Performance of a cyclone scrubber in removal of fine particulate matter

Abstract

Cyclones are not classified as effective devices for removing fine particles, while high efficiency wet scrubbers usually have high operational costs. In order to achieve better performance, the aim of this study is to evaluate, for the first time, a cyclone scrubber design based on the dimensions of a Stairmand cyclone separator with the inclusion of liquid injection nozzles located in different positions to improve the separation of fine particles. Given the lack of studies considering the effect of liquid injection and other operational conditions in the removal performance of a cyclone scrubber with Stairmand dimensions, the present paper provides a complete evaluation of these effects for the separation of sugar cane bagasse ash from air. The parameters investigated were inlet gas velocity, liquid injection position, liquid-to-gas flow ratio and droplet size distribution. The cyclone scrubber performance was evaluated considering collection efficiency and pressure drop. Overall efficiency of almost 99% and low-pressure drop was achieved by employing a liquid-to-gas flow ratio of 0.43 L/m3 for the collection of ash from the combustion of sugar cane bagasse. Grade efficiencies revealed that injecting droplets into cyclones sig- nificantly improved the removal of fine particles with an aerodynamic diameter less than 2.5 µm.