Experimental and simulation studies on the capture of micro-particles by a single droplet

Abstract

Coal, as a principal fossil energy source, occupies a crucial role in the global energy landscape. Nevertheless, the fine particles generated during the combustion of coal have exerted severe negative influences on human health, air visibility, and equipment safety. This paper focuses on wet flue gas desulfurization and collaborative dust removal technology as the research context. High-speed photography technology was employed to record the motion behavior of silica (SiO₂) particles impacting deionized water, thereby the suspension/sinking phase diagram of the particles was obtained, and a fitting relationship between the particle size and the critical sinking velocity was established. The relationship was employed as the boundary condition and integrated with the Discrete Phase Model (DPM) in Computational Fluid Dynamics (CFD), and then the capture efficiency of micron-sized particles depositing onto the surface of liquid droplets was studied quantitatively. Moreover, the deposition distribution was explored by developing User Defined Functions (UDF). Finally, the influence of parameters such as particle sphericity, droplet diameter, airflow velocity, temperature difference, and droplet deformation rate on the capture efficiency, deposition distribution, and capture mechanism was elucidated, thereby providing theoretical support for the efficient removal of fine particles.