论文部分内容阅读
电力工业采用的引风机噪声声功率级为125～140dB,在半英里外的声压级可达60～75dB.70年代初采用的平行片式阻性消声器(图1a),由于积聚灰尘,使性能约下降70%.两年后测量表明,在叶片频率处约减少15dB,并在谐频处减少约3dB.当积灰清除后,原有消声量大都恢复.开孔式消声器(图(1b、c、d)的中间板的两面均装有控制基频的孔,并在开孔的两面敷设玻璃棉或矿棉.在充满灰尘的气流中应用数年的开孔式消声器的实测声学性能
The induced noise level used by the electric power industry is 125-140dB and the sound pressure level is 60-75dB within half a mile.It is due to the accumulation of dust Performance decreased about 70% after two years of measurement showed that the blade frequency at about 15dB reduction, and reduction in the harmonic about 3dB.When the dust cleared, the original muffler volume mostly recovered.An open muffler (Figure 1b , C, d) Both sides of the middle plate are provided with holes for controlling the fundamental frequency and glass wool or mineral wool is laid on both sides of the openings. The measured acoustic performance of open-ended mufflers for years in dusty air flows