Introduction

NAP Acoustics Resonator Silencers are ideal for control of noise from large industrial process plants, manufacturing and mining installations, food processing and electrical power generation plants, where control of broadband fan noise with tonal components is critical.

Resonator Silencers, sometimes called Tuned-Dissipative Silencers or "Christmas Tree" Silencers, are suitable for fan silencing when such equipment becomes a source of community noise problems for residents living adjacent to industrial plants.

Resonator Silencer construction consists of Quarter Wave and Helmholtz chambers which generally contain a number of cavities tuned to the fundamental frequency and its first harmonic. Other chambers are tuned to provide attenuation across the full frequency band.

Resonator Silencers are used in dusty or grease laden environments, where conventional absorptive type silencers clog up and become ineffective.

The Resonator Silencer can be readily cleaned in situ, or the splitter elements can be designed to be removable from the casing for external cleaning.

Applications

In commercial applications such as kitchen exhausts, clean air rooms, electronic component manufacture, laboratories and medical facilities where extremely high air quality or low particulate contamination is required, the silencers can be supplied without fibrous infill and with special non-contaminating absorptive, or flow resistive linings. Thus, depending on the technical and environmental requirements, these silencers can be supplied with optional linings as follows :

• Mineral wool or glass fibre
• Acoustic foams or polyester fibre
• Flow resistive facings (no infill at all)

Acoustic Performance