Himech Acoustics Engineering

Tiruchirappalli, Tamil Nadu

The suction silencer is used to reduce the suction noise of the compressor/ blower. It is constructed in circular shape. The fluid passes through the annular space of the acoustic packing where the sound energy is absorbed. The straight flow path through annular acoustic cylinder ensures minimum pressure drop

The following data are required to design suction silencer.

• Flow rate
• Temperature
• Inlet size
• Allowable pressure drop

Silenced noise level requirements

The exhaust silencer is used to reduce the exhaust noise of the engine and turbine. The engine silencer is a combination of absorptive and reactive type silencer to attenuate high and low frequency noise. The gas turbine exhaust silencer will be absorptive type silencer. The exhaust silencer will be similar to that of vent silencer. It is generally offered in circular shape.

For the design of the exhaust silencer the following information are needed

• Type ofFluid (Gas (or) Steam)
• Mass flow (Preferable in pounds per hour or kg per hour)
• Temperature and pressure upstream of the control or relief valve
• Line connection to the vent silencer

Silenced noise level requirements

Every industry makes use of safety valves to protect systems against over pressure when these safety valves are opened to vent steam, gas or vapor it is often accompanied by excessive noise levels. Noise level as high as 150 to 160dB (A) are not audible/unacceptable. It will affect the hearing level of employees and complaints may also be received from surrounding residential areas or factories.

Himech Acoustics safety valve silencer will reduce such noise to environmentally acceptable levels. [Such as 85dB (A)] as specified by Indian pollution control boards.

The following process values are required to make the appropriate selection.

• Medium
• Capacity
• Medium temperature
• Pressure before the valve and after the valve
• Sound level required

Connection size

Blow off silencer is a type of vent silencer. The blow down of highly compressed vapor or gas into the open air sets kinetic energy free in the form of high amplitude pressure fluctuations. The result is an extremely high sound pressure level which must be reduced. Such emission can be very effectively be limited with blow-off silencers.

For the design of the silencer the following information is needed

• Type of fluid (Gas or Steam)
• Temperature and Pressure upstream (before) valve
• Permissible sound pressure level at Emission point (in defined distance) E.g.85 dB(A) in 1m distance
• Diameter of inlet nozzle

The fan silencer is used to reduce the suction and discharge noise of the fan. It is an absorptive type silencer and is very effective for high frequency noise attenuation. Consequently fan silencers shall be supplied in rectangular shape.The internal of fan silencer is constructed with series of rectangular baffle with aerodynamic design to offer minimum pressure drop.

The following data are required to design fan silencer.

• Application
• Flow rate
• Temperature
• Fan inlet / outlet size (Depending on application)
• Allowable pressure drop
• Silenced noise level requirements