Designing an Enclosure in Order to Control the Equipment Noise in Screw Manufacturing Industry

Noise reduction in the source is always in priority. For acoustic engineers, taking a systematic approach and considering small details of designing an enclosure can be one of the most effective ways of noise reduction. This study was carried out to detect major noise generator sources in a screw manufacturing company. In this interventional study, primarily information were collected, including machines' specifications, number of workers exposed to noise, time of exposure, and their deployment location. Then environmental assessment was carried out to assess the noise level around the sound source and dosimetry devices. Finally, a design of an enclosure was developed to control noise level in machines producing noise. Results indicated that BV2 and BR3 machines, with total sound pressure level of 95.7 and 94.4 dB, were major sources of noise, which exceeded the noise limit. To control the generated noise of the mentioned machines, an enclosure was designed with minimum damping of 19 dB. The designed enclosure consisted of a compact layer of 3 mm steel, a layer of 20 mm self-stick foam, a layer of 40 mm mineral wool and a 1 mm layer of punched aluminum plate with open mouth of 60%. the designed enclosure for BV2 and BR3 machines can empirically reduce sound pressure level by 19.3 and 19.7 dB respectively and the exposure of operators was reduced to 76.4 and 74.7 dB, which provides safety for workers of the factory.