Abstract
All continuous miner sections use water sprays for dust control. Poor choice of spray nozzles together with improper location of the nozzles and low air flow to the face will cause the dust cloud to roll back toward the operator, however. To minimize this rollback and reduce dust concentrations at the operator location, the Bureau of Mines tested various combinations of air curtains in a full-scale model mine. A system of three or four tubes mounted on the miner cab and alongside the miner discharged air through longitudinal slots. The range for air flow to each of the tubes was about 0.07 m3/s to 0.14 m3/s (150-300 ft2min). In general, the air curtains proved effective. At the miner-operator position, they provided dust reductions of 63 to 99 percent over the use of no tubes under the conditions tested.