Electrohydrodynamic flow regimes in a cylindrical electrostatic precipitator

This article presents a model of the electrohydrodynamic fields that occur inside an axisymmetric electrostatic precipitator of the wire/cylinder type under laminar flow conditions. Five relevant dimensionless numbers were identified. Besides two geometrical parameters, these numbers include the electric Reynolds number Ree and the hydrodynamic Reynolds number Rea as well as the ratio Σ between the Peek field and the mean electric field between the two electrodes. The dimensional parameters (maximum electric field, air flow rate to be treated and minimum diameter of particles to be treated) have been expressed in the context of these dimensionless numbers. The numerical simulation carried out revealed four flow regimes, due to the finite length of the electrodes, which differ by the number of secondary flows involved. A detailed analysis shows two areas where some of these regimes coexist. This study provides a basis for making a realistic evaluation of the impact of secondary flows on the collection performance of electrostatic precipitators.