Development of Optimal Water Spray Systems for Dust Control in Underground Mines

摘要

Water sprays have been used on continuous miners for many years for bit lubrication, for cooling, and for dust control. Although these sprays do suppress some dust, they can also increase operator dust exposure levels. The air-moving action of the sprays creates recirculation of the dust cloud into the fresh intake air, thus contaminating the operator's breathing zone. This phenomenon is called dust rollback and is caused by sprays with high reach operating at high pressure, particularly in working faces with low primary airflow. The airstream entering the working face is usually clean. If rollback from the face can be minimized, the continuous miner operator can be supplied with clean air. The report describes the laboratory development and field evaluation of a new water spray system for continuous miners that minimizes rollback while maintaining adequate dust suppression. The system, called the Antirollback Water Spray System, uses flat fan sprays operating at low pressure to provide water more efficiently to the cutting zone without creating excessive air turbulence. The system has shown 40% to 50% reductions in continuous miner-generated dust measured at the operator.