The noise pollution is considered nowadays a crucial aspect in the selection and construction of manufacturing plants. Sound or noise barriers, such as walls or insulated components, are designed to create an acoustic shadow by blocking the free flow of sound waves. The reduction in sound level within this shadow zone behind the barrier is dependent on frequency. At high frequencies, the effect of the barrier is clear, when in low frequencies (long wavelength) the shadow effect is diminished.
The attenuation of a screen is mainly determined by the effective screen height, H, and the width of the screen compared to the size of the noise source. For acoustic insulation R&M mean all systems and operations constituting the efforts aimed at hindering, in a more or less complete way, the passage of sound energy coming from a noisy source , such as not to allow transmission to other bodies or to the surrounding environment. Noise that we deal with is classified as: Industrial Noise and is the one caused by industry machines, equipment and piping. It entails noise pollution caused by machines from machines in various factories, plants (e.g. Power Generation and Oil & Gas), industries and mills. Other crucial factors have to be determined, such number of exposed workers, type of work, amount of time spent to the noise’s exposure etc. Where possible, noise levels should be evaluated at locations occupied by workers’ ears. The noise control planning is based on a “A weighted immission” (or noise exposure levels) for which the respect of standard ISO 11690 1 is recommended.