Size distributions for aluminum and other particles were measured and correlated by lognormal size distribution functions. It was concluded that particle size was controlled by particle collision and coalescence processes. More experimental studies are needed using a wider range of materials and operating conditions, with well-controlled geometries and flow regimes. The experimental results need to be analyzed in light of our understanding of aerosol formation processes. While the EC generator operated in the batch mode has a low production rate, it offers the possibility of limiting contamination, since chemical reactions are usually excluded or limited.
Particle size is determined by the rates of particle collision and subsequent coalescence.
Stable nuclei collide and, initially, coalesce to form larger particles. The particles may be liquid or solid during the coalescence period. Coalescence ceases or slows significantly, leading to the formation of agglomerate structures. Coalescence and neck formation may continue for particles within the agglomerate structures. These processes may go on simultaneously.