Experimental study of fine particles removal in the desulfurated scrubbed flue gas

Droplets growth by heterogeneous condensation of water vapor as a preconditioning technique for the removal of fine particles from flue gas was investigated experimentally in a wet flue gas desulfurization (WFGD) system using spray scrubber as scrubber. The supersaturated vapor environment was achieved by adding water vapor into the particle growth region, which was above the liquid phase inlet in the desulfurization tower. Fine particles grow in size by vapor heterogeneous condensation with the particles acting as nucleation centers, and then the grown droplets are removed efficiently by a high-efficiency wire mesh demister. The results show that particle number concentration decreased significantly by application of heterogeneous condensation of water vapor in the WFGD system. The influence of initial particle number concentration, temperature of inlet flue gas and desulfurization solution, amount of steam added on the removal efficiency of fine particles is presented. The removal efficiency of fine particles decreased with increasing the initial particle concentration. Anyway, heterogeneous condensation in combination with a WFGD system is a highly efficient technique for the separation of fine particles from the desulfurized flue gas.