High-temperature dust removal is one of the important procedures for integrated coal gasification combined cycle. In this work, a moving granular bed filter that can separate the mixture of particles of different sizes spontaneously was designed. We studied the flow characteristics of binary particles in the filter based on the discrete element method (DEM). We gave the formation process of the boundary between the stationary layer and the flowing layer, which should have a reference value for the control of the stationary layer and the design of the filter inclined groove. Typical separation trajectories of large and small particles during size segregation were also given. The degree of size segregation decreased with the increase of the mass flux of particles. Real-time control of the large particle layer thickness in the filter area can be achieved by changing the mass fraction of the inlet large particles.

Transformation plays a significant role in solving hydrological problems. In response to the comment on Singh and Das (2015) by Deng et al. (2015) regarding the transformation, boundary conditions and subsequent analytical solution of advection dispersion equation in semi-infinite heterogeneous porous media, it is argued that the transformation used by Singh and Das (2015) for finding the analytical solution is correct and mathematically valid. Also, the different expression of f(mt) used to obtain the solution are explained with their physical relevance in the field.

Introduction: The computational fluid dynamics (CFD) simulation of three-dimensional wire-plate electrostatic precipitator is performed in the present study. Materials and methods: The momentum equation, the electric potential equation and current continuity equation are solved by using ANSYS Fluent. The ion charge density at the corona is calculated iteratively using the Peek formula. The SIMPLE algorithm is used to treat the pressure-velocity coupling. The RNG k-ε model is used to describe turbulence. Results: The airflow keeps stable away from the first corona electrode. The distribution of the electric potential is dependent on the wire-plate distance and the wire-wire distance. The potential and ion charge density increase with the increase of the wire-plate distance. With the increase of wire-wire distance, the maximum electric field strength decreases whereas the maximum ionic charge density increases. The ion charge density near the second corona electrode is relatively small. A small wire-wire distance will make the electric field concentrated around the wires. Conclusion: According to this study, the wire-wire distance and the wire-plate distance have great effect on the distribution of ion charge density and electric field strength.