More About Centrifugal Compressor Silencers
Centrifugal compressors may be single or multi-stage with a large range of flows and pressures. The unsilenced noise levels can exceed (120dBA depending on size, RPM and gas flow. The noise is primarily discrete tones and a broad band of lesser intensity. The predominant frequency and amplitude occur at the blade passing frequency, and the second harmonic. 

Blade passing frequency (Hz) = (N x RPM)/60
Where N = number of blades
RPM = compressor speed

Typically both intake and discharge silencers are required, however, atmospheric intake service is involved only an intake silencer is required. The most effective silencer is an absorptive type (VANEC models 311, 321, 411, & 421).  The silencer should be mounted as close to the compressor as possible to reduce excessive line-radiated noises.
If internal acoustic packing cannot be utilized, a reactive silencer (multi-chambered) with external lagging may be used.

Pressure Drop Factors (PDF)

VANEC Centrifugal Compressor Intake Silencers are designed for use in suppressing the intake noise from high-speed blowers, fans and centrifugal air handling devices with an atmospheric suction.  Available models: 311, 316, 317, 321, 411

VANEC Centrifugal Compressor Exhaust Silencers are designed for use in suppressing the discharge noise from high-speed blowers, fans and centrifugal air handling devices exhausting to atmosphere.  Available models: 416, 417, 421

We can provide silencers in a variety of materials of construction and with ASME pressure vessel design if required.

Recommended Operating Velocity Limits

Centrifugal Compressor Silencer

INDUSTRIAL SILENCERS