Reducing Machinery Noise in Cement Plants

Industrial noise (a pollutant) can cause various kinds of health damage, including temporary or permanent hearing loss. By obscuring conversation it can be a safety hazard. Laws protecting workers consider only audible sounds, intensity, and duration of exposure. However, hearing damage is also influenced by frequency. Infrasonic and ultrasonic noises may be damaging as well. Cement plant noise up to 106 dBA comes mainly from crushers, mills, kiln burners, and compressors. Control measures, including damping, enclosing, and insulating either source or workers, or providing workers with ear-protective devices are illustrated. Mill noise can be damped by massive foundations. Rubber liners can be used to arrest mill noise up to a 10-dBA noise reduction, and other advantages can be achieved. Properly designed enclosures may surround either the source or the workers. Control rooms have noise levels as low as 66 dBA. Expert help is advised for the successful control of cement-plant noise.