Unipolar diffusional charging of fibrous aerosols—Theory and experiment

Unipolar field charging of particles by electrical discharge: effect of particle shape

“…Experimental data have to be collected on non-spherical particles in order to take into account this parameter in charging laws. In the context of asbestos removal, a few studies have been done, both experimental and theoretical (see Han & Gentry, 1993), but only for di usion charging. Moreover, these studies concern ÿbrous aerosol, and models are based on cylindrical shape.…”

Field and Combined Diffusional and Field Charging of Fibrous Aerosols

“…The nonspherical particles are cylinders which represent an idealized model of a fiber. Previous simulations with the capped model (the fiber is modeled by a cylinder and capped by two hemispheres at the ends) was found to give results similar to that of the cylinder when the fibers were long (Han, 1992). For the experimental studies with fibers in related work, the aspect or length to diameter ratio ( P ) was greater than 50, so that the cylinders were a reasonable approximation.…”

“…Numerical simulations for for diffusional charging showed that for large-sized fibers the image correction is relatively unimportant (Han, 1992). For simplicity, one assumes that the conductive fiber major axis is perpendicular to the electric field (or in other words that the z axis is parallel to the flow direction).…”

Experimental Design of High Volume Electrostatic Charger

“…The corona charging was accomplished by six (diameter 50 pm) wires which were mounted around a Teflon rod holder and maintained at a high electric potential (> 5 kV). The Teflon support for the gold wires had a diameter of 0.038 m. The porous metal cylinder surrounding the cage was grounded and had an internal diameter of 0.102 m. The length of the porous metal section was 0.203 m. Gold wires were used as the corona wires because gold was found to be resistant to oxidation (Han, 1992;Han et al, 1993 was calculated assuming that the inner cylinder was at the corona voltage, this gives an electrical field of approximately 1.3 kV/cm at the center of flow in the charger. The operations were carried out at voltage above 5 kV which was the threshold voltage for corona discharge.…”