Unipolar diffusional charging of fibrous aerosols—Theory and experiment

Models for the unipolar charging of fibers were developed. The theoretical models using idealized geometries—either prolate spheroids or cylinders—and considering both the free-molecular and continuum cases served as a basis for numerical simulations. Simulation results showed that the fibers can carry more charges than equal surface area spheres. In the experimental component of this study, a prototype charger was designed and constructed. The rate of charging was measured as a function of fiber length and charger parameters. It was found that the fiber collection efficiency depends both on charge numbers and the aerodynamic drag of the fiber. The fiber length classification can be achieved by electrostatic precipitation.