The effects of superficial gas velocity

filter media flow rate and dust content in gas on collection efficiency of the cross-flow moving granular bed filter were investigated experimentally and the effect of dust deposition in the granular bed was also discussed. The results showed that a lower superficial gas velocity and moving speed of pellets could improve collection efficiency. The deposition of dust in the granular bed could affect dust removal efficiency. Less dust deposit could improve the efficiency obviously

while such improvement could become insignificant due to reentrainment of the deposited particles. A mathematical model was established to simulate the effect of dust deposit on collecting efficiency and the non-uniform deposition of dust in the granular bed on the basis of the constricted-tube concept. The model test showed that the model prediction was in good agreement with the experimental data for operating gas velocity from 0.1 m8226;s-1 to 0.3 m8226;s-1.Based on the model

the analysis on the relationship of collection efficiency with the length of the granular bed and the distribution of dust deposit was conducted.