Noise reduction in fossil power plant draft fans

Technical Report · Sat Oct 01 04:00:00 EDT 1983

OSTI ID:5351103

Koopmann, G H; Neise, W

Using a 20 in. dia fan noise testing facility, which was constructed at the University of Houston for this project, it has been demonstrated that a substantial reduction in the noise level of a centrifugal fan which has a pronounced tone can be achieved by incorporating a quarter-wavelength resonator in the fan casing near the cut-off part of the scroll. The resonator is tuned to the blade passing frequency of the fan by adjusting its length. It acts to reduce the level of the tonal component of the noise by cancelling the sound producing pressure pulses generated by the interaction of the fluid leaving the impeller blades with the solid cut-off of the fan casing. By proper tuning of the resonator and placement of the resonator's perforated mouth near the cut-off region where the pressure fluctuations are most intense, reductions of up to 20 dB in the sound pressure level of the blade passing frequency tone have been observed. Integration of the resonator into the fan casing design provides noise level reductions in both inlet and outlet ducts simultaneously. Reductions are independent of changes in duct impedance due to different end conditions. While the noise reduction method is effective over a wide range of aerodynamic loading conditions, it does not adversely affect the performance of the fan.

• Research Organization: Houston Univ., TX (USA). Dept. of Mechanical Engineering
• OSTI ID: 5351103
• Report Number(s): EPRI-CS-3260; ON: DE84920168
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
200200* -- Fossil-Fueled Power Plants-- Waste Management
BLOWERS
CAVITY RESONATORS
DESIGN
ELECTRONIC EQUIPMENT
EQUIPMENT
FOSSIL-FUEL POWER PLANTS
MATHEMATICAL MODELS
NOISE POLLUTION ABATEMENT
POLLUTION ABATEMENT
POWER PLANTS
RESONATORS
TEST FACILITIES
THERMAL POWER PLANTS