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High-pressure shrouded water sprays for dust control.

Jayaraman NI; Kissell FN; Cross WG; Janosik J; Odoski J
Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 8536, 1981 Jan; :1-16
High-pressure shrouded sprays were first tested on a bench to determine air-moving capability and dust collection efficiency. The bench-scale tests indicated that at 500 psi and above, the dust collection efficiency, when sampled downstream of a water eliminator, was about 99 pct for two types of nozzles. However, for the same water flow, the induced airflow was about three times greater in one type than in another. Since the only difference in the nozzles was the spray angle, this factor was important in air movement through a shrouded spray. Full-scale model mine tests were then conducted to determine the reduction in dust concentration behind the line curtain and at the operator position produced by high-pressure sprays in a shroud. The shroud was mounted on top of the boom of a model continuous miner, and high-pressure (greater than 500 psi) sprays were installed inside the shroud. The inlet of dusty air to the shroud was open toward the face and the outlet toward the exhaust line curtain. The high-pressure sprays were compared with conventional sprays mounted at the head of the continuous miner and directing water toward the face. The difference at the operator position (opposite side of brattice) was significant in that, under certain conditions, with conventional sprays an increase in respirable dust concentration of 471 pct was noticed compared with dry operation due to rollback from face. High- pressure shrouded sprays, on the other hand, decreased the dust concentrations at the operator position (opposite side of brattice) by 28.2 pct.
Coal mines; Mining equipment; Dust control; Spray nozzles; Spraying; Dust collectors; Air washers; Continuous mining machines
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High-pressure shrouded water sprays for dust control
Page last reviewed: October 29, 2021
Content source: National Institute for Occupational Safety and Health Education and Information Division