on the membrane surface are analyzed by CFD simulation, and the influence of backwash operations on the permeate flux is discussed. The results show that the side stream membrane filtration increased the shear force on the membrane surface, reduced fouling on the membrane surface, and increased the permeate flux. Furthermore, a backwash operation with a side stream flow channel could effectively clean the particles deposited in the module, thus, increasing the permeate flux.[[journaltype]]國外[[incitationindex]]SCI[[booktype]]電子版[[countrycodes]]US

Increasing Filtrate Flux of Cross-Flow Filtration with Side Stream

[[abstract]]In this study, we use simulations to calculate the velocity fields of cross-flow filtration, overall filtration resistance, and shear force distribution on the membrane surface and then compare the results with experimental results. Also, side stream ideas are used in this study in hopes of changing the flow strength conditions in the filtration chamber to increase shear force on the membrane surface under identical energy loss in order to achieve the effect of increasing filtrate flux. The simulation and experimental results show that this cross-flow filtration with side stream can effectively increase the filtrate flux and lengthen the fouling time.[[incitationindex]]SCI[[incitationindex]]EI[[booktype]]紙

A Novel Three-outlet Hydrocyclone

[[abstract]]Hydrocyclone separators are widely employed in industrial processes, such as papermaking, medical and pharmaceutical, and bioseparation processes. Although hydrocyclones are very simple and with low cost, their separation efficiencies are poor compared to others separation technologies. This novel hydrocyclone utilized tubular ceramic membrane inside its body and allow it to achieve a much clearer supernatant as well as its usual capabilities of classifications of particles. In solar energy process, it has great potential to recover silicon, silicon carbide, and polyethylene glycol on line. In addition, this innovation can recover both precious solid particles and precious liquid simultaneously, which is highly valuable for some applications.[[conferencedate]]20150428-30[[conferencelocation]]C

Simulation of resistance of cross-flow microfiltration and force analysis on membrane surface

[[abstract]]The major factors influencing cake formation and the overall filtration resistance were the hydrodynamic forces exerted on the membrane. Therefore, the filtration rate increased with the increase of the cross-flow velocity and filtration pressure under a wide range of conditions. In this work the cross-flow microfiltration was simulated by water flow through a porous medium. The bulk flow and flow in porous medium were governed by Navier-Stokes and Darcy equations. The overall resistance of filtration and hydrodynamic shear force exerted on the membrane surface were calculated and integrated. The shear force analysis on the membrane surface is a tool for decaying fouling rate on the membrane and improving the efficiency of the cross-flow microfiltration. This CFD-aided design could help to effectively increase the permeate flux, reduce the fouling on the membrane and extend the washing cycle during filtration.[[incitationindex]]SCI[[incitationindex]]EI[[booktype]]紙

Effect of Overflow Depth of a Hydrocyclone on Particle Separation

99學年度吳容銘研究獎補助論文[[abstract]]In recent years, the hydrocyclone separation technique has been used in an increasing number of applications. Computational fluid dynamics (CFD) is also feasible for estimating the hydrocyclone performance at various operating conditions, as demonstrated in previous works. This study discusses the impact of overflow depth on separation efficiency through simulation and experiment. Both results showed that separation efficiency was optimal when the overflow depth was above the middle section of the cylindrical portion of a hydrocyclone.[[incitationindex]]SCI[[incitationindex]]EI[[booktype]]紙本[[booktype]]電子