移动颗粒床除尘器的除尘性能

为进一步了解移动颗粒床除尘器的除尘性能，首先解决了除尘器中容易出现的流动静止区域的消除问题，并实验研究了除尘效率及压降与表观过滤风速和滤料质量流率之间的关系，结果表明当表观过滤风速为0.3 m·s-1，滤料质量流率为300 g·min-1时，除尘效率高达99.8%，压降最大还不及180 Pa。另外，通过数值仿真得到了滤料床层内部气体的流场分布以及灰尘粒子在床层中的运行轨迹，发现除尘器结构部件对气体流场分布以及灰尘粒子轨迹有重要影响。对仿真过程中逃逸出滤料床层的灰尘粒子进行统计，并与实验数据相比较，验证了尘饼对增强细微灰尘捕集能力的重要性。

Dust removal performance of moving granular bed filter

In order to learn more about the dust-removal performance of moving granular bed filters,a solution to diminish the stagnant zone that often exists in moving granular bed filters was studied. A series of experiments were conducted to demonstrate the collection efficiency and pressure drop at different superficial velocities and mass flow rates of filter granules. The experimental results show that the best collection efficiency can be achieved by using a superficial velocity of 0.3 m·s-1 and mass flow of 300 g·min-1. The collection efficiency can be as high as 99.8%,and the pressure drop remains below 180 Pa. In addition,a simulation model was established to determine the gas distribution and dust particle trajectories in the granular bed. We found that the structure of the filter has an important influence on the gas distribution and dust particle trajectories. By comparing the statistics of dust particles that escaped from the granular bed with experimental data,the importance of dust cake in enhancing the collection efficiency of fine particles is demonstrated.