A model for the deposition of charged particles in an electrically grounded cylindrical tube in the absence of an applied electric field is investigated. The underlying particle size distribution of the influent aerosol is discretized into a finite number of fractions. Each fraction has a representative particle size that determines the charge and diffusivity of particles in that fraction. A transport equation is obtained for each fraction by considering the radial electrostatic, radial diffusional, and axial advective fluxes. The electrostatic flux depends on the strength of the electric field that arises from the space charge due to the particles treated as a continuum. At short distances into the tube, radial transport toward the wall is dominated by the electrostatic flux of larger particles. At intermediate distances, the contributions of both the diffusional and electrostatic fluxes are important. Farther down the tube, radial transport is dominated by the diffusional flux of smaller particles, with the remaining larger particles persisting in the gas stream. Assuming a single mean particle size, in lieu of a realistic treatment of the actual distribution, can result in inaccurate predictions of particle capture.
All Science Journal Classification (ASJC) codes
- Environmental Science(all)
- Charged particles
- Electrically grounded cylindrical tube
- Size distribution