شناسایی منبع اصلی مولد صدا در واحد تولید هوا یک صنعت پتروشیمی و ارزیابی اثر محصورسازی آن

Aims: Noise is considered the most harmful physical agents in the workplace which exposure to it can cause the harmful physical and psychological effects on worker. Since the best noise control measures is to reduce or limit the at the source, the purpose of this study was to assess the noise pollution and determine the dominant sound source in an Air production plant of a Petrochemical industry, and also it aims to evaluate the effect of enclosing the dominant sound source on its overall noise level. Methods: The first step, the environmental noise measurement was done by Bruel and Kjaer Type 2236 noise analyzer to measure the levels of noise in Air plant of a petrochemical company based on ISO: 9612 standard. Then, dominant sound source of Air plant was known by referring to noise contour which is drawn by ARCGIS 9.1. In the third phase, noise control enclosure was selected as the best way to reduce the sound pressure level of the main source (Drayer) and finally the effectiveness of the proposed control measure was studied. Results: Results of the assessment of environmental noise revealed that the average sound pressure level of Air production plant was over 88.9 dB A. However, the noise level was over 101 dB A in Compression part of understudy plant. Considering hazard zone at noise contour, it was obvious that in the southern section of Compression, sound pressure level has increased more in comparison with other sections, and in some stations which is exact location of Dryer machinery, SPL has been measured to 100 dB A.Dryer machines of Compression part were known as the main sound source. Considering to the efficacy of conventional methods of noise control and also results of Dryer’s frequency analysis, and the working condition of Air plant, acoustic chamber or enclosure was chosen as the best engineering noise control measure for reducing of noisy Dryer. It was predicted that by providing the enclosure, overall sound pressure level will be reduced about 19/4 dB A. Conclusion: According to assessment of noise pollution in understudy unit, 61.5 % of the measurement stations were in caution area (SPL between 80-85 dB A). However, Exposure to these values of SPL can lead to different health effects in the short term or long term. So, in order to prevent the auditory and non-auditory effects of noise, it is necessary to provide sound abatement measures for other noise sources in this petrochemical plant.