Objective To analyze and evaluate the protective effects of a comprehensive dust control program on coal transfer system of a thermal power plant, and to put forward reasonable and feasible countermeasures for occupational disease prevention to protect workers' occupational health.
Methods Field investigation and detection of occupational health hazards were carried out to evaluate total dust concentration, dispersity, free silica content, and wind speed at dust hood exits.
Results The free silica content ranged from 4.6% to 7.4% with an average of 6.0%. The type of dust in the coal transfer system of the plant was confirmed as coal dust. The dust dispersity was 77.0% for particles less than 5 μm. Before the dust pollution control program, the total dust concentrations of all workplaces exceeded occupational health standards; the unqualified rates of total dust concentrations decreased to 40.0% after the dust pollution control program, including workplaces such as car dumper room, coal field, and the vicinity of coal pulverizer and coal plough. The workers responsible for running screw coal unloaders, coal crushers, and bunker bays were the main population that suffered from exceeded limits on total dust concentrations. The wind speeds at dust hood exits of coal crusher and bunker bay did not meet the design values.
Conclusion Dust pollution in the selected coal transfer system has been significantly reduced after control program applied. Dust removal facilities should be further improved to fully address the dust pollution issues.
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