The noise from the fan is adjusted. Because the sound absorption coefficient of the metal exhaust system tends to zero, the modulated noise is discharged from the chimney. Because the chimney is 25m high, the sweeping range is large, which is the main noise source for disturbing the people. In addition, the curved and forked roads where the working fan and the exhaust fan exhaust pipe are inevitable are easy to cause the oscillation of the wind flow and the splitting interference of the sound wave is also a factor to adjust the noise generation and amplification. As for the noise and motor noise of the induced draft fan itself, it is basically limited to the measuring point and is not the main content of this treatment. During the operation of the induced draft fan, the structural vibration caused by the vibration of the casing and the ground of the machine body radiates noise through the structure generated by the exhaust pipe and the chimney. In order to determine the extent to which structural radiated noise affects the measuring points, we have done the following experiments. When we add proper support to the air vents and exhaust pipe ports of the induced draft fan, loosen the coupling bolts, fill the seals with asbestos ropes at the gaps, and change the original rigid joints to semi-rigid joints. The point noise drops by about 2dB (A). The results show that the structural radiation noise can not be ignored. Appropriate measures should be taken to resolve them. Other issues that should be considered in governance Due to the unreasonable design of the induced draft fan, the induced draft fan is driven close to the exhaust pipe, and the surface temperature of the exhaust pipe is about 200 °C, so that the air temperature at the air inlet of the motor is high, and the room temperature rises in summer. As a result, the motor often has an overheating fault. In order to avoid overheating of the motor, an additional blower is added for forced cooling, and an additional noise source should be solved in the treatment. The basic vibration problem is due to the fact that outside the wall of the induced draft fan, there are residents who use the wall to build a private house. The residents report that when the induced draft fan works, there is obvious vibration inside the room. Because it is a violation of the building can be ignored, but considering the situation as a collateral problem, it is listed as a secondary problem. 4 The treatment measures take into account that the main road leading to the chimney at the intersection of the main induced draft fan and the spare fan exhaust pipe to the induced draft fan room is less than 1 m, resulting in a short silencer pipe, so a honeycomb type muffler is used. Honeycomb type muffler is made up of several small straight tube mufflers in parallel. Because the ratio of the pipe circumference length L to the section S is larger than that of the straight pipe type, it has a higher noise reduction amount and can greatly improve the failure frequency. Dongguan Yoloon Sports Goods Co.,LtD , https://www.yoloonprotections.com