Three-dimensional numerical simulation and structural optimization of filtration performance of pleated cylindrical metal fiber filter

Abstract

Cylindrical metal fiber filters have the advantages of high-temperature resistance, radiation resistance, and large filtration area. They have been widely used in the filtration and emission systems of nuclear power plants and are mainly used to remove radioactive aerosols in the containment under severe accidents. To optimize the filter structure, this research uses the numerical calculation method to verify the flat metal fiber's flow resistance and filtration efficiency. Based on the verification results, the performance of pleated cylindrical filter element is calculated (including pressure distribution, velocity distribution and efficiency distribution, etc.), the flow resistance and filtration efficiency of the cylindrical structure are analyzed, and the performance of the cylindrical filter is compared with that of the flat filter. The comparison found that due to the uneven flow distribution in the vertical direction of the cylindrical structure, the filtration efficiency will be lost after the flat filter is processed into a filter cartridge. Based on the research results, the flow resistance and filtration efficiency of filters of different sizes are also calculated, and the structural size of the cylindrical filter element is optimized. The results show that increasing the outer diameter of the filter element and reducing the height of the filter element can reduce the resistance, improve the filtration efficiency, and flatten the distribution of velocity and efficiency. For a filter element with a height of 500 mm, it is recommended to set the outer diameter to 175 mm. The research results can provide a design reference for engineering filter elements processing and manufacturing.