Technology News 523 - evaluation of dust collector bags for reducing dust exposure of roof bolter operators.
NIOSH 2007 Feb; :1-2
The laboratory dust collector tests showed that 99.6% of the test dust fed into the collector was captured by the dustbags. Figure 1 shows the condition of the main chamber before and after testing. Total weight gain on the canister filter was over five times greater without use of the bag. The RAM-I unit showed respirable dust levels in the collector exhaust to be over two times higher when tests were conducted without the bags in place. The APS showed that the" number of total dust particles emitted from the exhaust was two times greater when the tests were conducted without the bags. Since nearly all the dust is contained in the bag, operator exposure is improved when emptying the collector box's main chamber. Filter loading is greatly decreased when using the bags, enabling longer periods of drilling without filter removal/cleaning. Pressure drop across the filter for all tests ranged from 3.0 to 3.3 in w.g. when the bag was used and from 4.0 to 8.4 in w.g. without the bag. Filtered air emitted from the collector has less respirable dust and fewer total dust particles when the bags are used. These results show that benefits from use of the bags are realized in all areas of operator exposure. In order to use these bags in underground coal mines, the dustbags must be accepted by MSHA as an optional item for the specific dust collection system and machine model (30 CFR 33). In addition, the collector must be equipped with a predump option and must have a retrofit kit installed inside the collector to connect to the bag.
Mining-industry; Mining-equipment; Dust-measurement; Dust-exposure; Dust-control; Dust-collection; Respirable-dust; Underground-mining; Underground-miners; Coal-mining; Coal-miners; Silica-dusts; Control-technology
NIOSH, Pittsburgh Research Laboratory, P.O. Box 18070, Pittsburgh, PA 15236-0070
Numbered Publication; Technology News
(NIOSH) 2007-119; TN-523
National Institute for Occupational Safety and Health