Silencers

Noise created from unexpected release of gas from a safety valve to atmosphere could often exceed 150 dB (A) at 1 meter. PRAcoustics safety valve silencer will reduce such noise to environmentally acceptable levels (such as 85dB (A) as specified by Indian Pollution Control boards). Design of our single-stage diffuser assembly is in compliance with ASME section 8, division 1 standards. Length, diameter and other parameters of the silencer muffler are optimized based on the flow conditions of the medium and the noise performance requirements. Typical applications include boiler drum safety valves and super heater safety valves.

Residual media steam or gas is let out to the atmosphere through the startup vent valve, during startup or shutdown of a system. This noise produced due to the pressure gradient can be effectively reduced through PRAcoustics Startup Vent Silencers. Design of Startup Vent Silencer is very similar to that of Safety Valve Silencer. The inlet pressure of the gas-stream is reduced to atmoshperic pressure using a diffuser without reducing the exhaust flow rate and causing pressure build-up at the relief valve. The number and size of the diffuser sections depend upon the inlet pressure of the medium and the acoustic requirements. The pressure drop across the diffuser is selected based on the flow conditions of the media to offer a cost-effective silencer design. After the pressure is reduced, the medium is sent through a muffler for better noise performance. Design of our diffuser assembly is in compliance with ASME section 8, division 1 standards. Depending on the size of the diffuser and the silencer muffler upto 70dB of noise can be reduced. Typical applications for startup vent silencer include boiler blow down lines, air compressor vents and gas plant vents.

• Blowoff silencer

  Blowoff silencer is a type of vent silencer. Before beginning the hydro-test for a steam-generation plant or process equipment plant, the plant is cleaned using high-pressure air. This high-pressure air when leaving the pipework will cause a lot of noise. A blow-off silencer is used to muffle out such noises.

• Discharge silencer

  When air or steam or any other medium is discharged out from the compressor, it causes a lot of noise. Discharge silencer is a type of vent silencer specifically used to reduce such noise at the discharge side of the compressor. Depending on the pressure drop requirement of the customer, design of diffuser and muffler are optimized.

• Suction silencer

  When air or steam or any other medium is sucked into the compressor, it causes a lot of noise. Suction silencer is a type of vent silencer specifically used to reduce such noise at the suction side of the compressor. Depending on the pressure drop requirement of the customer, design of diffuser and muffler are optimized. Design of a suction silencer is very similar to that of a discharge silencer.

Flow of media generated by Gas compressors and ejectors will produce a lot of noise when flowing through stream nozzle due to flow-velocity and turbulent motion. This turbulence could cause very high vibration in the pipeline and also lead to structural damage due to mechanical noise transmission through structures. PRAcoustics On-line silencer blocks the transmission of both the gas-borne noise propagating inside the pipe and the structure-borne noise propagating as vibration in the pipe wall. A very minimal pressure drop across the silencer is achieved (20-50 mm of water column as per the requirement of the customer) through profiled passage ways that reduce turbulence at section changes without reducing the pressure.

Flu gases flowing through the stack will create lot of noise. Stack silencers are essential in controlling noise produced in industrial stack exhaust systems. PR Acoustics Stack silencer will reduce the noise with a very minimal pressure drop across the silencer (20-50mm of water column as per customer requirements). For quick installation, we can supply stack silencers as stack inserts that can be attached to the base or top of stacks. Every stack silencer is custom designed based on Acoustic targets, flow requirements, pressure drop, discharge velocity and temperature of the medium.

Fan’s inlet and outlet will have a lot of noise due to high velocity of air or flow medium and due to the blade cutting the flow. PRAcoustics Fan or blower silencer will effectively reduce this noise. Fan silencer or blower silencer shall be supplied in either circular or rectangular design. The silencer shall be of absorptive type installed either at suction side or discharge side of the fan. A series of acoustic splitters arranged parallel inside the silencer casing will ensure minimum pressure drop while cutting the noise down. The aerodynamic design of the splitters will offer minimum resistance to the flow medium.