Electrical Re-entrainment of Particles in Wire-Duct Electrostatic Precipitators
M. Abdel-Salam1, M. Th. El-Mohandes1, H. Wedaa1, S. Kamal El-deen1, and N. Zouzou2
1Electrical Engineering Department, Assiut University, Egypt
2Pprime Institute, CNRS-Poitiers University-ENSNA, France
Abstract- This paper is aimed at investigating the re-entrainment phenomena of particles in wire-duct electrostatic precipitators. This calls for assessment of the forces acting on a particle positioned in the precipitator nearby the collecting plate. These include Van Der Waals, Johnsen Rahbek and repulsion forces. Van Der Waals and Johnsen Rahbek forces are directed toward the collecting plate and repulsion force is directed opposite toward the discharge wire. Re-entrainment takes place when the repulsion force exceeds the resultant of both the Van Der Waal and Johnsen Rahbek forces. To estimate the repulsion force, the electric field acting on the particle is required as calculated by using the charge simulation method. Conducting and dielectric particles are investigated, where the conducting particle is simulated by inner charges. However, the dielectric particle is simulated by inner and outer charges. Satisfaction of pertinent boundary conditions results in a set of equations whose solution determines the values of the simulation charges. With the determination of the simulation charges, the electric field and hence the repulsion force are evaluated. Re-entrainment takes place for dielectric particles at particle radius greater than 1 μm in agreement with previous findings. The particle radius values at reentrainment are smaller than those for metal ones.
Keywords-Electrostatic precipitator, particle re-entrainment, Van Deer Waal force, Johnsen Rahbek force, charge simulation method