The fan noise is one of the most predominant noise sources in Steel, Power & Chemical Industries. The magnitude and intensity of noise will vary depending on fan size, horse power, air flow, type and number of blades, static pressure, rotational speed, etc.
Fans normally deliver a large volume of air at relatively low static pressures usually measured in inches of water. The rotating action of vanes produce a broad band noise spectrum however, the noise in mid to high frequency range is heard to be louder and requires to be treated for achieving noise control.
Generally, silencers are used at intake and discharge of fan installations for treating air borne noise. Fan silencers usually require absorptive type design as they are well known for better attenuation in mid and high frequency range (500-8000 Hz). The effectiveness of absorption material progressively reduces at frequencies above and below this range.
The noise control is achieved by means of absorption. The acoustic energy propagating through the silencer is effectively absorbed into the fibrous absorption material and converted into heat energy. This silencer generally employs straight thru design and has a low pressure drop as it imposes very little restriction to the flow.
The fan silencers are normally selected on the basis of maximum allowable pressure drop at rated flow and the silencing criteria. These silencers are usually sized for around 5000 to 5500 FPM velocity but not exceeding 7500 FPM velocity to prevent excessive self generated noise and aerodynamic noise generation. While selecting the fan silencer, it must be ensured that the flow area throughout the silencer is sufficient to accommodate the air flow without imposing excessive restriction.
Generally Fan silencers are used for Steel & Power plants, Chemical plants, Petrochemical refineries & Oil & Gas Plants with following applications
- Forced draft Fan
- Induced draft fan
- Primary Air Fan
- Secondary Air Fan
- Axial Fans
- Centrifugal type Fans
Input design Data Required
- Air Flow Rate (Actual CMH)
- Temperature (°C)
- Maximum allowable pressure drop (mmwc)
- Inlet / discharge Connection size of the Fan (Inches/ mm )
- Existing noise frequency spectrum ( 63 hz to 8 KHz) as per the table
We specialize in custom designs and also suggest various options to suit your specific requirements.