The spectral characteristics of the noise are mid-low frequencies, and the peak appears at the low frequency 250 Hz octave band. Such low-frequency noise, on the one hand, is not easy to silence and sound insulation, on the other hand, there is almost no air absorption attenuation with distance. Because the opening area of ​​the equipment room is large, it cannot be regarded as a point sound source, but between the point sound source and the surface sound source. Judging from the outdoor sound level value of the air compressor room and the distance from the West Gate, the air compressor noise will have a more serious impact on the West Gate. The open-air pumping station and the cooling tower open-air pumping station and cooling tower are located on the south side of the 1# building, west of the air compressor room, and about 45m away from the west gate. The noise source includes two 30T/h cooling towers, eight pumps and one cooling. The box and the cooling box have three axial fans that vent upward. On-site measurement of pump noise is 86dB, the lower part of the cooling tower is 80dB, the tower is 88dB at the top of the tower, and 76dB outside the cooling box. These devices are not far apart, actually affect each other during measurement, and cannot strictly represent a certain station. The sound level of the device. The biggest external impact is the cooling tower fan noise (in the upper part of the tower), followed by the pump noise and the tower falling water sound. Additional attenuation due to air absorption and obstacles. Cooling tower fans are mainly low-frequency sounds, air absorption is negligible, and no obstacles, $L can be approximated to zero. The sound level LA of a single cool water tower in the west gate is up to 58dB and must be treated. Although the sound source such as the pump is blocked, it cannot be ignored. Polyester Fancy Yarn Cotton Like
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