The Numerical Simulation Of Temperature Field And Particle Concentration Distribution In Bag Filters

The flow field and temperature distribution in the bag filter equipment directly affect the dust removal efficiency, energy consumption and running safety of the equipments. But the real time measurement of internal flow field is difficult since the complex structure and strict conditions of sealing. Using the CFD simulation software to predict and analyze the internal flow pattern is the best way to achieve it now. To predict the corresponding physical prototype, the paper study big bag filter in engineering practice and its digital prototype model with CFD simulation technology.The related research subject of comprehensive test and validation platform for digital prototype of bag filter was supported by the Scientific Research Fund of Sinoma Group. The major tasks of this paper were as follows:First, in order to improve the internal flow field of bag filter, flow guiding device was introduced into the hopper. Since the influence of the it in temperature to the inside of filter is unknown, the paper will give a evaluation of the effectiveness of the flow guiding device with comparing the temperature distribution inside of before and after setting. At the same time, it will also discuss the influence of filtration velocity to temperature field.Secondly, aiming at the problem that the concentration field cloud image is not obvious enough since the content of particles is low, the paper give one more scientific and effective description of the dust concentration distribution by using the Euler Lagrange model. The paper will explore the effect of length of filter bag and the inlet velocity of the room entrance on dust distribution, and compare with documents.Last, the relationship between the concentration of the distribution and the velocity of the filtered gas flow as well as the relationship between concentration and thickness of cake, was reseacched through the calculation of the flow field in the model by gas-solid two-phase flow method. The evaluation of the function of digital prototype from the point of concentration field is came true.The simulation results show that temperature and dust concentration at the bottom of the bag are higher. Decrease of temperature will with the increase of heightuntil the flow achieve a place with a distance of 1.5m to the horizontal plate. The temperature and particle concentration near the wall are higher than where there is a high bag dense. The temperature and powder growth rate of bag near the wall are significantly faster than which in the other positions when filtration velocity increased.The flow of the near wall region is reduced with flow guiding device, which is to regulate the internal temperature field. And the guiding plate has the best effect.