Soundproofing of industrial ventilation hardware is a recurring need, particularly in the energy production sector (e.g. electric, thermal or refrigeration) and gas chemistry, in which many installations involve a large variety of machines (e.g. turbines, motors, compressors, pumps) whose heat dissipation (sometimes: very important, due to radiation and convection phenomena) require a large quantity of thermal energy to be removed, thus involving , air flows linked to ventilation systems.
Consequently, the openings foreseen for the intake of fresh air and the discharge of hot air allow the transmission of the noise (sometimes very important) emitted by these machines, the sound levels (all the higher as the sound power level of the machines is high, that their close environment reverberates the sounds and that the surface of the openings is large) thus being of a nature to cause a problem :
- at a short distance, e.g. with regard to the possible exposure to excessive noise levels of staff working at a fixed position or moving nearby, with regard to the regulations in force in terms of noise at work. In particular, when European directive 2003/10 / EC is taken into consideration :
- the level of daily noise exposure L EX, 8h: 80 dB (A) and 85 dB (A) are the thresholds, respectively lower and upper, triggering the action ; 87 dB (A) is the allowed limit value
- the peak sound pressure ρpeak: 112 Pa i.e. 135 dB (C) and 140 Pa i.e. 137 dB (C) are the thresholds, respectively lower and upper, triggering the action ; 200 Pa ie 140 dB (C) is the allowed limit value
- at medium and long distance, at the limit of industrial property or beyond (e.g. for the neighborhood, which can be harmful when the admissible levels of emergence are exceeded ; for France :
- a limit is set by a prefectural decree e.g. 60 dB (A) at the property line
- emergence i.e. the difference between the A-weighted equivalent continuous pressure levels of ambient noise (installation in operation) and of residual noise (in the absence of noise generated by the facilty, but measured over its period of operation) is legally limited - depending on the case to 5 or 6 dB (A) during the daytime and to 3 or 4 dB (A) during the night period in regulated emergence areas
It is therefore necessary, in those contexts, to provide soundproofing for such industrial ventilation equipment, their design, construction and assembly being marketed by ITS separately or as a whole (according to the Customer's wishes).
The design of soundproofing devices for industrial ventilation equipment must take into account the technical requirements that must be compromised in terms of performance, e.g. acoustics on the one hand and aerodynamics on the other hand, since the interposition of a silencer is accompanied by a total pressure loss which must remain within acceptable limits for the correct operation of the facility in question.
The sizing of such equipment quite often requires iterative calculations, which must be carried out in a fairly short time interval, for which recourse to the SILDIS® software, developed and marketed by ITS (as well as services for the use of this calculation means ) may be appropriate in many ways, including :
- as regards the prediction of longitudinal noise attenuation (e.g. for silencers), in the direction of the air flow or in the opposite direction (cf. Module 1, Module 1A, Module 1B)
- for what has to do with the simulation of noise transmission through silencers casings (cf. Module 3 or Module 2 in the case of large cross sections, Module 5 as well as Module 5A)
- concerning the calculation of the acoustic performance of other elements of ventilation networks (elbows : cf. Module 6, nozzles : cf . Module 7)
The construction of soundproofing equipment for industrial ventilation hardware marketed by ITS is carried out taking into account all the technical requirements related to the considered context (project-based approach), with an objective of high sustainability, which influences the quality of the raw materials wich are selected, of the assemblies which are made, as well as the care taken in all stages of production by a highly qualified workforce.
On-site erection, if necessary with management of the related logistics and handling issues, is also a service marketed by ITS which thus proposes a turnkey offer in relation to the soundproofing of ventilation hardware : design, construction and installation.