Research On Separation Mechanism Of Filtering Hydrocyclone

The filtering hydrocyclone is a new-type solid-liquid separation device with multiple mechanisms and functions. For its integration of rotating flow and filtration, the device has not only the advantages of conventional hydrocyclones which presented no moving parts and operatered simplely, but also possessed the filtering ability which was expected to improve the separation performance of hydrocyclone and enlarge its application field.In this paper, based on the structure of the axial-flow hydrocyclone, a series of filtering hydrocyclones were designed and manufactured. The research of separation performance was carried out. The important structures like cylinder length and conical angle were chosen through experiments. Combined with theory analysis and experimental data, the reasonable structure parameters were shorter cylinder and smaller conical angle. The filtering hydrocyclone made of the reasonable structure parameters was acted as a standard device. Meanwhile, the effect of flow rate, underflow ratio and concentration to separation efficiency, pressure drop and filtration flux was analyzed by experimental data. Some conclusions were determined: The increase of slurry concentration made filtring flux and separation efficiency was first increased and then decreased, the trendency of pressure drop increased increased slow and gradually stabilised; The increase of flow rate made separation efficiency increased, pressure drop reduced and filtration flow reduced; The increase of entry median size made separation efficiency increased obviously, the increase of material viscosity made separation efficiency reduced, but the material nature influenced pressure drop little; The increase of filtering medium aperture made separation efficiency increased and pressure drop reduced, separation efficiency changed more obviously than pressure drop, the same conclusions were determined in the cylinder and consistent cone; Relative to filtering cone, filtering cylinder was the main reason to reduce fine solids content in underflow, with the increase of the filtering aperture, the content of fine particles was reduced. Based On experimental results, the improvement structure of changing filtering cylinder into entity structure was put forward, and optimized length of the cylinder was 60mm. Compared filtering hydrocyclones with a hydrocyclone with the same? structure parameters, conclusions were that separation efficiency and pressure drop of filtering hydrocyclones were slightly lower than a hydrocyclone, and reduced with the increase of aperture. A performance evaluation method using efficiency-pressure drop ratio and comprehensive separation index was presented according to two unique clear flows of filtering hydrocyclones. By this method, the conclusion was that the performance of small aperture's filtering hydrocyclone was better than that of the hydrocyclone. Comparative experimental results showed that filtering hydrocyclone can effectively reduce energy consumption and enhance production capacity, and can reach a good separation effect in higher entry flux.The model of a satandard structure was made firstly, then meshing and confirmed the boundary conditions. Reynolds Stress mode (RSM) was used to calculated the flow in the axial guide-vane filtering hydrocyclone. The results showed that there were the attenuation of velocity and pressure in the cylinder zone. Analyzed and compared the reasons and composition of pressure drop, a new-type filtering hydrocyclone was proposed.Then by force analysis ofparticel in filtering hydrocyclone, the minimum diameter that can be seperated and filteration velocity were concluded, and the regressive model formulas of classification efficiency and volumetric capacity were proposed.Researches in this paper may make the foundation for further development and application and has great theoretical and engineering significance for development the new-type soild-liquid separator and consummation of separation theory.