Optimal acoustic and mechanical design to guarantee high level performance – up to 60 dB (A) noise attenuation – in extremely safe conditions.
SAI silencers of absorptive type are suitable to provide noise attenuation in the medium and higher frequency octave bands at the intake or exhaust of fan blowers, internal combustion engines, compressors …
Baffle or bulb technology
Absorption silencers are available with a rectangular or cylindrical shape. The absorptive part is made of acoustic panels named baffles (SBP type) or made of an absorptive cylinder (SCA type).
Thickness and length of the acoustic material are calculated according the frequency octave band to attenuate. The space available for the flow generates the speed of the fluid and a pressure drop.
Dedicated software and the engineer experience allow a perfect optimization of the dimension for the silencer considering two criteria:
- Attenuation of the frequency octave band
- Maximum pressure drop required by the application.
To reach the expected performances, the design of an absorption silencer requires the knowledge of additional parameters depending on the process. Among them:
- Type of gas: air, steam, natural gas, nitrogen, …
- Volume flow rate (Nm3/h, …)
- Inlet temperature (°C, °F …)
- Acoustic performance Lp at 1m (dBA)
- Noise level at inlet by octave band without silencer
- Maximum pressure drop (mm CE)
SAI engineers also take into account specific requirement for the fabrication of the equipment to perfectly meet the needs on site:
- Flanges or butt weld at inlet
- Vertical or horizontal installation
- Carbon steel S235JR or P265GH or alloy / stainless steel 304, 316, 321…
- Rain cover or round elbow
- Protective mesh
- Calculation notes considering site conditions (wind, seism…)
- ITP or Manufacturing Quality Plan with customer inspection if required
- Special painting requirement.
Direct flow silencers
Direct silencers (ABD type) are silencers with very low-pressure drop – at constant static pressure – reaching attenuation between 15 to 30 dB (A) at medium frequency octave band. This type of silencer also works as inline silencer.
Options available to take into account very diverse needs:
- Design as inline silence rat constant pressure up to 200 bars.
- Pressure Equipment Directive 2014/68/UE
- Mechanical design calculated according CODAP or ASMEVIII
- Dish ends at entry / exit depending on static pressure
- Removable absorptive part for hydraulic test