Effect of Scrubber Operation Parameters on Droplet Size, Droplet Velocity and Dust Suppressibility

Kim, Jin; Kim, Du-Young

Environmental Engineering Research 1997;2(4): 279-286.

¹Departmeent of Mineral and Energy Resources Engineering Inha University, Incheon, Korea
²Department of Mineral and Energy Resources Engineering Inha University, Incheon, Korea

Corresponding Author: Jin Kim ,

Received: April 10, 1997; Accepted: August 10, 1997.

ABSTRACT

Advantages gained from the addition of surfactants to water sprays used for dust suppression may be related in part to their effect on droplet size. A spray with surfactants generates finer droplets because they lower the surface tension but the finer droplets rapidly lose kinetic energy or velocity. This article is aimed at providing precise measurements of droplet size and velocity through the use of a Phase Doppler Spray Analyser (PDSA) and to discuss the effect of the scrubber operating parameters on droplet size and velocity in relation to dust suppressibility. The measurement results show that the addition of a surfactant or the increase in the surfactant concentration does not impact the droplet size or velocity as significantly as the increase in nozzle pressure. Improved dust collection efficiency, obtained by adding surfactant into water, must be achieved not by a change in droplet parameters such as size and velocity, but by the improved wettability (adsorption of surfactant molecules on a coal particle). In addition, the use of the surfactants reduces the surface tension of the liquid droplet Reducing the surface tension of the droplet should make particle penetration easier, requiring less energy. Conclusively, the collection efficiency or suppressibility is a function of mutual wettability among particle and droplet (adsorption of surfactant), and the liquid surface tensioa