Improve Drill Dust Collector Capture Through Better Shroud and Inlet Configurations

Overexposure to airborne respirable crystalline silica (or quartz) dust can cause serious or fatal respiratory disease. In particular, some of the most severe cases of silicosis have been observed in surface mine rock drillers. A voluntary lung screening study conducted on surface coal mine workers in Pennsylvania concluded that the incidence rate of silicosis is directly related to age and years of drilling experience. Dust sampling data from the Mine Safety and Health Administration show that the drilling machine operator continues to frequently exceed the federally mandated quartz dust standard. Dry dust collection systems tend to be the most common type of dust control incorporated into drilling machines by original equipment manufacturers because of their capability to operate in various climates. This system includes a selfcleaning (compressed air back pulsing filters) dry dust collector sucking dust from underneath the drill deck shroud, which surrounds the hole being flushed by compressed air (bailing air). Previous drill studies have shown that over half of the dry collector dust emission problems are from the deck shroud and drill stem bushing leakage.