INFLUENCE OF WATER INJECTION RATE ON THE VORTECONE, AN IMPINGEMENT SCREEN, AND A CONVENTIONAL FILTER SCREEN CLEANING EFFICIENCY

Industrial produced respirable particles are known to affect the respirable tract of workers causing serious illness or even death. These particles can be found in any mining operation’s environment, new regulations by the Mine Safety and Health Administration (MSHA) in 2014 reduced the allowable limit of dust exposure for underground workers. Dust control practices have been improving over the years to lower the number of incidents caused by these particles. In underground mining, water sprays and scrubber systems have become the most used dust control methods. Water sprays create numerous fine water droplets to capture dust once it has become airborne. The goal of thesis is to determine the influence of water injection on cleaning efficiency of the Vortecone scrubber, a device used to remove paint overspray particles from the airstream in the automotive industry. The Vortecone is compared to a non-clogging screen developed at the Department of Mining Engineering, University of Kentucky, and the conventional screen found in a flooded-bed dust scrubber system in a continuous miner. Tests were done in a random order to prevent experimental contamination; all experiments were repeated three times in order to minimize any systematic errors in the procedures. A total of 18 tests were run to determine the relation between the amount of water flow injected into the system and the cleaning efficiency on each one of the filter systems. Water flows were set at 2.0 gpm (7.57 lit/min), 4.0 gpm (15.12 lit/min) and 6.0 gpm (22.72 lit/min). Additionally, tests were also run in a dry condition (no water flowing through the system), so that the difference between the cleaning efficiency curves with and without water flow could be compared. Airflows were set at 600 cfm and 800 cfm (0.28 m3/s and 0.38 m3/s respectively). JMP statistical software was used to generate the sequence in which the tests were conducted. The results of this study show that both the Vortecone and the impingement screen have great cleaning efficiency overall compared to the conventional screen. The conventional fibrous screen is the only water flow-rate dependent system, while the Vortecone is the filter that requires the lowest amount of water to achieve the best dust capturing rate