Industrial fans occupy a place of choice for those who are concerned about the sound environment, because their operation is always accompanied by acoustic emissions which are not negligible even though they are in fairly widespread use, for many processes, as soon as it is necessary to set in motion, in various contexts, non-pressurized gases in which the noise emitted by different sound sources usually present in aeraulic networks is propagated, to which is added their self noise.
In a flue gas treatment facility, industrial fans outlet is a very powerful noise source potentially causing sound nuisance for personnel of the operator operating in the vicinity as well as for the neighborhood (including long distance, a fortiori in the case of tall stacks). It is often necessary to use in such cases a soundproofing equipment of high technology to ensure compliance of the installation 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. In fact fans outlet silencers in a flue gas treatment facility must have high acoustic performance (the overall sound power level to consider is often close from 130 dBA and noise emissions are with a very wide frequency spectrum) in a context where high temperatures (around 180 °C or sometimes more) and very high gas flow rates (which are counted in decades of kg/s) must be considered: great care must be taken when sizing to limit the total pressure loss directly impacting the productivity of the plant.
ITS will participate in the construction of 2 silencers at industrial fans outlet in the context of a project of erection of a flue gas treatment unit for of a power generation plant in Finland.
Of course, this soundproofing equipment must have a sound transmission loss particularly important. But in addition, with a flow rate able to reach 50 kg/s at a temperature of 180°C, the flow rate of exhaust gas into the silencer will be very high, requiring a specific design of the silencer in particular with respect to issues related to aerodynamic and to self-noise.
Therefore, the simulation of the insertion loss (with or without flow noise) as well as of the total pressure loss of the silencer (whose splitters will be equipped of extremities with a special aerodynamic shaping) in the foreseen operation conditions was performed by the means of the software SILDIS®.
Specific absorbent materials wich properties must satisfy both the ambitious goals of acoustic performance and also to requirements related to mechanical and thermal extreme solicitations as well as to physicochemical aggression will be incorporated into the design as required for those silencers at outlet of industrial fans.
In addition, the course of this project shows - once again - the possibilities for design and optimization of soundproofing equipment of the software SILDIS®, whose computing power and reliability, as well as whose versatility made of it a choice tool for the selection of products and construction systems for many projects of sound insulation.
It is therefore a good opportunity for the human resource of ITS and of its commercial partners to mobilize their skills as part of an industrial soundproofing project for which experience will count for the achievement of the various objectives reting to this project of preservation of sound environment.