Numerical Simulation And Optimization Of Internal Flow Field Inside A Upside-entrainment Bag Filter

Nowadays, the fine particulate are the main factors which associated with adverse health effects and polluted the atmospheric environment. With the more and more stringent standards in China, as a kind of dust collector which have efficient collection efficiency, bag filter will have a more broad application prospects.Based on FLUENT software package, the flow field in a large and upside-entrainment bag filter of a company’s experiment platform was simulated and optimized. This work consisted of four parts. At first, the inner flow field of the bag filter was simulated, we found that the airflow distribution is uneven in the bag room,and bags close to the intake chamber were easily damaged, while the effects of different diameters of the bag on filter performance needed further exploration.Secondly, the different effects on the number of bags in the baghouse to flow field were investigated. Flow distribution coefficient, maximum flow uneven amplitude,airflow pathline, surface velocity distribution and pressure drop were regarded as important indexes to study the pattern.The results showed that the flow distribution was most uniform and the pressure drop was acceptable in the case of 76 bags.Under the same filtration rate, the pressure drop increased with the increase of the number of bags, namely the turn of pressure drop was as follows 92>88>84>76>72. Furthermore,the effective filtration area of 76 bags was more than 72 bags.So, 76 bags was the optimal number of bag filter. Thirdly, the effects of different diameter(includingΦ150mm and Φ130mm) on the baghouse inner flow field were studied. Flow distribution coefficient, the velocity and pressure distribution on different section(including Z=3300mm, 5800mm) were discussed. It was found that after using the same type of bag diameter, the rows of bag had a more balanced air distribution,and the velocity and pressure in the baghouse section distributed more evenly. Finally,the gas-solid two-phase flow in upside-entrainment bag filter was simulated. The particle trajectories from 0s to 5s were analyzed, and the particle concentration on different sections in baghouse was explored. The results showed that, most of the particles had a downward movement along with the pre-set buffer area, then advancing to the exhaust port side. The upside-entrainment bag filter had a good use of particle weight, which made the pressure loss decrease in bag filter. And this inevitably contributed to the result of the bag near the inlet chamber loading heavierparticles, while the bag close to the exhaust port treating a fewer particles. These results could provide a guideline for the design and optimization of upside-entrainment bag filter in engineering applications.