Dust Control Handbook for Industrial Minerals Mining and Processing

a seal at the entry and exit points of the vehicles. Alternatively, flexible plastic stripping orcurtains can be used to construct the entire enclosure as shown in Figure 7.7. In either case, theindividual pieces of flexible material should overlap one another to provide a more effectivebarrier against the possibility of dust escaping. To further prevent dust escape, the enclosureshould be supplemented with a dry dust collection system. Equation 4.1 in Chapter 4—Crushing, Milling, and Screening, can be used to calculate an initial exhaust volume for the drydust collector. If dust is seen escaping the enclosure, it is an indication that an effective seal isnot being maintained, that the exhaust air quantity is not sufficient, or both.Figure 7.7. Rail car loadout area enclosed with plastic strips to contain dust.The following is a list of some issues that should be addressed in designing the loading processand the loadout area so that personnel do not need to enter the enclosure.Vehicle hatches should be opened and closed outside of the enclosure.Cameras can be installed to assist the operator in properly positioning the loading spoutto minimize dust generation and spillage.An automatic level sensing kit should be installed to signal the operator when the vehicleis fully loaded or to automatically shut off the feed. Several types of sensor technologiesare available and include tilt, pressure, capacitance, or infrared. This automation allowsthe operator to maintain a more remote position from the area where dust might begenerated.The loading spout can be raised automatically after the vehicle is loaded to a predefinedheight, which allows the vehicle to move away without the spout being fully retracted.This ensures that sufficient clearance is available and reduces the time required to beginthe loading of the next vehicle. Level sensors and limit switches can be used to helpaccomplish this effort. Once again, this automation allows the operator to maintain amore remote position from the area where dust might be generated.During loading and until all liberated dust is cleared, personnel should not be allowed toenter the enclosed area. The loading process should be designed so that it is notnecessary for personnel to enter the enclosure. If personnel must enter the enclosure, dustconcentrations within the enclosure should be quantified in order to ensure thatappropriate respiratory protection is utilized.Bulk Loading 195