Turbulent mixing in a barbed plate-to-plate electrostatic precipitator

The electrical and fluid dynamical characteristics of a barbed plate-to-plate electrostatic precipitator are compared with those of a conventional wire-to-plate precipitator under particle-free conditions. The barbed plate electrode design is based on the concept that a more uniform distribution of current within the flow channel may reduce the scale of the corona-induced electrohydrodynamic flow and thus decrease particle mixing. Current-voltage relationships and hot-film anemometer measurements of turbulence intensities, integral length scales and eddy diflusivities are presented for current densities as high as9mAm⁻²at gas speeds of 0.5,1.0 and 2.0 m s⁻¹. Visual inspection of the discharge pattern indicates that the scale of the current inhomogeneity is reduced. Flow visualization and measurements of integral length scales confirm that the barbed plate design does reduce the scale of the electrically induced flow. Even though downstream turbulence levels are increased in the planar geometry, gas diffusivities are not substantially reduced. Additional study of the inter-electrode gas flow field and particle collection efficiency is necessary to determine the practical viability of the barbed plate precipitator.