Dissipative Acoustic Silencer
The subject technology is a sound absorption device to moderate the sound effect of a machine. Noise reduction can be achieved by modification of source or path or receiver. Among these, modification of path is most practicable. For intakes and exhausts of air/gas handling systems, Dissipative Acoustic silencers is one such solution. These silencers attenuate noise in ducts through which gas/air flows by baffling process. The silencers are made up of ducts filled with spaced baffles. They work on the principle of sound absorption for reducing the noise. Dissipative acoustic silencer is a noise control device for ducts in which gas flows. Broadband sound attenuation can be achieved by using these silencers. The silencer works on the principle of sound absorption through its baffles. Each baffle consists of a perforated metallic sheet filled with sound absorbing material. Silencer attenuation takes place by ing dissipated sound energy into heat. The technique was employed in developing acoustic silencers for various shipboard equipment such as Gas Turbines and Ventilation fans.
Dissipative acoustic silencer is an important noise control device which is widely used to attenuate the noise in ducts through which gas flows and in which the broadband sound attenuation must be achieved which a minimum of pressure drop across the silencer. Dissipative silencers attenuate sound by converting the acoustical energy propagating in the passages into heat. NSTL has developed acoustic silencers for Gas turbine intake and Ventilation fans. With these silencers, 10 to 12 dB (A) noise reduction was achieved.