气固逆流式移动床过滤器的实验研究

Experimental study on a gas-solid counter-flow moving bed filter

为探究操作条件对气固逆流式移动床过滤器过滤性能的影响,通过大型冷模实验,考察了气固逆流式移动床过滤器的捕集颗粒循环强度、入口粉尘浓度、表观气速及入口粉尘粒径对装备性能的影响。实验结果表明,表观气速是影响床层压降的主要因素,表现出正相关的趋势。捕集颗粒循环强度、入口粉尘浓度、粉尘粒径的改变对床层压降影响较小。捕集颗粒循环强度和入口粉尘浓度的增加使压降增加。而粉尘粒径与床层压降间的关系随时间变化,开始时粉尘粒径与压降呈正相关,但当装置运行至平稳阶段则趋于降低。装备的除尘效率与入口粉尘浓度及颗粒循环强度正相关,与粉尘粒径及表观气速负相关。但粉尘粒径越小过滤效率越高的趋势受装置内滤饼的影响,仅在粉尘中位粒径10μm以上,且入口粉尘质量浓度在0~32 g·m^(-3)出现。移动床过滤器保持稳定床层压降的同时,具有较高的除尘效率。在颗粒循环强度0.3119 kg·s^(-1),16.5~32.7 g·m^(-3)入口粉尘浓度条件下,除尘效率可达99%;且对细微(13μm以下)粉尘的粒级效率接近99.9%。

In order to investigate the influence of operating conditions on the filtration performance of gas-solid countercurrent moving bed filters.Effects of collecting particle circulation flux,inlet dust concentration,superficial gas velocity and inlet dust particle size on the filtration performance of a gas-solid counter-flow moving bed filter were investigated by large cold-mode experiments.The experimental results show that the superficial gas velocity is the main factor determining the filter pressure drop with a positive correlation tendency.The variations of collecting particle circulation flux,inlet dust concentration and dust particle size have less effects on the filter pressure drop.The particle flux and inlet dust concentration present a positive correlation with the pressure drop.The effects of particle size varies with time.The particle size of the dust is positively correlated to the pressure drop at beginning whereas it decreases in the stable period.The dust removal efficiency of the equipment shows a positive correlation with the inlet dust concentration and the particle circulation flux,while the opposite is true with the dust particle size and the superficial gas velocity.The trend of higher filtration efficiency with smaller dust particle size is affected by filtration cake in the filter,which happens at the median dust diameter above 10μm and the inlet dust concentration from 0 to 32 g×m^(-3).The filter has high dust removal efficiency with stable pressure drop.Under the conditions of particle circulation flux 0.3119 kg×s^(-1)and inlet dust concentration 16.5-32.7 g×m^(-3),