Evaluation of various improvements to an innovative wet scrubber concept to increase particle removal efficiency

RWTH Aachen University, E.ON Energy Research Center, Institute for Energy Efficient Buildings and Indoor Climate, Germany

^* Corresponding author: nhat.nguyen@eonerc.rwth-aachen.de

Abstract

With increasing filter efficiency, the need for energy-efficient methods to improve indoor air quality has grown. The investigated wet scrubber concept has lower pressure losses across the device compared to conventional wet scrubbers. The produced droplets in this wet scrubber are significantly larger than those produced in conventional wet scrubbers that use injectors to atomize the water. Larger droplets result in a reduced interface between water and particles. Therefore, while the new wet scrubber concept is more energy-efficient, it achieves lower particle removal efficiencies than conventional wet scrubber methods. Hence, various adaptions such as additives or surface modifications are used to increase the particle removal efficiency. Additives containing silicone and a rougher surface improve the particle removal efficiency by a factor of 3. However, combining the two does not improve the particle removal efficiency much more than the additives alone. Increasing the hydrostatic pressure on the perforated plate facilitates the water dripping and reduces the average droplet diameter, thereby increasing the water-particle interface. At twice the Weber number, the particle removal efficiency increases by a factor of 2.5 resulting in a particle removal efficiency of 67 % for larger particle diameters.