Abstract

ABSTRACTThis paper studies the dynamic filtration behavior of coal particles in metal fiber felt, by developing a three-dimensional model based on microstructure and arrangement mode of metal fiber felt identified by scanning electron microscope. Discrete element method (DEM) is coupled with Computational fluid dynamics (CFD) to simulate filtration of coal particles in metal fiber felt. The simulation mainly studies the moving trail and deposition characteristics of spherical coal particles. The results demonstrated that coal particles can bypass the metal fibers and enter the inside of the metal fiber felt through mesh channels. The moving trail of coal particles is similar to a broken line. It is also shown that most coal particles are trapped due to the deep filtration of metal fiber felt and the distribution pattern of them is inhomogeneous. The number of particles trapped by metal fiber felt is reduced in the direction of thickness. It is found that coal particles can be trapped not only by randomly arranged metal fibers, but also by coal particles deposited previously. Finally, the kinetic energy loss of coal particles mainly occurs in the initial stage when particles pass through metal fiber felt. And the velocity of coal particles inside metal fiber felt is maintained at 0.15–0.25 m/s.HighlightsA more realistic three-dimensional model was reconstructed according to scanning electron microscope pictures.The particle trajectory, deposition mode of particle groups and speed change of particles were investigated using CFD–DEM in the paper.The simulation method was validated by the experiment.

Highlights

  • Pulverized coal particles produced by combustion is an important source of air pollution (Cai, Zhang, & Bao, 2018; Shi et al, 2018)

  • In order to study the performance of filters, Yue, Zhang, and Zhai (2016) applied computational fluid dynamics (CFD)-Discrete element method (DEM) to analyze pressure drop and filtration efficiency in the simulation and results were validated by the semi-analytical models

  • Driven by the inlet airstream, coal particles bypass the metal fibers and enter the inside of metal fiber felt through mesh channels

Read more

Summary

Introduction

With the process of urbanization and industrialization, the consumption of coal, oil and other non-renewable energy is increasing rapidly. As computational capabilities are improved greatly, it is possible to predict the filtration performance of it in advance (Liu, Xu, & Liu, 2016; Mou, He, Zhao, & Chau, 2017; Ramezanizadeh, Nazari, Ahmadi, & Chau, 2019; Xu, Liu, & Pang, 2016) These studies didn’t consider the impact of particle deposition on filtration process, they were only fitted for the initial period of filtration. In order to study the performance of filters, Yue, Zhang, and Zhai (2016) applied CFD-DEM to analyze pressure drop and filtration efficiency in the simulation and results were validated by the semi-analytical models. A threedimensional model was reconstructed to simulate spherical particles in filtration process by computational fluid dynamics (CFD) and discrete element method (DEM). The mimic structure was used by researchers to study the pressure drop and filtration efficiency of fibrous media They keep the porosity of the model consistent with that of the actual material. The study aims to analyze the particle trajectory, the deposition mode of particle groups and the speed change of particles during the whole process

Equations governing gas phase
Equations governing particle phase
Coupling algorithm of gas-solid phases
Drag force model
Fiber felt model
Simulation conditions
Computational grids
Solution control
Particle filtration process
Particle deposition distribution
Analysis of particle velocity and kinetic energy
Experiment to verify the reliability of simulation method
Conclusions
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call