Critical Assessment of Thermal/Acoustical Insulation for Pipe and Duct Noise

摘要

Piping and duct networks are among the major distributors and sources of noise in power plants.This noise is generated primarily by large rotating equipment and devices, primarily valves, witha large pressure drop. Piping and duct noise controls include silencers, thermal/acousticalinsulation (lagging), and special noise control treatments (e.g., low noise valve trims anddiffusers). The effectiveness of acoustical lagging for pipe and duct noise depends on the type ofnoise source, coupling of the piping to equipment or support structures, and the radiatedacoustical frequencies. Pipe lagging acoustical performance has been reported by researchersover the past several decades. Now both ASTM and ISO have issued testing standards for theevaluation of acoustical pipe lagging systems. The ISO standard also provides pipe laggingdesign guidance. This paper reviews and critically assesses pipe lagging as an effective noisecontrol measure and identifies strengths and deficiencies with the two current standards.