Dust Control Handbook for Industrial Minerals Mining and Processing

Performance Testing of EquipmentDue to the number of possible maintenance issues, performance testing should be done tomonitor the condition of spray equipment on a regular basis, considering numerous factors.Application-specific analysis or measurements. The dust content of the air should besurveyed and checked either visually, to determine the effectiveness of the spray atremoving dust, or by using dust monitoring equipment that measures dust content in air.Visual inspection consists of simply observing the dust-producing area to determine if thespray system is effectively controlling the dust condition. Because this method ofmonitoring does not quantify the dust loading and is subject to operator interpretation, itdoes not specifically measure the efficiency of the spray system. Dust particlemonitoring equipment is available that will quantify the dust loading in the problem areaand provide a more accurate assessment of the system efficiency.Flow rate. The eye cannot necessarily detect increased flow, so the flow rate of eachnozzle should be checked periodically by reading the flow meter or collecting the sprayin a container. The results should be compared to specifications or to the performance ofnew nozzles.Spray pressure. Pressure in the nozzle manifold should be checked using a properlycalibrated pressure gauge.Spray pattern. In many instances visual inspection is adequate for monitoring patternuniformity. Changes caused by orifice damage, clogging, or caking are usuallynoticeable. However, to detect gradual orifice wear, special measuring equipment will berequired. A flow meter may be used to compare the flow of a new nozzle at a specificliquid pressure to the flow of a used nozzle at the same pressure. Nozzle wear causes theflow to increase so the flow meter reading is a quantifiable indicator of the degree oforifice wear.Nozzle alignment. To provide uniform coverage, nozzles should be oriented correctly inrelation to one another so that all like patterns are parallel.REFERENCESBartell W, Jett B [2005]. The technology of spraying for dust suppression. Cement Americas,May/June pp. 32–37.Blazek CF [2003]. The role of chemicals in controlling coal dust emissions. Presented at theAmerican Coal Council PRB Coal Use: Risk Management Strategies and Tactics Course.Dearborn, Michigan, June 2003.NIOSH [2003]. Handbook for dust control in mining. By Kissell FN. Pittsburgh, PA: U.S.Department of Health and Human Services, Centers for Disease Control and Prevention,National Institute for Occupational Safety and Health, NIOSH Information Circular 9465,DHHS, (NIOSH) Publication No. 2003–147.Wet Spray Systems 75