It has been noted [76] that partial charging
reduces the collection efficiency for nanoparticles
smaller than 30 nm in a traditional wire-in-plate
ESP. It is also known that the collection efficiency
of ESPs for nanoparticles decreases sharply as operation time increases, because particles deposit on
both the collection plates and high-voltage electrode, reducing the electric field [76]. Therefore,
Airborne Nanoparticles: Control and Detection,
Fig. 12 (a) Collection efficiency of Al 2 O 3 and NaCl
particles as a function of size for two different gas
velocities in the two-stage ESP. (b) Collection efficiency
of Al 2 O 3 and NaCl particles as a function of size for a
single-stage ESP. (Reprinted with permission [72])
108
Airborne Nanoparticles: Control and Detection