This paper describes a strongly coupled calculation procedure for the particle dynamics in electrostatic precipitators (ESP) subjected to the applied magnetic field with the statistical particle size distribution taken into account. The turbulent gas flow and the particle motion under external forces are modeled by using the commercial computational fluid dynamics (CFD) code FLUENT. Numerical calculations for the gas flow are carried out by solving the Reynolds-averaged Navier-Stokes equations and turbulence is modeled using the k − ε turbulence model. An additional source term, which is obtained by solving a coupled system of the electromagnetic field and charge transport equations, is added to the gas flow equation to capture the effect of electromagnetic field. Discrete Phase Model (DPM) is employed to achieve the simulation of the particle phase. Different kinds of particles which follow Rosin-Rammler distribution were simulated under different conditions, and the influence of magnetic field density on the capture of fine particle was investigated. In order to show the dust removal effect, the collection efficiency and the escaped particle size distribution were discussed in case of different applied magnetic fields. The particles trajectories inside the ESP were also given under the effects of both aerodynamic and electromagnetic forces. Numerical results indicate that the collection efficiency increases with the increase of applied magnetic field, that the particles trajectory are more visible to the direction of dust collection plate, and that the collection efficiency varies smoothly when the applied magnetic field is up to a certain value. Furthermore, the average diameter of escaping particles decreases and the dispersion for dust particles in different size increases with applied magnetic field increasing, and particle sizes is linearly decreasing with magnetic field before the particle reaches a certain size.

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The aim of this work is to find an effective method to improve the collection efficiency of electrostatic precipitators (ESPs). A mathematic model of an ESP subjected to the external magnetic field was proposed. The model considered the coupled effects between the gas flow field, particle dynamic field and electromagnetic field. Particles following a Rosin-Rammler distribution were simulated under various conditions and the influence of the magnetic field density on the capture of fine particles was investigated. The collection efficiency and the escaped particle size distribution under different applied magnetic field intensities were discussed. Particle trajectories inside the ESP under aerodynamic and electromagnetic forces were also analyzed. Numerical results indicate that the collection efficiency increases with the increase of applied magnetic field. It was also found that a stronger applied magnetic field results in a larger particle deflection towards the dust collection plates. Furthermore, the average diameter of escaping particles decreases and the dispersion of dust particles with different sizes increases with the increasingly applied magnetic field. Finally, the average diameter decreases almost linearly with the magnetic field until it drops to a certain value. The model proposed in this work is able to obtain important information on the particle collection phenomena inside an industrial ESP under the applied magnetic field.

A design of IIR digital filter based on DSP and SOPC technology was respectively conducted in this paper. Then design principles and implementation schemes were put forward, and the schematics of the hardware circuits as well as the software flow chart were given in detail. The experimental results indicate that the SOPC design has the advantages of flexible controls, continuous output phase, high precision, high reliability, and that it has better application value compared with the method by using the DSP chip under the integrated development environment CCS (code composer studio).