In many industrial plants, the mile-long pipes, which are supposed to transport gas, represent a major noise source. This noise is generated by control valves, compressors or fans located inside of the pipe. In order to reduce pipe radiated noise efficiently, an inline silencer must be placed into the pipe. An absorption silencer is the most favorable solution for a broad-band sound reduction. The incoming sound wave will be deflected into the absorption material where the sound energy will be converted into heat.
Absorption silencers are suitable for the sound reduction of middle and high frequencies. The absorption material has to be adjusted to the characteristic acoustic impedance of the gas. For most gases under light or moderate pressure (<50 bar) this adjustment can be done. For high-pressurized gases with very high acoustic impedances, conventional absorption materials are no longer sufficient. In this case or for low frequency reductions, resonator silencers are quite more efficient.
Our silencers consist of a pressure-tested steel casing in accordance with the required standards (ASME, EN, PED, etc.). Absorption parts filled with high absorptive mineral wool covered by a special acoustic layer, a finely woven stainless- steel mesh and perforated plates. The materials are resistant to humidity, heat and are non-flammable. All absorbing components are welded constructions and are fixed in the silencer by welding.
These silencers have successfully been installed in many different noise control applications. For an appropriate silencer design, we need exact data of the noise source (octave-band spectrum of the sound power level inside the silencer inlet nozzle). On the basis of calculations, we receive the required insertion loss of the silencer. Thus, we obtain the required sound power or sound pressure level at the external pipe system behind the silencer.
