In a power plant, a generator is a very powerful noise source, potentially causing sound nuisance for the personnel of the operator operating in the vicinity as well as for the neighborhood (more so in the case of outdoor installation). It is often necessary to use in such cases a high-tech soundproofing equipment (enclosure) to ensure the conformity of the facility on the one hand with respect to the legislation on noise at work and on the other hand with respect to the regulation in terms of environmental protection.
ITS will participate in the construction of a noise enclosure for an air-cooled industrial generator built for a power plant (46 MW) for a mining facility in Australia.
This soundproofing device will offer a sound reduction particularly important at low frequency where the maximum of the noise emission of the enclosed noisy equipments is (a sound pressure level of 134 dB in the 1/3 octave frequency band of center frequency 100 Hz has been accounted inside the central compartment of the enclosure), requiring a specific design and a specific construction of the partitions and of the ventilation system.
The design of the walls and the roof of the enclosure will be metallic:
- with an inner layer of mineral wool, surfaced by a glass veil and protected by a perforated sheet; instead of being reflected (due to the physical limit to the acoustic propagation caused by the presence of a partition), the sound waves will be absorbed, thus limiting the increase in the sound pressure level inside the enclosure, resulting from the reverberation phenomenon
- with a solid outer sheet, made of steel ; the noise transmission (in particular at low frequency, which is fundamental in the case of sound emissions from an alternator) namely depending on the mass density i.e. the product of the density [1] by the thickness (at higher frequencies, that should not be neglected, the acoustic performance is in addition a function of Young's modulus [2], Poisson's ratio [3], internal loss factor [4]
Related features such as weather resistance, disassembly of the whole and of subsets, securities, lighting, electrical works ... will be integrated according to the needs to this enclosure for a generator. Meeting numerous and varied technical objectives will therefore be necessary to carry out successfully this industrial soundproofing project; one can count on the professionalism of ITS and of its business partners in this field of noise emissions limitations in the energy sector.
typical values for regular construction steel
[1] 7800 kg/m3
[2] 210 109 N/m2
[3] 0.3
[4] 0.01