Investigation on flow field characteristics of bag filter based on CFD simulation: effects of processing air volume and dust accumulation degree

To investigate on the flow field characteristics of a box-type bag filter device during the whole life cycle. This study established a CFD numerical calculation model of the dust collector device and verified the effectiveness in combination with the experimental results. Subsequently, numerical analysis was conducted under the consideration of the dust accumulation degree and the processing air volume. The study shows that with the increase of operating time, the dust accumulation degree on the filter bag increases, the surface permeability coefficient decreases, and it can be expressed as a negative exponential function of the operating time. As the dust accumulation degree increases, the uniformity of flow field distribution decreases, and the root mean square error of the device increases, while the increase in the processing air volume has no significant effect on the flow field. The total pressure drop of the device is mainly composed of the viscous resistance term caused and the inertial resistance term. The viscous resistance term is inversely proportional to the surface permeability coefficient and is proportional to processing air volume, while the inertial resistance term is proportional to the square of the processing air volume. Based on the numerical analysis results, this study established a empirical formula to describe the relationship between the pressure drop, filter bag resistance and processing air volume.