Speaker
Description
We present three cases of verified high-performance industrial scale silencer and flue gas system design.First is an exhaust silencer system for reciprocating engine test run, where low frequency noise caused nuisance at nearby dwellings. Measurements identified a low frequency tonal component. Complete exhaust system was redesigned to implement a distributed silencer system, including two reactive silencers. Measurements after installation at dwellings indicated the tonal component attenuation by 25 dB.Second is a recovery boiler with distinct induced draft fan noise. Current silencers had modest noise attenuation and flow performance, probably exacerbating the fan noise generation. Measurements indicated a 400 Hz tonal component. The exhaust system was remodeled to improve the fan performance and a low-loss baffle silencer was designed. Design target was 25 dB at 400 Hz and 20 dB A-weighted noise reduction. Commissioning test verified a 25 dB(A) reduction of stack top noise and pressure loss of under 200 Pa.Third is a large ship where low frequency tonal noise was identified in passenger areas. Engine source measurements revealed the causing excitation. Classical resonators were designed and installed in the exhaust ducts considering system performance. Commissioning measurements indicated attenuation of 15 dB in passenger areas at design frequency.