Abstract: In industries such as mining and metallurgy,metal fiber filter are widely used due to their small size and ability to operate at higher filtration velocity. However,under high filtration velocity conditions,the internal flow field of the metal fiber filter has problems such as disordered filtration airflow and uneven distribution of flow field,leading to dust accumulation at the top of the filter bag and ineffective cleaning,which limits the stable operation and advantages of the metal fiber filter. The fluid dynamics software CFD-Fluent was used to numerically simulate the flow field in the dust collector with high filtration velocity. The results indicated that when the inlet air velocity increased from 4. 5 m / s to 8. 9 m / s,the increase in the processing air volume at the upper part of the filter bag increased from 1. 97% to 4. 76%. The distribution uniformity of flow field is poor. Accordingly,the type Ⅰ deflector ( 2 rectangular plates,aligned with the filter bag) and type Ⅱ deflector ( 3 rectangular plates,aligned with the filter bag at intervals) were designed and manufactured,and each deflector model is placed at 0°,10° and 20° with the horizontal plane. The uniformity of flow field was evaluated by comparing and analyzing the flow characteristics,the surface velocity of filter bag and the flow distribution coefficient under 6 optimization schemes. The results show that: ① The optimization effect of the installation model of type Ⅱ deflector is better than that of type Ⅰ ,with the increase of the installation angle,the impact of air flow on the bottom of the filter bag increases,and the optimization effect gradually weakens. ② Type Ⅱ -0 deflector can reduce the standard deviation of the average velocity on the surface of the filter bag to 0. 209 8,a decrease of 47. 4%,and the uneven amplitude of the comprehensive flow field to 0. 003 4,a decrease of 69. 2%. The above results provide a theoretical basis for the structural optimization design of metal fiber filters when treating flue gas at high filtration velocity.

Key words: metal fiber filter,tigh filtration velocity,numerical simulation,flow field optimization