Research on characteristics of removing particles in ship exhaust gas by charged droplet

A traditional water scrubber is able to remove particles with a size over 200 μm in ship engine exhaust effectively. However, as the size of the particles decreases, the removal efficiency of the particles is gradually reduced, especially when the particle size is less than 50 μm, the method almost has little effect. This paper presents a study of charging particles in exhaust gas and water droplets to improve water scrubber’s efficiency in removing fine particles. The charging of the particles is mainly achieved through corona discharge, while the water droplets are charged by passing the high-voltage electricity to the nozzle. However, the feasibility and economics of these two methods have not been verified in other researches, so they are numerically simulated by Comsol Multiphysics software in this paper. The simulation results show that both particles and droplets can be charged steadily by the two methods. The numerical simulation results also indicate that the removal efficiency of particles in ship exhaust gas can be greatly improved by adding charges to droplets and particles at the same time. And a line chart of particle capture efficiency map under different particle sizes and change of droplets is obtained