Numerical simulation study on the filtration performance of metal fiber filters

Abstract

As an essential component of the ventilation system of nuclear facilities, filters have significant filtration performance for the safety of the environment and personnel. The metal fiber filter has excellent temperature resistance and can still maintain good filtration performance under fire conditions. In the filter design process, it is usually necessary to fold the metal fibrous fabric into a pleated structure to increase the filtration area and improve performance. A numerical simulation method is carried out on the filtration performance of the metal fiber filter, and the complex stacking structure inside the metal fibrous fabric is simulated using the porous zone. It is developed by combining the flow resistance and particle collection efficiency calculation program based on the structural parameters of the fibrous fabric with FLUENT software. The accuracy of the developed simulation method is validated with experimental data. The filtration performance of metal fiber pleated filters is further studied by this method. The results indicate that the influence of the pleat geometries on the collection efficiency of filters can be ignored. Brownian diffusion and interception play a dominant role in the filtration process. As the filtration velocity increases, the Brownian diffusion effect of particles is suppressed, this is the main reason for the decrease in filtration efficiency. With the same geometries, the resistance of rectangular pleats is always smaller than that of triangular pleats. With the same geometries, rectangular pleats have more uniform flow distribution than triangular pleats.