Experimental analysis on the capture of submicron particles (PM0.5) by wet electrostatic scrubbing

• New measures on wet electrostatic scrubbing of particles finer than 500 nm is shown.
• Effects of drop size and charge on charged particles capture were investigated.
• Particle scavenging rates can be determined and modeled with appreciable precision.
• Wet electrostatic scrubbing is far more efficient than wet scrubbing for PM<0.5.

This work describes the results of experimental tests aimed to study the wet electrostatic scrubbing of submicron particles produced by a combustion process. A new experimental setup was adopted in order to allow the use of an electrospray exerted in dripping mode in place of a conventional spray, whose complex electro-hydrodynamics limits the quality of the information which can be inferred from experimental work. Experiments were carried out to assess the scavenging rate obtained when droplets of different sizes which were positively charged were used to scrub negatively charged combustion particles having diameters finer than 500 nm. In the investigated conditions, the particle scavenging mechanism is mainly related to the electrostatic interactions between charged droplets and particles. A particle scavenging model adopted to describe atmospheric scavenging phenomenon, once properly fitted to the experimented conditions, was used for the interpretation of experimental results.