Improving the efficiency of a flooded-bed dust scrubber using a modified demister

Abstract

Dust generation is a significant issue in the U.S. mining industry, particularly the underground coal mining industry. It causes health and safety issues for the miners working underground. Prolonged exposure to high concentrations of respirable dust (dust of aerodynamic diameter < 10 μm) causes various diseases, including pneumoconiosis, also known as Black Lung, and silicosis. These diseases lead to an airflow blockage in the lungs, causing lung failure or death. Several techniques have been used to capture respirable dust particles, and a flooded-bed scrubber integrated into a continuous miner is one of them. This research focuses on increasing the efficiency of a flooded-bed scrubber by modifying the geometry of one of its components, known as a demister. A demister consists of a series of sinusoidal plates that separate water droplets from air and contribute to the capture efficiency and pressure drop across the scrubber. The geometry of the demister was modified by adding aerodynamic devices, called Vortex Generators (VG), on its plates. Several computational fluid dynamics (CFD) models of a modified demister were created, and CFD simulations were performed. An analysis of results indicated an improved water droplet capture efficiency for the modified demister. The study also discovered a potential to reduce the size of the demister which will reduce the pressure drop and eventually the energy consumption of the scrubber.