Numerical simulation of the flow and the collection mechanism inside a scale hybrid particulate collector

Numerical technology has been widely used for the study of the electrostatic precipitators (ESP) and the bag filters. This paper presents a numerical model for a scale hybrid particulate collector (HPC), which combines the ESP technology and the filtration technology together. The collection process of the HPC is unsteady as the pressure drop across the bag filter increases with the deposition of the particles. The physical processes of the model include the corona discharge, the fluid flow, the particle charging and the filtration. The corona discharge field is solved by using a finite volume method. For the fluid field, the unsteady and incompressible Navier–Stokes equations with the RNG κ–ε turbulence equations are solved. The effect of the electric field on the fluid field named electro-hydrodynamic is also considered. For the particle charging, the filed-diffusing combined model of Lawless (1996) [37] is adopted. For the filtration, an unsteady cake formation model is proposed. The pressure drop across the cake is calculated according to the mass density of the cake. The coefficient between the pressure drop and the mass density of the cake comes from the experimental data. Applying the numerical model to the HPC, the influence of the hole diameter of the perforated-plate on the collection efficiency of the electrostatic zone is analyzed. Numerical results show that the collection efficiency of the electrostatic zone of the HPC has no certain relation with the hole diameter of the perforated plate. The effect of the hole diameter of the perforated-plate on the collection efficiency of the electrostatic zone becomes weaker with increasing the applied voltage.

The numerical simulation of the filtration process in the hybrid particle collector is presented. The surface of the fibrous bag is divided into several slices. The size and the mass flux of the particles deposited on these slices are recorded. And then the pressure drop of the particle layer is calculated according to the particle parameters.Figure optionsDownload as PowerPoint slideHighlights
► Development of a numerical model for a scale hybrid particulate collector, which combines electrostatic and filtration together.
► The parameters of the deposited particles on the bag surfaces are recorded and used to compute the pressure drop.
► The influences of the hole size of the perforated-plate on the collection efficiency of the electrostatic zone are analyzed.