Study On The Filtration Process Of The New Dynamic Cross-flow Plate And Frame Filter Press

Plate and frame filter press is a filtering device, widely used in the solid-liquid separation process. With the rapid development of industrialization, the structure of plate and frame filter press is also constantly improved in order to meet the requirement of progress. By adopting diagonal tangential feeding, a new kind of dynamic cross-flow plate and frame filter press can enhance the filtration rate and improve the filtering efficiency.Computational fluid dynamics method and experimental research are used in the paper to study the filtration process of the new dynamic cross-flow plate and frame filter press. The experimental results show the flow morphology within the filter chamber under different feeding ways, in the meantime, the filtration rate of the new diagonal tangential feeding compared with traditional central feeding are also measured and analyzed. The results show that the filtering effect of tangential feeding has an advantage over traditional central feeding.The paper establishes a3D geometry model of the new dynamic cross-flow plate and frame filter press by the software FLUENT based on the theory of computational fluid dynamics. Using standard k-ε model, Euler-Euler multiphase flow model and porous model to simulate the filtration process. With the established model, the simulation obtains fluid flow velocity distribution, pressure distribution, solid content distribution and turbulence structure within the filter chamber. The numerical simulation results of the filtration rate variation tendency (average error is within15%), the filter time, the particle trajectory, the filter cake formation laws within the filter chamber are basically the same as the experimental results, which proves accuracy and feasibility of the numerical model. Using the validated numerical model, the influence of different parameters (filter medium porosity, particle diameter, inlet pressure and suspension concentration) on filtering effect are also calculated and analyzed. The results show that, as the filter medium porosity increases, the filtration rate also increases, so does the the filter liquid solid content. With the particle diameter increasing, the filtration rate become large, while the variation of filter cake moisture content is contrast. As the filtration pressure increases, the filtration rate also increases, so does the release velocity of filtration rate, while the filter cake moisture content decreases. As the feed concentration increases, the filtration rate decreases, so does the release velocity of the filtration rate, while the variation of the time to reach steady state, solid content of the filter liquid and cake moisture content are contrast.Documents about the numerical simulation of filtration process with high concentration have not been published, the study of this paper is a initial attempt to simulate the filtration process of the new dynamic cross-flow plate and frame filter press. The research results can provide a reference and guidance for the numerical simulation of the filtration process and optimization design.