关键词: 移动床过滤器, 逆流式, 除尘效率, 压降

Abstract: Granular bed filtration is one of the most promising high-temperature filtration technologies and has good prospects for application in environmental protection or in industrial production. Compared to the fixed bed, the moving bed filters with the stability for long-cycle operation are more in line with practical requirements. The influences of the superficial gas velocity and the regeneration gas velocity on the gas-solid countercurrent moving bed filter are investigated by cold model experiment. Under the dust-free operating conditions, it is found that the bed pressure drop increased parabolically with the superficial gas velocity. It can also be estimated by the modified Ergun formula. Under the operating condition of dust-leaden, on the other hand, it is proved that the variation trend of dust removal efficiency is the same as that of gas residence time. It is positively correlated with the regeneration gas velocity. The gas residence time is mainly influenced by the superficial gas velocity and the accumulation of dust in the filter, which varies as the experiment proceeds. The pressure drop of the bed is positively correlated with the gas velocity whereas is negatively correlated with the gas regeneration velocity. The experimental results show that the dust collection efficiency of this equipment is fairly high. When the superficial gas velocity ranges from 0.122 m/s to 0.305 m/s, with the inlet concentration of 8.175 g/m3, the dust removal efficiency is generally higher than 98.0%. The bed pressure drop always maintains dynamic equilibrium within a certain range, and the maximum rise does not exceed ±0.05 kPa. The fraction efficiency for the fine dusts smaller than 13 μm also achieves 99.99%.

Key words: moving bed filter, countercurrent, efficiency of dust collection, pressure drop