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

Abstract

Background & objectives: 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. Methods: 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: 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%. Conclusion: 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.

Evaluation of flow, supply, and demand for noise reduction in urban area, Hamadan in Iran

“…The neighborhoods with the highest demand are 415, 413, 407, 406, and 405, respectively. Golmohammadi and Aliabadi [ 31 ] showed that the main external source in medical centers is traffic noise, which is unavoidable, continuous, and increasing. In this study, the sound level varies between 69.65 and 90.79 dB; which indicates that the studied hospitals suffer from noise pollution.…”

“…Urban road traffic is the most significant external source of noise in hospitals, which is unavoidable, continuous, and increasing. Therefore, it is important to pay close attention to the demand for traffic noise reduction in the patient’s recovery process [ 31 ]. Residential areas are the other sensitive land use that can adversely affect the physiological and psychological well-being of citizens.…”